FORM 2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION [See section 10, Rule 13] ENCODING METHOD, ENCODER, AND DECODER PANASONIC CORPORATION, A CORPORATION ORGANIZED AND EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 1006, OAZA KADOMA, KADOMA-SHI, OSAKA 571-8501, JAPAN. THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED. DESCRIPTION Technical Field The present invention relates to a Low-Density Parity-Check Convolutional Code (LDPC-CC) encoding method, encoder, and decoder. Background Art In recent years, attention has been attracted to a Low-Density Parity-Check (LDPC) code as an error correction code that provides high error correction capability with a feasible computational complexity. Due to its high error correction capability and ease of implementation, an LDPC code has been adopted in an error correction encoding method for IEEE802.11n high-speed wireless LAN systems, digital broadcasting systems, and so forth. An LDPC code is an error correction code defined by low-density parity check matrix H. An LDPC code is a block code having a block length equal to number of columns N of parity check matrix H, A random LDPC code, array LDPC code, and QC-LDPC code (QC: Quasi-Cyclic) are proposed in Non-Patent Document 1, Non-Patent Document 2, and Non-Patent Document 3, for example. However, a characteristic of many current communication systems is that transmission information is transmitted collected together into variable-length packets and frames, as in the case of Ethernet (registered trademark). A problem with applying an LDPC code, which is a block code, to a system of this kind is, for example, how to make a fixed-length LDPC code block correspond to a variable-length Ethernet (registered trademark) frame. With IEEE802.11n, adjustment of the length of a transmission information sequence and an LDPC code block length is performed by executing padding processing or puncturing processing on a transmission information sequence, but it is difficult to avoid a change in the coding rate and redundant sequence transmission due to padding or puncturing. In contrast to this kind of LDPC code of block code „ (hereinafter referred to as "LDPC-BC: Low-Density Parity-Check Block Code"), LDPC-CC (Low-Density Parity-Check Convolutional Code) allowing encoding and decoding of information sequences of arbitrary length have been investigated (see Non-Patent Document 1 and Non-Patent Document 1, for example}. An LDPC-CC is a convolutional code defined by a low-density parity-check matrix, and, as an example, parity check matrix HT[0,n] 0f an LDPC-CC for which coding rate of R = l/2 ( = b/c) is shown in FIG.l. Here, element h,(m)(t) of HT[0,n] has a value of 0 or \. All elements other than hi(m)(t) are 0. M represents the LDPC-CC memory length, and n represents the length of an LDPc codeword. As shown in FIG.l, a characteristic of an LDPC-CC parity check matrix is that it is a parallelogram-shaped matrix in which 1 is placed only in diagonal terms of the matrix and neighboring elements, and the bottom-left and top-right elements of the matrix are zero. An LDPc encoder defined by parity check matrix HT[0,n] when hi(0)(t)=l and h2(0)(t) = l here is represented by FIG.2. As shown in FIG.2, an LDPC encoder is composed of M+l shift registers of bit-length c and a modulo 2 adder. Consequently, a characteristic of an LDPC encoder is that it can be implemented with extremely simple circuitry in comparison with a circuit that performs generator matrix multiplication or an LDPC-BC encoder that performs computation based on backward (forward) substitution. Also, since the encoder in FIG.2 is a convolutional code encoder, it is not necessary to divide an information sequence into fixed-length blocks when encoding, and an information sequence of any length can be encoded. Non-Patent Document 1: R. G. Gallager, "Low-density parity check codes," IRE Trans. Inform. Theory, IT-8, pp-21-28, 1962. Non-Patent Document 2: D. J. C. Mackay, "Good error-correcting codes based on very sparse matrices," IEEE Trans. Inform. Theory, vol.45, no.2, pp$99-431, March 1999. Non-Patent Document 3: J. L. Fan, "Array codes as low-density parity-check coties," proc. of 2nd Int. Symp. on Turbo Codes, pp.543-546, Sep. 2000. ^Non-Patent Document 4: Y. Kou, S. Lin, and M. P. C. Fossorier, "Low-density parity-check codes based on finite geometries: A rediscovery and new results," IEEE Trans. Inform. Theory, vol.47, no.7, pp2711-2736, Nov. 2001. Non-Patent Document 5: A. J. Felstorom, and K. Sh. Zigangirov, "Time-Varying Periodic Convolutional Codes With Low-Density Parity-Check Matrix,"IEEE Transactions on Information Theory, Vol. 45, No.6, pp21 81-2191, September 1999. Non-Patent Document 6: R. M. Tanner, D. Sridhara, A. Sridharan, T. E. Fuja, and D. J. Costello Jr., "LDPC block and convolutional codes based on circulant matrices," IEEE Trans. Inform. Theory, vol.50, no.12, pp.2966-2984, Dec. 2004. Non-Patent Document 7: G. Richter, M. Kaupper, and K. Sh. Zigangirov, "Irregular low-density parity-Check convolutional codes based on protographs, "Proceeding of IEEE ISIT 2006, pP1633-1637. Non-Patent Document 8: R. D. Gallager, "Low-Density Parity-Check Codes," Cambridge, MA: MIT Press, 1963. Non-Patent Document 9: M. P. C. Fossorier, M. Mihaljevic, and H. Imai, "Reduced complexity iterative decoding of low-density parity-check codes based on belief propagation," IEEE Trans. Commun., vol.47., no.5, pp.673-680, May 1999. Non-Patent Document 10: J. Chen, A. Dholakia, E. Eleftheriou, M. P. C. Fossorier, and X.-Yu Hu,"Reduced-complexity decoding of LDPC codes," IEEE Trans. Commun., vol.53., no.8, pp.1288-1299, Aug. 2005. Non-Patent Document 11: Y. Ogawa, "Sum-product decoding of turbo codes," M. D. Thesis, Dept. Elec. Eng., Nagaoka Univ. of Technology, Feb. 2007. Non-Patent Document 12: S. Lin, D. J. Jr., Costello, "Error control coding : Fundamentals and applications," Prentice-Hall.12.3 pp.53 8-544,1 3 .4 pp.640-645 Non-Patent Document 13: Tadashi Wadayama, "Low-Density Parity-Check Code and the decoding method", Triceps., p.26-27. Non-Patent Document 14: A. Pusane, R. Smarandache, P. Vontobel, and D. J. Costello Jr., "On deriving good LDPC a convolutional codes from QC LDPC block codes," Proc. of IEEE ISIT 2007, pp.1221-1225, June 2007. Non-Patent Document 15: A. Sridharan, D. Truhachev, M. Lentmaier, D. J. Costello, Jr., K. Sh. Zigangirov, "Distance Bounds for an Ensemble of LDPC Convolutional Codes," IEEE Transactions on Information Theory, vol.53, no.12, Dec. 2007. Non-Patent Document 16: A. Pusane, K. S. Zigangirov, and D. J. Costello Jr., "Construction of irregular LDPC convolutional codes with fast encoding," Proc. of IEEE ICC 2006, pp. 1 1 60-1 1 65 , June 2006. Non-Patent Document 17: Hiroyuki Yashima, "Convolutional code and Viterbi decoding method", Triceps., p.20-29. Non-Patent Document 18: R. Johannesson, and K. S. Zigangirov, "Fundamentals of convolutional coding," IEEE Press, pp.337-344 Disclosure of Invention Problems to be Solved by the Invention Here, in the case of a block code, if the number of bits of transmission data is not an integral multiple of the code block length, it is necessary to transmit redundant bits. Therefore, when an LDPC-BC with a large block size or an LDPC-CC with a large protograph size is used, the number of redundant bits transmitted is large. In particular, when a packet for which the number of transmission data bits is small is transmitted in packet communication, there is a problem of data transmission efficiency decreasing significantly due to the transmission of redundant bits. However, it is difficult to solve this problem with the LDPC codes disclosed in Non-Patent Document 1 through Non-Patent Document 7. Solving this problem requires an LDPC-CC to be designed that can be configured using a smaller protograph size than in Non-Patent Document 1 through Non-Patent Document 7. In this regard, if an LDPC-CC is created from a convolutional code, the protograph size can be made smaller than in Non-Patent Document 1 through Non-Patent Document 7. Thus, a technique is required for improving received quality when an LDPC-CC is created from a convolutional code and an information sequence is transmitted after undergoing error correction encoding using the LDPC-CC. The present invention has been implemented taking into account the problems described above, and it is an object of the present invention to provide an LDPC-CC encoding method, encoder, and decoder that enable good received quality to be obtained when an LDPC-CC is created from a convolutional code and an information sequence is transmitted after undergoing error correction encoding using the LDPC-CC. Means for Solving the Problem One aspect of an encoding method according to the present invention is an encoding method that creates a Low-Density Parity-Check Convolutional Code (LDPC-CC) of a time varying period of 3g (where g is a positive integer), and has: a step of supplying the first through 3g'th parity check polynomials, in an LDPC-CC defined based on, in a parity check polynomial represented by Equation 168-1, a first parity check polynomial, (a#i,i,i%3, a#i,i,2%3, a#i,i,3%3), (a#i,2,i%3, a#i,2,2%3, a#i,2,3%3), ..., (a#i,n-i,i%3, a#i,n-i,2%3, a#i,n-i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and (b#i,i%3, bn.2%3, b#i,3%3) is any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and a second parity check polynomial in which, in a parity check polynomial represented by Equation 168-2, (a#2.i.i%3, a#2,i(2%3, a#2,i,3%3), (a#2?2,i%3, a#2,2,2%3, a#2,2,3%3), ..., (a#2,n-i,i%3, a#2,n-i,2%3, a#2,„-i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and (b#2,i%3, b#2,2%3, b#2,3°/°3) is any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and a kk'th parity check polynomial in which, in a parity check polynomial represented by Equation 168-kk (where kk = 3, 4 3g-l), (a#kk,i,.%3, a#kk,i,2%3, a#kk,i,3%3), (a#kk,2,i%3, a#kk,2,2%3, a#kk,2>3%3), ..., (a#kk>n-i,i%3, a#kk,n-i,2%3, a#kk,n-i,30/o3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and (b#kk,i%3, b#kk,2%3, b#kk,3%3) is any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and a 3g'th parity check polynomial in which, in a parity check polynomial represented by Equation 168-3g, (a#3giipi%3, a#3g,i>2%3, a#3g,i,3%3), (a#3gi2,i%3, a#3g,2,2%3, a#3g,2,3%3), ..., (a#3B,n-i,i%3, a«3g,„.i,2%3, a#3g,„-i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and (b#3g,,%3, b*36,2%3, b#3g,3%3) is any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), supplying the first through 3g'th parity check polynomials; and a step of acquiring an LDPC-CC codeword by linear computation using the first through 3g*th parity check polynomials and input data. One aspect of an encoder according to the present invention is an encoder that creates a Low-Density Parity-Check Convolutional Code (LDPC-CC) from a convolutional code, and employs a configuration having a parity calculation section that finds a parity sequence by means of the above-described encoding method. One aspect of a decoder according to the present invention is a decoder that decodes a Low-Density Parity-Check Convolutional Code (LDPC-CC) using Belief Propagation (BP), and employs a configuration having: a row processing computation section that performs row processing computation using a parity check matrix corresponding to a parity check polynomial used by the above-described encoder; a column processing computation section that performs column processing computation using the parity check matrix; and a determination section that estimates a codeword using computation results of the row processing computation section and the column processing computation section. Advantageous Effects of Invention According to the present invention, by focusing on a convolutional code for a small-size protograph, and making a parity check polynomial of a convolutional code a protograph, received quality can be improved and the number of redundant bits transmitted can be reduced in an LDPC-CC design method. Furthermore, by adding "1" to a predetermined position of an approximate lower triangular matrix or upper trapezoidal matrix of parity check matrix H, and increasing the order of a parity check polynomial of a convolutional code at this time, good received quality can be obtained in a receiving apparatus by performing BP decoding or approximated BP decoding using the created LDPC-CC parity check matrix. Brief Description of Drawings FIG.l shows an LDPC-CC parity check matrix; FIG.2 shows a configuration of an LDPC-CC encoder; FIG.3 shows an encoder with a (7, 5) convolutional code; FIG.4 shows a parity check matrix of a (7, 5) convolutional code; FIG.5 shows a parity check matrix of a (7, 5) convolutional code; FIG.6 shows an example of a case in which "1" is added to an approximate lower triangular matrix of the parity check matrix in FIG.5; FIG.7 shows an example of the configuration of an LDPC-CC parity check matrix according to Embodiment 1; FIG.8 shows a parity check matrix of a (7, 5) convolutional code; FIG.9 shows an example of the configuration of an LDPC-CC parity check matrix according to Embodiment 1; FIG.10 shows a parity check matrix of a (7, 5) convolutional code; FIG. 11 shows an example of a case in which "1" is added to an upper trapezoidal matrix of the parity check matrix in FIG.5; FIG.12 shows an example of the configuration of an LDPC-CC parity check matrix according to Embodiment 2; FIG.13 shows an example of the configuration of a parity check matrix upon termination according to Embodiment 3; FIG.14 shows an example of the configuration of a parity check matrix upon termination according to Embodiment 3; FIG.15 shows an example of the configuration of a parity check matrix upon termination according to Embodiment 3; FIG.16 illustrates a method of creating an LDPC-CC from a convolutional code; FIG.17 shows an example of the configuration of an LDPC-CC parity check matrix according to Embodiment 7; FIG.18 shows an example of the configuration of an LDPC-CC parity check matrix of a time varying period of 1 (according to Embodiment 7; FIG.19 shows an example of the configuration of an LDPC-CC parity check matrix of a time varying period of m according to Embodiment 7; FIG.20A is a drawing for explaining a number of puncturing patterns; FIG.20B shows the relationship between an encoding sequence and a puncturing pattern; FIG.20C shows the number of parity check polynomials that must be checked in order to select a puncturing pattern; FIG.21A shows an example of the configuration of an LDPC-CC parity check matrix of a time varying period of 2; FIG.21B shows an example of the configuration of an LDPC-CC parity check matrix of a time varying period of 4; FIG.22 illustrates a method of creating an LDPC-CC from a convolutional code of a coding rate of 1/n; FIG.23 illustrates a method of creating an LDPC-CC from a convolutional code of coding rate of 1/n; FIG.24 shows an example of the configuration of an encoder; FIG.25 shows an example of the configuration of an encoder; FIG.26 shows a configuration of a decoder using a sum-product decoding algorithm; FIG.27 shows an example of the configuration of a transmitting apparatus; FIG.28 shows an example of a transmission format; FIG.29 shows an example of the configuration of a receiving apparatus; FIG.30 shows an example of the configuration of an encoding section; FIG.31 shows an example of the configuration of an LDPC-CC encoding section using a parity check matrix in which "1" is added to an upper trapezoidal matrix of the parity check matrix; FIG.32 shows an example of the configuration of an LDPC-CC parity check matrix of a time varying period of 2; FIG.33 shows an example of the configuration of an LDPC-CC parity check matrix of a time varying period of 7; FIG.34 shows the configuration of an LDPC-CC parity check matrix according to another Embodiment 7; FIG.35 is a drawing for explaining a general puncturing method; FIG.36 shows the correspondence between transmission codeword sequence v and LDPC-CC parity check matrix H according to a general puncturing method; FIG.37 is a drawing for explaining puncturing method according to another Embodiment 7; FIG.38 shows the correspondence between transmission codeword sequence v and LDPC-CC parity check matrix H according to another Embodiment 7; FIG.39 is a block diagram showing another main configuration of a transmitting apparatus according to another Embodiment 7; FIG.40 shows an example of a puncturing pattern according to another Embodiment 7; FIG.41 shows another puncturing pattern according to another Embodiment 7; FIG.42 shows another puncturing pattern according to another Embodiment 7; FIG.43 shows another puncturing pattern according to another Embodiment 7; FIG.44 shows another puncturing pattern according to another Embodiment 7; FIG.45 is a drawing for explaining decoding processing timing; FIG.46 shows an FEC encoder; FIG.47 shows a structure of an LDPC convolutional encoder; FIG.48 shows a structure of an LDPC-CC encoder; FIG.49 is a block diagram showing another main configuration of a transmitting apparatus according to another Embodiment 9; FIG.50 shows the relationship between the maximum orders j and second orders of two polynomials; FIG.51 is a drawing for explaining the relationship between the maximum orders and second orders of two polynomials; FIG.52 shows an example of a wireless communication system according to another Embodiment 11; FIG.53 shows anther example of a wireless communication system according to another Embodiment 11; FIG.54 shows an example of the configuration of LDPC-CC parity check matrix H of a coding rate of 2/3 and a time varying period of 2; FIG.55A shows an example of the configuration of an LDPC-CC parity check matrix of a coding rate of 2/3 and a time varying period of m; FIG.55B shows an example of the configuration of an LDPC-CC parity ch^ck matrix of a coding rate of (n-l)/n and a time varying period of m; FIG.56 shows examples of a first sub-matrix and second sub-matrix according to another Embodiment 12; FIG.57 shows a configuration example of LDPC-CC parity check matrix H of a coding rate of 1/2 and a time varying period of 2 comprising a first sub-matrix and second sub-matrix; FIG.58 shows examples of a first sub-matrix and second sub-matrix according to another Embodiment 12; FIG.59 shows a configuration example of LDPC-CC parity check matrix H of a coding rate of 2/3 and a time varying period of 2 comprising a first sub-matrix and second sub-matrix; FIG.60 is a drawing provided to explain the design method described in Non-Patent Document 16; FIG.61 shows a sub-matrix provided to explain Theorem 1; FIG.62 shows a sub-matrix provided to explain Theorem 1; FIG.63 shows a sub-matrix provided to explain Theorem 1; FIG.64 shows a sub-matrix provided to explain Theorem 2; FIG.65 shows a sub-matrix provided to explain Theorem 2; FIG.66 shows a sub-matrix provided to explain Theorem 2; FIG.67A shows parity check polynomials and a parity check matrix H configuration of an LDPC-CC of a time varying period of FIG.67B shows the belief propagation relationship of terms relating to X(D) of "check equation #1" through "check equation #3" in FIG.67A; FIG.67C shows the belief propagation relationship of terms reixting to X(D) of "check equation #1" through "check eguation #6"; FIG.68 shows a correspondence relationship of parity check matrix H of an LDPC-CC of a time varying period of 3, transmission sequence u, and parity patterns in accordance with [Condition #1] and [Condition #2]; and FIG.69 shows another correspondence relationship of LDPC-CC parity check matrix H of a time varying period of 3, transmission sequence u, and parity patterns in accordance with [Condition #1] and [Condition #2]. Best Mode for Carrying Out the Invention Now, embodiments of the present invention will be described in detail with reference to the accompanying drawings. (Embodiment 1) In Embodiment 1, a method of designing a new LDPC-CC from a (7, 5) convolutional code will be described in detail. FIG.3 shows a configuration of an encoder with a (7, 5) convolutional code. The encoder shown in FIG.3 has shift registers 101 ancf 102, and exclusive OR circuits 103, 104, and 105. The encoder shown in FIG.3 outputs output x and parity p for input x. This code is a systematic code. In the present invention, the fact that a convolutional code, which is a systematic code, is used is important. This point will be explained in detail in Embodiment 2. A convolutional code of a coding rate of 1/2 and generating polynomial G=[l Gi(D)/G0(D)] will be considered as an example. At this time, Gi represents a feed-forward polynomial and Go represents a feedback polynomial. If polynomial representation of an information sequence (data) is X(D), and a parity sequence polynomial representation is P(D), a parity check polynomial is represented as shown in Equation 1 below. [1] G1(D)x(D)+Go(D)P(D)=0 ... (Equation 1) Here, D is a delay operator. FIG.4 shows information relating to a (7, 5) convolutional code. A (7, 5) convolutional code generating polynomial is represented as G=[l (D2+l)/ (D2 + D + l)]. Therefore, a parity check polynomial is as shown in Equation 2 below. [2] {p2 + \)x(D)+{p7 + D + l)p(D}=0 ... (Equation 2) Here, data at point in time i is represented by Xj, and parity by Pi, and transmission sequence Wi is represented as Wj = (Xi, Pi). Then transmission vector w is represented as w=(Xi, Pi, X2, P2, •••, X;, P;)T. Thus, from Equation 2, parity check matrix H can be represented as shown in FIG.4. At this time, the relational equation in Equation 3 below holds true. [3] Hw=0 ... (Equation 3) Therefore, in a receiving apparatus, parity check matrix H is used, and decoding can be performed using Belief Propagation (BP) decoding, min-sum decoding similar to BP decoding, offset BP decoding, Normalized BP decoding, shuffled BP decoding, or suchlike belief propagation, as shown in Non-Patent Document 8 through Non-Patent Document 10. Here, in the parity check matrix in FIG.4, the part to the lower-left of row number = column number "l"s (the part to the lower-left of 201 in FIG.4) is defined as an approximate lower triangular matrix. The part to the upper-right of row number = column number "l"s is defined as an upper trapezoidal matrix. Next, a design method for an LDPC-CC according to the present invention will be described in detail. In order to implement an encoder with a simple configuration, a method is adopted whereby "1" is added to an approximate lower triangular matrix of parity check matrix H for a (7, 5) convolutional code shown in FIG.4. Here, it will be assumed as an example that "l"s added to *the parity check matrix in FIG.4 comprise one data "1" and one parity "1." When "1" is added to data and parity to the approximate lower triangular matrix of parity check matrix H in FIG.4, a check polynomial is represented as shown in Equation 4 below. In Equation 4, a>3 and p>3. [4] (Da+D2+l)x(D)+(D8+D2+D+l)p(D)=O ... (Equation 4) Therefore, parity P(D) is represented as shown in Equation 5 below. [5] p(D)=(Da+D2+1)x(D8+D2+D)p(D) ... (Equation 5) When "1" is added to an approximate lower triangular matrix of a parity check matrix, since DPP(D), D2P(D), and DP(D) are past data and are known values, parity P(D) can easily be found. Next, positions of added "l"s will be described in detail using FIG. 5. In FIG. 5, reference code 301 indicates a "1" relating to decoding of data X; of point in time i, and reference code 302 indicates a "1" relating to decoding of parity Pi of point in time i. Dotted line 303 is a protograph involved in propagation of external information for data Xi and parity Pi of point in time i when one BP decoding operation is performed. That is to say, belief from point in time i-2 to point in time i + 2 is involved in propagation. Boundary line 305 is drawn vertically for the rightmost "1" (304) of protograph 303. Then boundary line 307 is drawn for the leftmost "1" (306) adjacent to boundary line 305. Then "1" is added somewhere in area 308 so that belief from boundary line 305 onward is propagated to data X1 and parity Pi of point in time i. By this means, a probability that could not be obtained before adding "1," that is, belief other than from point in time i-2 to point in time i + 2, can be propagated. In order to propagate a new probability, it is necessary to add to area 308 in FIG.5. Here, the width from the rightmost "1" to the leftmost "1" in each row of parity check matrix H in FIG.5 is designated L. Thus far, a position at which "1" is added has been described in the column direction. Considering this in the row direction, in the parity check matrix in FIG.4, "1" is added at a position L-2 or more to the left of the leftmost "1." Also, when described in terms of a check polynomial, a should be set to 5 or above and p to 5 or above in Equation 4. This will be considered represented by a general expression. A general expression for a parity check polynomial of a convolutional code is represented as shown in Equation 6 below. [6] (lf+-+l)x{D)+[if+-~+I)P(D)=0 ... (Equation 6) When "1" are added as data and parity to the approximate lower triangular matrix of parity check matrix H, a check polynomial is represented as shown in Equation 7 below. [7] {jf+rf+-+i]x{D)+(ff+if+ ■+\)F(D)=0 ... (Equation 7) In this case, a should be set to 2K+1 or above and (3 to 2K+1 or above, where K>2. FIG.6 shows an example of a case in which "1" is added to the approximate lower triangular matrix of the parity check matrix in FIG.5. When "1" is added for data and parity of all points in time, the parity check matrix is represented as shown in FIG.7. FIG.7 shows an example of the configuration of an LDPC-CC parity check matrix according to this embodiment- In FIG.7, "l"s inside areas 501 and 502 are added "l"s, and a code having parity check matrix H is an LDPC-CC according to this embodiment. At this time, a check polynomial is represented as shown in Equation 8 below. [8] (D5+D2+1)x{D)+{D7+D2+D+1)p{D)=0 ... (Equation 8) Creating an LDPC-CC from a convolutional code by adding "l"s to an approximate lower triangular matrix of parity check matrix H in a transmitting apparatus as described above enables a receiving apparatus to obtain good received quality by performing BP decoding or approximated BP decoding using a parity check matrix of the created LDPC-CC. In this embodiment, a case has been described in which one "1" is added for data and for parity respectively, but the present invention is not limited to this, and a method may also be used, for example, whereby "1" is added for either data or parity. As an example, consider a case in which there is no Dp in Equation 7 above. At this time, a receiving apparatus can obtain good received quality if a is set to 2K+1 or above. Conversely, to consider a case in which there is no Da in Equation 7, at this time the receiving apparatus can obtain good received quality if p is set to 2K+1 or above. Received quality is also gieatly improved by a code in which a plurality of "l"s are added for both data and parity. For instance, as an example of a case in which a plurality of "l"s are inserted, a parity check polynomial of a certain convolutional code is assumed to be represented by Equation 9. In Equation 9, K>2. [9] {jf+■■■+\)x{D)+(if+-+l)F(D)=0 ... (Equation 9) When a plurality of " 1"s are added as data and parity in an approximate lower triangular matrix of parity check matrix H, a check polynomial is represented as shown in Equation 10 below. [10] ijf1+--+If"+I?+---+l}x(D)+(jfJ+--+iJ*+i?+-+])F(D)=0 ... (Equation 10) In this case, good received quality can be obtained by a receiving apparatus if ■■- (Equation 12) However, good received quality can still be obtained by the receiving apparatus if at least one of p1} ..., pm is 2K+1 or above. Next, a method of designing an LDPC-CC from a parity check polynomial different from Equation 2 of a (7, 5) convolutional code will be described in detail. Here, as an example, a case will be described in which two "l"s are added for data and two "l"s are added for parity. Parity check polynomials different from Equation 2 of a (7, 5) convolutional code are shown in Non-Patent Document 11. One example is represented as shown in Equation 13 below. [13] bf+£f+rt+l}x(D)+(£?+tf+zt+D+i)p(D)=0 ... (Equation 13) In this case, parity check matrix H can be represented as shown in FIG. 8 . Here, a case will be described in which two "l"s are added to both data and parity for the parity check matrix in FIG.8. When two "l"s are added to both data and parity in the approximate lower triangular matrix of parity check matrix H in FIG.8, a check polynomial is represented as shown in Equation 14 below. [14] ty+zP+zf+lf+tf+ijxfy+ty+jF+tf+zf+tf+D+i)^)^ ... (Equation 14) Therefore, parity P(D) can be represented as shown in Equation 15 below. [15] l{D)=&+if1+i?+if+tf+l)x(D)+(^+rfi+if+if+rt+D)p(D) ... (Equation 15) Thus, when "1" is added to an approximate lower riangular matrix of a parity check matrix, since DplP(D), Dp2P(D), D9P(D), D8P(D), D3P(D) and DP(D) are past data and are known values, parity P(D) can easily be found. Good received quality can be obtained by a receiving apparatus if ai, tt2 are set to 19 or above and pi, £2 are set to 19 or above in order to obtain the same kind of effect as described above. As an example, it will be assumed that settings ai=26, Select a convolutional code that gives good characteristics. <2> Generate a check polynomial for the selected convolutional code (for example, Equation 6). It is important to use the selected convolutional code as a systematic code. A check polynomial is not limited to one as described above. It is necessary to select a check polynomial that gives good received quality. At this time, it is preferable to use an equivalent check polynomial of a higher order than a check polynomial generated from a generating polynomial (see Non-Patent Document ll). <3> Create parity check matrix H for the selected convolutional code. <4> Consider probability propagation for data or (and) parity, and add "l"s to the parity check matrix. Positions at which "1" is added are as explained above. In this embodiment, a method of creating an LDPC-CC from a (7, 5) convolutional code has been described, but the present invention is not limited to a (7, 5) convolutional code, and can be similarly implemented using another convolutional code. Details of generating polynomial G of a convolutional code that gives good received quality at this time are given in Non-Patent ♦ Document 12. As described above, according to this embodiment, by having a transmitting apparatus set oj, ..., an to 2K+1 or above and set pi, ..., pm to 2K+1 or above in Equation 10 and create an LDPC-CC from a convolutional code, a receiving apparatus can obtain good received quality by performing BP decoding or approximated BP decoding using a parity check matrix of the created LDPC-CC. Also, when an LDPC-CC is created from a convolutional code, the size of a protograph, that is, a check polynomial, is much smaller than that of a protograph shown in Non-Patent Document 6 or Non-Patent Document 7, and therefore the number of redundant bits generated when transmitting a packet for which the number of transmission data bits is small can be reduced, and the problem of a decrease in data transmission efficiency can be suppressed. (Embodiment 2) In Embodiment 2, a method of designing a new LDPC-CC from a (7, 5) convolutional code will be described in detail. Especially, a method of adding " 1"s to an upper trapezoidal matrix of a parity check matrix will be described in detail. Details of a parity check polynomial and parity check matrix H configuration of a (7, 5) convolutional code are as described in Embodiment 1. A design method for an LDPC-CC according to the present invention will be described in detail. In order to implement an encoder with a simple configuration, in the invention of this embodiment a method is adopted whereby "1" is added to an upper trapezoidal matrix of parity check matrix H for a (7, 5) convolutional code shown in FIG.10. Here, it will be assumed as an example that " 1 " s added to the parity check matrix in FIG.10 are added to data and parity. In this case, a check polynomial is represented as shown in Equation 16 below. In Equation 16, a1, ..., an„<-l, and pi, ..., pm<-l. [16] (c?+l+Zf'+- ■+£P)x{D)+{pt+D+\+£f>l+->+]?jp{D)=0 ... (Equation 16) Therefore, parity P(D) is represented as shown in Equation 1 7 below. [17] l{D)=(tf+\+if,+---+£p)4D)+(jrf+n+lf+-+£fmHD) •■• (Equation 17) Here, DalX(D), ..., DanX(D) are known since they are input data, but Dp,P(D), ..., DPmP(D) are unknown values. Therefore, it is possible to insert "1" for a data related item in the upper trapezoidal matrix of parity check matrix H, but it is difficult to find a parity bit even if "1" is inserted for a parity related item. Thus, "1" is inserted for a data related item in the upper trapezoidal matrix of parity check matrix H. That is to say, when a check polynomial is represented by Equation 18, parity P(D) can be represented as shown in Equation 19 below, and parity P(D) can be found. [18] (o?+l+Zf'+—+rr)x(D)+{£?+D+l)F{D)=Q ... (Equation 18) (<*i, ..., a„<-l) [19] / Next, positions of added "l"s will be described in detail using FIG.10. In FIG.10, reference code 801 indicates a "1" relating to decoding of data Xj of point in time i, and reference code 802 indicates a "1" relating to decoding of parity Pi of point in time i. Dotted line 803 is a protograph involved in propagation of external information for data Xj and parity Pj of point in time i when one BP decoding operation is performed. That is to say, belief from point in time i-2 to point in time i + 2 is involved in propagation. Then boundary lines 804 and 805 are drawn in the same way as in Embodiment 1. Then "1" is added somewhere in area *806 so that belief before boundary line 804 is propagated to data Xi of point in time i. By this means, a probability that could not be obtained before adding "1," that is, probability other than from point in time i-2 to point in time i + 2, can be propagated. In order to propagate a new probability, it is necessary to add to area 806 in FIG.10. Here, the width from the rightmost "1" to the leftmost "1" in each row of parity check matrix H in FIG.10 is designated L. Thus far, a position at which "1" is added has been described in the column direction. Considering this in the row direction, in the parity check matrix in FIG.4, "1" is added at a position L-2 or more to the right of the rightmost "1." Also, when described in terms of a check polynomial, oi, ..., an should be set to -2 or below in Equation 1 8. This will be considered represented by a general expression. A general expression for a parity check polynomial of a convolutional code is represented as shown in Equation 6. When "1" is added as data to the upper trapezoidal matrix of parity check matrix H, a check polynomial is represented as shown in Equation 20 below. [20] {j^+lf+--'+l+Ifl+'-+lfn)x{D)+{jf+--+l)f(z))=0 ... (Equation 20) In this case, good received quality can be obtained by setting ai ctn to -K-l or below. However, good received quality can still be obtained if the condition that at least one of cti, ..., +1H^)=0 — (Equation 30) Also, a check polynomial for a termination bit at point in time f+2 is represented as shown in Equation 31 below. [31] i/f+£f+l+D'3MD)+itf+if^^+i)Hp)=0 •■• (Equation 31) Thus, a characteristic is that with termination bits, as shown in FIG.15, a position of an added "1" is shifted with time, >-and the order of a check polynomial is decreased with time (corresponding to reference code 1305 in FIG.15). In FIG.15, reference code 1304 indicates an example of the configuration of a termination bit protograph. In FIG.15, added "l"s are present in data and parity. Also, in order to prevent degradation of received quality of information bits, the order of a check polynomial is decreased so as to satisfy the condition of "2K + 1 or above" as described in Embodiment 1. Another characteristic of termination bits in FIG.15 is that, as the change from reference code 1305 to reference code 1306 shows in FIG.15, the number of "l"s additionally inserted in the parity check matrix is changed from two to one. By this means, the speed at which a trellis diagram stabilizes (converges) is improved. In this embodiment, an example has been described in which the number of "l"s added to a parity check matrix is two at the time of information bit transmission, and is then reduced to one at the time of termination bit transmission, but the present invention is not limited to this, and the same kind of effect can also be obtained, for example, by making the number of "l"s added to a parity check matrix M at the time of information bit transmission, and then reducing this number to N (where M>N) at the time of termination bit transmission. An advantage when "l"s are added to an upper trapezoidal matrix of a parity check matrix ("l"s indicated by reference code 1307 in FIG.15) will now be explained. For example, with data Xf.2 (1308) and parity Pf_2 (1309) of point in time f-2 in FIG.15, the influence of termination bit 1310 is experienced. As a result, the received quality of data Xf.2 (1308) of point in time f-2 is improved in the receiving apparatus. The same kind of effect can also be obtained in a similar way for data after point in time f-2. Thus, when "l"s are added to an upper trapezoidal matrix of a parity check matrix, the speed at which a trellis diagram stabilizes (converges) can be improved due to the above-described effect. In this embodiment, the order of a check polynomial is decreased in a regular manner (the order is decreased each time the ^number of rows increases by one), but the present invention can obtain the same kind of effect even if this decrease is not performed in a regular manner, and, for example, can obtain the same kind of effect if the order is decreased at intervals of several rows. (Embodiment 4) In Embodiment 1 and Embodiment 2, methods of designing an LDPC-CC from a (7, 5) convolutional code, that is, a feedback-type convolutional code, were described. In this embodiment, a case will be described in which the LDPC-CC design methods described in Embodiment 1 and Embodiment 2 are applied to a feed-forward-type convolutional code. Advantages of using a feed-forward-type convolutional code are that, for the same constraint length, a row weight and column weight are smaller and there are fewer loops of the length of 4 when drawing a Tanner graph in the case of a feed-forward-type convolutional code parity check matrix than in the case of a feedback-type convolutional code parity check matrix. A loop is a circular path that starts at a certain node and ends at that node, and if there are a large number of loops of the length of 4, received quality degrades (see Non-Patent Document 13). Consequently, when a feed-forward-type convolutional code is used, the possibility of received quality improving is high when BP decoding is performed. Thus, a characteristic of an LDPC-CC designed from a feed-forward-type convolutional code is having better performance than an LDPC-CC designed from a feedback-type convolutional code. In Non-Patent Document 12, a convolutional code that is of feed-forward type and a systematic code is described. Below, a case in which a (1, 1547) convolutional code is used will be described as an example. A check polynomial of a (1, 1547) convolutional code is represented as shown in the following equation. [32] {D"+Di+D'i+Di+D'+Dt + 1i)x(D)+piD)=o ... (Equation 3 2) Also, the following equation is used as an example of a parity check polynomial different from Equation 32 of a (1, 1547) ^convolutional code. [33] (D" + D,0+MD)+(DS + D* + D1 + D' + 1HD)=° — (Equation 33) Furthermore, P(D) given by the following equations will be considered as LDPC-CC check polynomials- (D«'+...+£)-+£>"+i>%,)Ar{D)+(D5+^+£)3+£)I+i)p(D)=o ■■■ (Equation 34) [35] (D-'+...+£>-+Z)%Z)«'+I)^0)+(C)'"+...+D*+^+Z)<+£,,+£)'+i|Ki>)=o »• (Equation 3 5) [36] {D"i^-+J)v+Du+D10+1+D^+-+DKk(o)+{Dt+Di+D3+D1+iyiD)=0 — (Equation 3 6) [37] ... (Equation 37) [38] b"+Z)'°-,-ik{D)+(D"+-+D*+Z)i + D4+Z)5+Z), + iH^)=o — (Equation 3 8) [39] (o"+D'°+i+Drt+-+D',to+(D',+-+jD*+Z)i+JD4+D3+i)1+iHZ))=0 - (Equation 3 9) [40] (DH+JDlo+i+£)'"+-+JDBk(o)+(D,+JD4+JD3+JD,+i)p(^)=o - (Equation 4 0) At this time, it is assumed that cti, ..., cee are integers of 15 or above, pi, ..., pf are integers of 15 or above, and YI, .... Yg are integers of -1 or below. At this time, as described in Embodiment 1 and Embodiment 2, at least one of alf ..., ae is set to an integer of 29 or above, at least one of Pi, ..., pf is set to an integer of 29 or above, and at least one of Yi, ..., yg is set to an integer of -15 or below. However, it is more effective if t">>^)^brf + Z)" + - + JE>ip»=o - (Equation 43) [44] {D°1+D°2+- + D°°)x(D)+{D* + D°1+- + D'r)pK(z>)=o - (Equation 44) [45] (DM + £>" + ••• + D'^HD)+{D" + DC1 + - + D°)pm(P)=* - (Equation 4 5) If data at point in time i is designated X;, parity relating to P(D) of Equation 42 at point in time i is designated Pj, and parity relating to Pn(D) of Equation 43 or Equation 44 or Equation 45 at point in time i is designated Pni, transmission sequence Wj can be represented by Wj = (Xi, Pj, Pnj). Also, the following equations will be considered as check polynomials relating to LDPC-CC X(D) and P(D) in the same way as in Embodiment 4. [46] (D«'+...+I)«+£)!*+£)1Vi)Ar(£.)+(Z)5+JD4+jDJ+£)I+i)p(^)=o - (Equation 46) [47] {D"1+..+D-+D"+Dt\i)x(D)+{pfl+-+Dff+Di+Dt+D^D^Moho - (Equation 47) [48] {Iy\...+D"+D"+D,\i+D»+...+D»)x(D)+y+Dt+D>+D]+i)liD)=0 - (Equation 48) [49] iD°<+...+D~+D"+D«+i+D>i+...+D")x(Dh(D>l+-+D*+Df+D'+Di+D'+iHD)=<> ... (Equation 49) [50] (D14+Z)'° + I)*(0)+{D"+ +D"+D*+D'+D'+D1+MD>O ••'• (Equation 5 0) [51] (D>\tf\l+D»+...+DK^(D)+{D»+...+Dx+D'+D\D>+D\1)P(D)=Q ... (Equation 51) [52] iDu+DM+i+Dr'+"+D*HD)+(D1+D<+Di+D,+iHz>)=o - (Equation 52) At this time, it is assumed that oi, ..., ae are integers of 15 or above, pi, ..., pf are integers of 15 or above, and yi, ..., yg are integers of -1 or below. At this time, as described in Embodiment 1 and Embodiment 2, at least one of cci, ..., ae is set to an integer of 29 or above, at least one of Pi, ..., Pf is set to an integer of 29 or above, and at least one of yi, ..., yg is set to -15 or below. However, it is more effective if ai, ..., ae are all set to integers of 29 or above, pi, ..., Pf are all set to integers of 29 or above, and yi, ..., yg are all set to -15 or below. Making such settings enables received quality (decoding performance) to be greatly improved. Then, a check polynomial relating to new parity sequence Pn(D) for LDPC-CC use is made one of Equation 43 through Equation 45. At this time, at least one of ai, ..., avis made an integer of 29 or above, or at least one of ai, ..., av is set to an integer of -15 or below. Also, at least one of b|, ..., bw is set to an integer of 29 or above. However, received quality (decoding performance) is greatly improved if ai, ..., av are all set to integers of 29 or above or are all set to integers of -15 or below. Also, received quality (decoding performance) is greatly improved if bi, ..., bw are all set to integers of 29 or above. Here, no restrictions are imposed on ci, ..., cy, but it is effective if at least one of ci, ..., cy is made an integer of 29 or above, and, in general, one ofcj, ..., cy is "0." A method of generating an LDPC-CC of a convolutional code of a coding rate of 1/3 from a convolutional code of a coding rate of 1/2 is summarized below. A convolutional code of a coding rate of 1/2 check polynomial is represented by the following equation, and the maximum value of + KX (the maximum order of a data X(D) term) and Ki (the maximum order of a parity P(D) term) is designated "-max- [53] ijf+- ■+\]x(D)+{jf+-+i)F{D)^o ... (Equation 53) Then X(D) and P(D) LDPC-CC check polynomials are created as in Embodiments 1 through 4 and another Embodiment 1. Following this, Pn(D) obtained from Equation 54 through Equation 56 is considered as a polynomial of a new parity sequence. [54] {D*+D'>+...+D-)x(D)+iD"+D» + ...+D>")p(D)+(D<>+D* + -+jy)Pt{p)^ ... (Equation 54) [55] k)aI + Z>'2 + - +ZrH>)+fc>CI + ir1 + - + IT)P„U>)=0 ... (Equation 55) [56] (D", + Z>M + - + £>'">(^) + (De, + Z>rt + - + Z>iP,(o)=0 - (Equation 5 6) At this time, at least one of ai, ..., av is made an integer of 2Kmax+l or above, or at least one of ai, ..., av is set to an integer of -Kmax-1 or below. Also, at least one ofbi, ..., bw is set to an integer of 2Kmax+l or above. However, received quality (decoding performance) is greatly improved if ai, ..., av are all set to integers of 2Kmax+l or above or are all set to integers of-Kra8x-l or below. Also, received quality (decoding performance) is greatly improved if bi, ..., bw are all set to integers of 2Kmax+l or above. Here, no restrictions are imposed on ci, ..., cy, but it is effective if at least one of ci, ..., cy is made an integer of 2Kmax+l or above, and, in general, one of ci, ..., cy is "0." As described above, according to this embodiment, provision is made for an LDPC-CC of a coding rate of 1/3 to be generated from a convolutional code of a coding rate of 1/2, using polynomial Pn(D) obtained from Equation 54 through Equation 56 as a new parity sequence for the coding rate of 1/3. In this case, by imposing restrictions such as described above on ai, ..., av and bi, ..., bw, the range in which belief is propagated can be extended without making changes to check polynomial P(D) of a coding rate of 1/2, and received quality (decoding performance) can be greatly improved. A description has been given above of a method of generating an LDPC-CC of a coding rate of 1/3 from a convolutional code of a coding rate of 1/2. With regard to generation of an LDPC-CC of a coding rate of 1/4 or below, an LDPC-CC of a coding rate of 1/4 or below can be generated if a new parity check polynomial is generated under the same kind of conditions as when generating an LDPC-CC of a coding rate of 1/3. (Embodiment 6) A sample variant of the method of generating an LDPC-CC from a convolutional code described in Embodiment 4 will be described in detail here. One of the following polynomials will be considered as a polynomial of an LDPC-CC check described in Embodiment 4. [57] {D°>+...+D«+D>\rf\l)x(D)+{tf+D\D>+D\{)p(D^Q ... (Equation 57) [58] (D-+...+^+^%D%i)^(D)+{D^ + ...+£)* + ^+I)« + Z)3+i)1 + 1jp(D)=0 (Equation 5 8) [59] [Dal+-+D"+Du+DK+i+Dr,+ "+D"HD)+{D,+D,+D'+Dx+MD)=° - (Equation 59) [60] {Da'+^Dx+D'4+D'°+i+Dr^^Dsk(DhiDfi'+-+Dv+D^D^D^Di^HD)=o ... (Equation 60) [61] (D"+D>\i)^D)+(D>>+...+D*+D>+D<+D>+Dt+i)p(D)=0 ... (Equation 61) [62] [Du+D"+i+Drl+-+D*)xfc)+{Dn+-+D*+Di+DA+Di+Di+Mp)=<> — (Equation 62) [63] \D"+I?+i+lf+-+D*)X(D)+(D>+D'+D'+D,+MD)=° - (Equation 63) [0135] At this time, it is assumed that cti, ..., ae are integers of 15 or above, pi, ..., (3f are integers of 15 or above, and Yi» ■•■» Yg are integers of -1 or below. At this time, as described iu£ Embodiment 1 and Embodiment 2, at least one of ai, ..., 2Kmax+l is added for X(D) or P(D). Provision has been made for an LDPC-CC to be configured using a parity check polynomial with an above-described configuration. Provision may also be made for a Dz term to be added to X(D) and P(D). Also, Equation 57 has been described as an example, but the present invention is not limited to this, and can also be implemented in a similar way with any of Equation 58 through Equation 63. By performing this kind of operation, a length-4C> loop or a short loop (for example, a length-6 loop) in a Tanner to. graph described in Non-Patent Document 13 can be eliminated, enabling received quality to be greatly improved. (Embodiment 7) In this embodiment, a configuration of a time varying LDPC-CC is described that allows puncturing to be performed easily and that has a simple encoder configuration. In particular, in this embodiment an LDPC-CC is described that enables data to be punctured periodically. With regard to LDPC codes, sufficient investigation has not so far been carried out into a puncturing method that punctures data periodically, and in particular, there has not been sufficient discussion of a method of performing puncturing easily. With an LDPC-CC according to this embodiment, data is not punctured randomly, but can be punctured periodically and in a regular manner, and degradation of received quality can be suppressed. Below, a method is described for configuring a time varying LDPC-CC for which the coding rate is R=l/2 capable of implementing the above. With a coding rate of 1/2, if a polynomial representation of an information sequence (data) is X(D), and a parity sequence polynomial representation is P(D), a parity check polynomial is represented as shown below. [64] (If+..+Ij»+l)x{D)+{jji+..+]f-+l)P(D)=Q ... (Equation 64) In Equation 64, it is assumed that al, a2, ..., an are integers of 1 or above (where al^a2^...#an, and al through an are all mutually different). Use of the notation "X#Y^...^Z" is assumed to express the fact that X, Y, ..., Z are all mutually different. Also, it is assumed that bl, b2, ..., bm are integers of 1 or above (where b 1 #b2#.. ./bm). Here, in order to make it possible to perform encoding easily, it is assumed that terms D°X(D) and D°P(D) (where D°=l) are present. Therefore, P(D) is represented as shown below. [65] ^)=tf+-+ZT'+te+(zyi+-+£fmto ••■ (Equation 65) As can be seen from Equation 65, since D°=l is present^ and terms of past parity, that is, bl, b2, ..., bm, are integers of 1 or above, parity P can be found sequentially. Next, a parity check polynomial of a coding rate of 1/2 different from Equation 64 is represented as shown below. [66] (0B+..-H2jw+i)x(z))+tf+..-H£)r,,+i)p(D)=o - (Equation 66) In Equation 66, it is assumed that Al, A2, ..., AN are integers of 1 or above (where A1 #A2^.../AN). Also, it is assumed that Bl, B2, ..., BM are integers of 1 or above (where B1^B2^,..^BM). Here, in order to make it possible to perform encoding easily, it is assumed that terms D°X(D) and D°P(D) (where D°=l) are present. Therefore, P(D) is represented as shown in Equation 67. [67] p(D)=yi+...+lf+l)x{D)+{lf+- •+/Jf^) - (Equation 67) Below, data X and parity P of point in time 2i are represented by X2i and P21 respectively, and data X and parity P of point in time 2i + l are represented by X21-H and P2i +1 respectively (where i is an integer). In this embodiment, an LDPC-CC of a time varying period of 2 is proposed whereby parity P2i of point in time 2i is calculated (encoded) using Equation 65 and parity P21 + 1 of point in time 2i+l is calculated (encoded) using Equation 67. In the same way as in the above embodiments, an advantage is that parity can easily be found sequentially. Below, a description will be given using Equation 68 and Equation 69 as examples of Equation 64 and Equation 66. [68] itf"+D"?+D"4+D"+M$+kr+D'"+]J34+lfs+Mt>)=<> - (Equation 68) [69] fo'\D,M+Zr+7J,35+ito+^ - (Equation 69) At this time, parity check matrix H can be represented as shown in FIG.17. In FIG.17, (Ha,11) is a part corresponding to Equation 68, and (He,11) is a part corresponding to Equation 69. Below, (Ha,11) and (He,11) are defined as sub-matrices. Thus, LDPC-CC parity check matrix H of a time varying^ period of 2 of this proposal can be defined by a first sub-matrix representing an a parity check polynomial of Equation 64, and a second sub-matrix representing an a parity check polynomial of Equation 66. Specifically, in parity check matrix H, a first sub-matrix and second sub-matrix are arranged alternately in the row direction. When the coding rate is 1/2, a configuration is used in which a sub-matrix is shifted two columns to the right between an i'th row and i+l'th row (see FIG.17). In the case of a time varying LDPC-CC of a time varying period of 2, an i'th row sub-matrix and an i + l'th row sub-matrix are different sub-matrices. That is to say, either sub-matrix (Ha,11) or sub-matrix (He,11) is a first sub-matrix, and the other is a second sub-matrix. If transmission vector u is represented as u = (X0, Po, X[, Pi, ..., Xk, Pk, ...)T> the relationship Hu = 0 holds true. This point is as explained in Embodiment 1 (see Equation 3). When BP decoding was performed using the parity check matrix in FIG.17, that is, a parity check matrix of a time varying period of 2, it was confirmed that data received quality improved greatly as compared with LDPC-CCs described in Embodiment 1 through Embodiment 6. A case has been described above in which the time varying period is 2, but the time varying period is not limited to 2. However, if the time varying period is too large, it is difficult to perform puncturing periodically, and it may be necessary to perform puncturing randomly, for example, with a resulting possibility of degradation of received quality. Below, the advantage of received quality being improved by decreasing the time varying period is explained. FIG.18 shows an example of a puncturing method in case of a time varying period of 1. In FIG.18, H is an LDPC-CC parity check matrix, and if a transmission sequence vector is designated v, the relationship in Equation 70 holds true. [70] Hv = 0 ... (Equation 70) Here, transmission sequence vector v = (vl, v2, v3, v4, v5, v6, ..., v2i, v2i + l, ...)T. ^> FIG.18 shows an example of a case in which a transmission sequence for which the coding rate of R=l/2 is punctured, giving the coding rate of R=3/4. When puncturing is performed periodically, a block period for selecting puncture bits is first set. FIG.18 shows an example in which the block period is made 6, and blocks are set as shown by the dotted lines (1602). Then two bits of the six bits forming one block are selected as puncture bits, and the selected two bits are set as non-transmitted bits. In FIG.18, circled bits 1601 are non-transmitted bits. In this way, a coding rate of 3/4 can be implemented. Therefore, the transmission data sequence becomes vl, v3, v4, v5, v7, v9, vlO, vll, vl3, vl5, vl6, vl7} vl9, v21, v22, v23, v25, ... A "1" inside a square in FIG. 18 has no initial log likelihood ratio at the time of reception due to puncturing, and therefore its log likelihood ratio is set to 0. In BP decoding, row computation and column computation are performed iteratively. Therefore, if two or more bits for which there is no initial log likelihood ratio (bits with a 0 log likelihood ratio) (lost bits) are included in the same row, log likelihood ratio updating is not performed by row computation in isolation for that row until the log likelihood ratio of a bit for which there is no initial log likelihood ratio (a bit with a 0 log likelihood ratio) is updated by column computation. That is to say, belief is not propagated by row computation in isolation, and iteration of row computation and column computation is necessary in order to propagate belief. Therefore, if there are many such rows, belief is not propagated in a case such as when there is a limit on the number of iteration processes in BP decoding, causing degradation of received quality. In the example shown in-FIG. 18, a bit corresponding to a 1 inside a square indicates an lost bit, and rows 1603 are rows for which belief is not propagated by row computation in isolation, that is, rows that cause degradation of received quality. Therefore, as a puncture bit (non-transmitted bit) decision method, that is, a puncturing pattern decision method, it is necessary to find a method whereby rows for which belief is not propagated in isolation due to puncturing are made as few ay. possible. Finding a puncture bit selection method is described below. When two bits of the six bits forming one block are selected as puncture bits, there are 3X2C2 2-bit selection methods. Of these, selection methods whereby cyclic shifting is performed within six bits of a block period can be regarded as identical. A supplementary explanation is given below using FIG.20A. As an example, FIG.20A shows six puncturing patterns when two of six bits are punctured consecutively. As shown in FIG.20A, puncturing patterns #1 through #3 become identical puncturing patterns by changing the block delimiter. Similarly, puncturing patterns #4 through #6 becomes identical puncturing patterns by changing the block delimiter. Thus, selection methods whereby cyclic shifting is performed within six bits of a block period can be regarded as identical. Therefore, there are 3x2C2*2/(3 x2) = 5 puncture bit selection methods. When one block is composed of L*k bits, and k bits of the L*k bits are punctured, the number of puncturing patterns found by means of Equation 71 exist. [71] I^X„C» - (Equation 71) The relationship between an encoding sequence and a puncturing pattern when focusing on one puncturing pattern is shown in FIG.20B. Although not shown, there are also puncture bits at Xi + 3 and Pi + 3. Consequently, as can be seen from FIG.20B, when two bits of six bits forming one block are punctured, existing check equation patterns for one puncturing pattern are (3><2)xl72. Similarly, when one block is composed of L*k bits, and k bits of the Lxk bits are punctured, the numbers of puncturing patterns found by means of Equation 72 exist for one puncturing pattern. [72] ixjtxi ... (Equation 72) 2 Therefore, in a puncturing pattern selection method, it is necessary to check whether or not belief is propagated in isolatio^^T" for the number of check equations (rows) found from Equation 73. [73] j^X3*2CV<3x2xi = l5 ... (Equation 73) From the above relationship, when making a coding rate of 3/4 from a code of a coding rate of 1/2, if k bits of an Lxk-bit block are punctured it is necessary to check whether or not belief is propagated in isolation for the number of check equations (rows) found from Equation 74. [74] —X, ^C^Lxkx- ••• (Equation 74) Then, if a good puncturing pattern cannot be found, it is necessary to increment L and k. Next, a case in which the time varying period is m will be considered. In this case, also, in the same way as when the time varying period is 1, m different check equations represented by Equation 64 are provided. Below, m check equations are designated "check equation #1, check equation #2, ..., check equation #m." Consider an LDPC-CC for which parity Pmi+i of point in time mi + 1 is found using "check equation #1," parity Pmj + 2 of point in time mi + 2 is found using "check equation #2," ..., and parity Pmi + m of point in time mi + m is found using "check equation #m." At this time, following the same line of thought as in the case of FIG.17, a parity check matrix is as shown in FIG.19. Thus, when making a coding rate of 3/4 from a code of a coding rate of 1/2, for a case in which two bits of a 6-bit block are punctured, for example, following the same line of thought as in the case of Equation 73, it is necessary to check whether or not belief is propagated in isolation for the number of check equations (rows) found from Equation 75. [75] ~rxi>llC2xLCM^'mi = 5xLCMi'i'm} — (Equation 75) In Equation 75, LCM{a,p} represents the least common multiple of natural number a and natural number p. As can be seen from Equation 75, as m increases, check 1 ~ equations that must be checked increase. Consequently, a puncturing method of periodically performing puncturing is not suitable, and, for example, a method of randomly puncturing is used, with a resultant possibility of received quality degrading. FIG.20C shows the number of parity check polynomials that must be checked when generating encoding sequences for which coding rates are R = 2/3, 3/4, and 5/6 by puncturing k bits of the Lxk bits by means of puncturing. Realistically, a time varying period enabling an optimal puncturing pattern to be found is between 2 and 10 or so. In particular, taking a time varying period enabling an optimal puncturing pattern to be found and an improvement in received quality into consideration, a time varying period of 2 is suitable. There is also an advantage of being able to configure an encoder/decoder extremely easily if the kind of check equations shown in Equation 64 and Equation 66 are repeated periodically with a time varying period of 2. In the case of time varying periods of 3, 4, 5, ..., 10, although an encoder/decoder configuration is slightly larger than when the time varying period is 2, as in the case of a time varying period of 2 a simple configuration can be employed when periodically repeating a plurality of parity check equations based on Equation 64 and Equation 66. When a time varying period is semi-infinite (an extremely long period), or an LDPC-CC is created from an LDPC-BC, the time varying period is generally extremely long, and therefore it is difficult to employ a method of periodically selecting puncture bits and to find an optimal puncturing pattern. Employing a method of randomly selecting puncture bits could be considered, for example, but there is a possibility of received quality degrading greatly when puncturing is performed. In Equations 64, 66, 68, and 69, a check polynomial can also be represented by multiplying both sides by Dn. In this embodiment, it has been assumed that terms D°X(D) and D°P(D) (where D°=l) are present in Equations 64, 66, 68, and 69. In this way, parity can be computed sequentially, with the^ result that the configuration of encoder becomes simple, and furthermore, in the case of a systematic code, if belief propagation to data of point in time i is considered, belief propagation to data can easily be understood if a D term is present in both data and parity, enabling code design to be carried out easily. If simplicity of code design is not taken into consideration, it is not necessary for a D°X(D) term to be present in Equations 64, 66, 68, and 69. FIG.21A shows an example of an LDPC-CC parity check matrix of a time varying period of 2. As shown in FIG.21A, in the case of a time varying period of 2, two parity check equations, parity check equation 1901 and parity check equation 1902, are used alternately. FIG.21B shows an example of an LDPC-CC parity check matrix of a time varying period of 4. As shown in FIG.21B, in the case of a time varying period of 4, four parity check equations, parity check equation 1901, parity check equation 1902, parity check equation 1903, and parity check equation 1904, are used alternately. As described above, according to this embodiment, provision is made for a parity sequence to be found by means of a -parity check matrix of a time varying period of 2 formed with parity check polynomial (64) and parity check polynomial (66) different from Equation 64. The time varying period is not limited to 2, and, for example, provision may also be made for a parity sequence to be found using a parity check matrix of a time varying period of 4 such as shown in FIG.2 1 B. However, if a time varying period of m is too large, it is difficult to perform puncturing periodically, and it may be necessary to perform puncturing randomly, for example, resulting in degradation of received quality. Realistically, a time varying period enabling an optimal puncturing pattern to be found is between 2 and 10 or so. In this case, received quality can be improved and puncturing can be performed periodically, enabling an LDPC-CC encoder to be configured easily. It has been confirmed that good received quality is obtained if the row weight in parity check matrix H, that is, the£> number of 1 elements among row elements of the parity check matrix, is between 7 and 12. Considering a code for which the minimum distance is excellent in a convolutional code, as described in Non-Patent Document 12, if the fact that row weight increases as constraint length increases — with, for example, the row weight being 14 in the case of a feedback convolutional code with a constraint length of 1 1 — is taken into consideration, the row weight between 7 and 12 can be considered to be a unique value of an LDPC-CC of this proposal. Also, if code design merit is taken into consideration, design is simplified if the same row weight is used for each row of an LDPC-CC parity check matrix. In the above description, a case in which the coding rate is 1/2 has been described, but the present invention is not limited to this, and a parity sequence can also be found using a parity check matrix of a time varying period of m and a coding rate other than 1/2, and the same kind of effect can also be obtained with a time varying period between 2 and 10 or so. In particular, if coding rates are R = 5/6, 7/8, or above, a puncturing pattern is selected so as to avoid a configuration comprising only rows including two or more lost bits in a LDPC-CC of a time varying period of 2 or a time varying period of m described in this embodiment. That is to say, selecting a puncturing pattern such that there is a row for which the number of lost bits is zero or one is important in obtaining good received quality when the coding rate is high, such as when the coding rates are R=5/6, 7/8, or above. (Embodiment 8) In this embodiment, a time varying LDPC-CC is described that uses a check equation such that "l"s are present in the upper trapezoidal matrix of the parity check matrix described in Embodiment 2, and that enables an encoder to be configured easily. A method is described below for configuring the above with the coding rate of R=l/2. With a coding rate of 1/2, if polynomial representation of an information sequence (data) is X(D), and a parity sequence polynomial representation is P(D), a parity check polynomial is represented as shown below. ([f+--+Dm+i+lJ1+--+lTH»)+(tfl+"+lT+$&)=Q •■• (Equation 76) In Equation 76, it is assumed that al, a2, ..., an are integers of 1 or above (where al/a2^...^an). Also, it is assumed that bl, b2, ..., bm are integers of 1 or above (where bl #b2#...^bm). Also, it is assumed that cl, c2, ..., cq are integers of -1 or below (where c l^c2^...^cq). Therefore, P(D) is represented as shown below, [77] p{D)={jf+-+jf+i+jf+-..+jf)x{D)+{jJl+. -+lf)p(D) ... (Equation 7 7) Parity P can be found sequentially in the same way as in Embodiment 2. Equation 78 and Equation 79 will be considered as parity check polynomials of a coding rate of 1/2 different from Equation 76. [77] {jf+..+If+i)x{D)+{if+-+£fM+i)F(£Jl=o ... (Equation 77) [79] (^+...+^+1+DV.+/)ce)^D)+(DB,+"+^+i)p(^=o - (Equation 79) In Equations 78 and 79, it is assumed that Al, A2, ..., AN are integers of 1 or above (where A 1^A2^...#AN). Also, it is assumed that Bl, B2, ..., BM are integers of 1 or above (where B1^B2^...^BM). Also, it is assumed that Cl, C2, ..., CQ are integers'of -1 or below (where cl^c2^...^cq). Therefore, P(D) is represented as shown below. [80] i{D)={lf+-+Lf^D)+{[f+-+jft)p{D) - (Equation 80) [81] Hoh{lf+--+DM+l+Da+^D^)+{jf+-+IJ'M)F{D) ... (Equation 81) Below, data X and parity P of point in time 2i are represented by X21 and P21 respectively, and data X and parity P of point in time 2i + l are represented by X21 + 1 and P2i +1 respectively (where i is an integer). At this time, an LDPC-CC of a time varying period of 2 for which parity P21 of point in time 2i is found using Equation 77 and parity P21+1 of point in time 2i+l is found using Equation 8 0r-or an LDPC-CC of a time varying period of 2 for which parity P2i of point in time 2i is found using Equation 77 and parity P2i + i of point in time 2i+l is found using Equation 81, is considered. An LDPC-CC of this kind provides the following advantages: • An encoder can be configured easily, and parity can be found sequentially. • Puncture bits can be set periodically. • Termination bit reduction and received quality improvement in puncturing upon termination can be expected. Next, an LDPC-CC for which the time varying period is m is considered. In the same way as when the time varying period is 2, "check equation #1" represented by Equation 78 is provided, and "check equation #2" through "check equation #m" represented by either Equation 78 or Equation 79 are provided. Data X and parity P of point in time mi+1 are represented by Xrai + i and Pmi+1 respectively, data X and parity P of point in time mi + 2 are represented by Xraj + 2 and Pmi + 2 respectively, ..., and data X and parity P of point in time mi + m are represented by Xmi + m and Pmi + m respectively (where i is an integer). Consider an LDPC-CC for which parity Pmi+i of point in time mi + 1 is found using "check equation #1," parity Pmi + 2 of point in time mi + 2 is found using "check equation #2," ..., and parity Pmi + m of point in time mi + m is found using "check equation #m." An LDPC-CC code of this kind provides the following advantages: • An encoder can be configured easily, and parity can be found sequentially. • Termination bit reduction and received quality improvement in puncturing upon termination can be expected As described above, according to this embodiment, provision is made for a parity sequence to be found by means of a parity check matrix of a time varying period of 2 formed with parity check polynomial (76) and parity check polynomial (78) different from Equation 76. Thus, when a check equation is used for which "l"s are present in an upper trapezoidal matrix of a parity check matrix, a time varying LDPC-CC encoder can be configured easily. The time variation period is not limited to 2. However, in the same way as in Embodiment 7, when a method is employed whereby puncturing is performed periodically, a time varying period enabling an optimal puncturing pattern to be found is realistically between 2 and 10 or so. In the case of time varying periods of 3, 4, 5, ..., 10, although an encoder/decoder configuration is slightly larger than when the time varying period is 2, as in the case of a time varying period of 2 a simple configuration can be employed when periodically repeating Equation 78 and Equation 79 check equations. In Equations 76, 78, and 79, a check polynomial can also be represented by multiplying both sides by Dn. In this embodiment, it has been assumed that terms D°X(D) and D°P(D) (where D°=l) are present in Equations 76, 78, and 79. In this way, parity can be computed sequentially, with the result that the configuration of the encoder becomes simple, and furthermore, in the case of a systematic code, if belief propagation to data of point in time i is considered, if a D° term is present in both data and parity, enabling code design to be carried out easily. If simplicity of code design is not taken into consideration, it is not necessary for a D°X(D) term to be present in Equations 76, 78, and 79. It has been confirmed that good received quality is obtained if the row weight in parity check matrix H, that is, the number of 1 elements among row elements of the parity check matrix, is between 7 and 12. Considering a code for which the minimum distance is excellent in a convolutional code, as described in Non-Patent Document 12, if the fact that row weight increases as the constraint length increases, with, for example, the row weight being 14 in the case of a feedback convolutional code with a constraint length of 11, is taken into consideration, making the row weight between 7 and 12 can be considered to be a unique feature of an LDPC-CC of this proposal. Also, if code design merit is taken into consideration, design is simplified if the same row weight is used for each row of an LDPC-CC parity check matrix. (Embodiment 9) In this embodiment, a detailed description will be given of a method of creating an LDPC-CC of a coding rate of 1/3 from an LDPC-CC of a coding rate of 1/2 (and a time varying period of m) described in Embodiment 7 and Embodiment 8. An LDPC-CC of a time varying period of 2 will be described as an example. Data X and parity P of point in time 2i are represented by X21 and P21 respectively, and data X and parity P of point in time 2i+l are represented by X2i + i and p2i + i respectively (where i is an integer). An LDPC-CC of a time varying period of 2 will be considered for which parity p2i of point in time 2i is found using Equation 64 and parity P2i +1 of point in time 2i+l is found using Equation 66. Here, a polynomial of a new parity sequence is designated Pn(D), and one of Equation 82 through Equation 84 will be considered. [82] b°l+Dal+-+Dm)x(»)+(Dbi+Dbl+-+D*kD)+to°l+Dc2+-+DiP,(t>)=<> ... (Equation 82) [83] {D« + ])« + ... + D-)x(p) + {Da + j)'1 + ... + D'')pm» + ...+ £)*>(£>)+(Dcl + Dcl+- + Z)*)p»=o "■ (Equation 84) It is assumed that al, a2, ..., ay are integers of 1 or above (where al^a2^...^ay). Also, it is assumed that bl, b2 bw are integers of 1 or above (where b 1 ^b2^.. .^bw), Also, it is assumed that cl, c2, ..., cy are integers of 1 or above (where c 1 ^c2^.. ,#cy). Then different check polynomials "check equation #1" and "check equation #2" configured by means of one of Equation 82 through Equation 84 are provided. Data X2i at point in time 2i and parity P2i at point in time 2i are found using Equation 64, and parity Pn(2i at point in time 2i (parity for a coding rate of 1/3) is found using "check equation #1." At this time, a transmission sequence can be represented as W2i = ( X2i, P2i, Pn2i). Similarly, data X2i + i at point in time 2i+l and parity P2i+i at point in time 2i+l are found using Equation 66, and parity^ Pn,2i + i at point in time 2i + l (parity for a coding rate of 1/3) is found using "check equation #2." At this time, a transmission sequence can be represented as W2i + i = ( X2i + i, P21 + 1, Pn2i + i). In general, one ofcl, ..., cy is "0." Terms corresponding respectively to X(D), P(D), and Pn(D) in Equations 82, 83 and 84 will be considered. A parity check matrix of a coding rate of 1/2 is configured from Equations 64 and 66. At this time, a plurality of terms (there are a plurality of "l"s in a parity check matrix) are present in each of X(D) and P(D). Then, if the coding rate is made 1/3, a check equation configuredby means of one of Equations 82, 83 and 84 is added. A column weight at this time will be considered. According to a check equation in the case of a coding rate of 1/2, there is a certain level of column weight in data X and parity P, for example, a weight of around 5. In this state, a data X and parity P column weight increases when a check equation configured by means of one of Equations 82, 83, and 84 is added in order to set a coding rate of 1/3, but an improvement in received quality cannot be expected when BP decoding is performed unless column weight is suppressed to a certain degree. Therefore, if a check equation configured by means of one of Equations 82, 83, and 84 is added when setting a coding rate of 1/3, the increase in data X and parity P column weight must be kept down to 1 or 2. Therefore, Equation 82 becomes one of Equations 85 through 88. T851 Also, Equation 84 becomes one of Equations 91 and 92. [91] fo" + Z)"H^)+(Dc, + £>c2 + - + D°)PM=* - (Equation 91) [92] foiK^)+tart + D£l+" + Zr)p>)=<> - (Equation 92) The relationship between the number of terms of a parity check polynomial of a coding rate of 1/2 and the number of terms of a parity check polynomial added in order to obtain a coding rate of 1/3 is explained below. Below, a case is described by way of example in which an LDPC-CC of a coding rate of 1/2 is created using a parity check polynomial represented by Equation 64 and Equation 66, and an LDPC-CC of a coding rate of 1/3 is created by adding a parity check polynomial represented by Equation 82 through Equation 92. Due to the presence of Dal through Dan and D°, the number of terms of X(D) in Equation 64 is n+1. Also, due to the presence of Dbl through Dbm and D°, the number of terms of P(D) in Equation 64 is m+1. Also, due to the presence of DA1 through DAN and D°, the number of terms of data X(D) in Equation 66 is N+1. Also, due to the presence of DB1 through DBM and D°, the number of terms of parity P(D) in Equation 66 is M+1. Also, due to the presence of Dcl through Dcy and D°, the number of terms of parity Pn(D) in Equations 82 through 92 is y+1. Here, the minimum value of the number of terms in Equation 64 and Equation 66, n+1, m+1, N+1, M+1, is designated Z. It has been confirmed that good received quality can be obtained if the relationship Y+1 and parity n-1 by P„-i,i- Then transmission vector w is represented as w = (Xi, Pi.i. P2,i9 •••) Pn-i,i) X2, Pi,2, P2,2, .-., Pn-1,2, ••■ Xi? Pt,i, P2,i, ..., Pn-i,i, ..-)• In this case, if a parity check matrix is designated H, above Equation 3 holds true. Here, in the same way as in Embodiment 1, probability propagation for data or (and) parity is taken into consideration, and "l"s are added to the parity check matrix. At this time, one or more of terms 2001_0, 2001_1, 2001_2, ..., 2001_n-l in FIG.22 are selected, and changed to terms 2002^0, 2002_1, 2002_2, ..., 2002_n-l. For example, if 2001_0 in FIG.22 is selected, 2001_0 is changed to 20020, and the other terms are not changed. Also, if 2001_0 and 2001_n-l in FIG.22 are selected, 2001_0 is changed to 20020, 2001_n-l is changed to 2002_n-l, and the other terms are not changed. Of course, terms 2001^0, 2001_1, 2001_2, ..., 2001_n-l in FIG.22 may all be changed. That is to say, the check polynomial becomes as shown in Equation 94 below. [94] (Dhl+Dh2+---+Dhsi+DKl+-" + l)X(D) + (Dhl+Db2+"-+Dhsl+DK1+-" + l)P1(D) + (Dhl+Dh2+"-+Dhs2+DK2+"-+l)P2(D)+--- + (Dhl+Dh2+"-+Dhsn",+0Kn"l+—+l)Pn_1(D)=0 ... (Equation 94) At this time, in FIG.22 and Equation 94, sx, si, S2, ..., sn-i are 1 or above, and hi, h2, ..., hsk>2Kraax+l is set (where k = x, 1, 2, ..., n-1). By this means, good received quality can be obtained. Good received quality can also be obtained if at least one of hi, h2, ..., hsk is 2Kmax+l or above. Next, a method of adding the coding rate is made 1/n and "l"s to an upper trapezoidal matrix of a parity check matrix will be described in detail. When the coding rate is 1/n, if polynomial representation of an information sequence (data) is X(D), polynomial representation of a parity 1 sequence is Pi(D), polynomial representation of a parity 2 sequence is P2(D), ..., and polynomial representation of a parity n-1 sequence is Pn-i(D), a parity check polynomial is represented as shown in Equation 32 below. Here, data at point in time i is represented by X;, parity 1 by Pi,i, parity 2 by P2,i, ■ ■•, and parity n-1 by P„-i,i. Then transmission vector w is represented as w={Xi, Pi.i, P2,i» •••, Pn-i,i, X2, Pi,2> P2,2, •••, Pn-1,2, ••., Xj, Pi.i, P2,i, ..., Pn-i,i, •••). In this case, if a parity check matrix is designated H, above Equation 3 holds true. Here, in the same way as in Embodiment 2, probability propagation for data or (and) parity is taken into consideration, and "l"s are added to the parity check matrix. At this time, term 2101_0 in FIG.23 is changed to terms 2102_0. That is to say, the check polynomial becomes as shown in Equation 95 below. [95] (Dhl+Dh2+-"+Dh"+DK*+-- + l)X(D) + (DKl+- + l)P1(D) + (DK2+...+1)p2(D)+... + (DKn-,+ ...+1)Pni(D)=0 (Equation 95) At this time, sx in FIG.23 is 1 or above, and hi, h2, ..., hsx<-Kmax~ 1 is set. By this means, good received quality can be obtained. Good received quality can also be obtained if at least one of hi, h2, ..., hsx is -Kmax-1 or below. As described above, a method described in Embodiment t^. and Embodiment 2 can be extended to a method of generating an LDPC-CC from a convolutional code of a coding rate of 1/n as described in this embodiment. Also, when an LDPC-CC is generated from a convolutional code of a coding rate other than the above, an LDPC-CC can be created in a similar way if a method described thus far is extended. In this embodiment, data can be obtained by performing BP decoding in a receiving apparatus even if transmission is performed after performing puncturing as described in Non-Patent Document 12 when transmitting data. At this time, since an LDPC-CC described in the embodiments is represented by a simple parity check matrix, data can be punctured more easily than in the case of an LDPC-BC. In this embodiment, an example has been described in which "l"s are added to an upper trapezoidal matrix of a parity check matrix for data, as shown in FIG.23, but the present invention is not limited to this, and, in combination with the case shown in FIG.22, "l"s may also be added to an approximate lower triangular matrix of a parity check matrix in addition to being added to an upper trapezoidal matrix of a parity check matrix. By this means, a further improvement in received quality can be expected. The check polynomial in this case is Equation 96 below. [96] (Dhl+Dh2+---+Dhs,+DKl+-" + l+DHI+DH2+-+DHt,t)X(D) + {Dhl+Dh2+-"+DhaI+Dltl+"- + l)pi(D) + (Dhl+Dh2+---+Dhs2+DIC2+—+l)P2(D)+-" + (Dhl+Dh2+—+Dhsn"1+DK,1"'+".-+l)Pn_t(D)=0 ... (Equation 96) The termination method when the coding rate is 1/2 described in Embodiment 3 can also be implemented in a similar way when the coding rate is 1/n as in this embodiment. (Another Embodiment 2) Here, a configuration of an encoder of the present invention will be described. FIG.24 shows an example of the configuration of Equation 15 encoder. In FIG.24, parity calculation section 2202 has data x (2201) (that is, X(D) of Equation 15), stored data 2205 (that is, DalX(D), Da2X(D), D9X(D), D6X(D), DSX(D) of Equation 15), and stored parity 2207 (that is, DplP(D), Dp2P(D), D9P(D), D8P(D), D3P(D), DP(D) of Equation 15) as input, performs Equation 15 computation, and outputs parity 2203 (that is, P(D) of Equation 15). Data storage section 2204 has data x (2201) as input, and stores its value. Similarly, parity storage section 2206 has parity 2203 as input, and stores its value. FIG.25 shows an example of the configuration of a encoder of Equation 19. Parts in FIG.25 that operate in the same way as in FIG.24 are assigned the same reference codes as in FIG.24. Storage section 2302 stores data 2301, and outputs stored data 2303 (that is, DalX(D), ..., DanX(D) of Equation 19). Data storage section 2204 outputs stored data 2205 (that is, D2X(D) of Equation 19). Parity storage section 2206 outputs stored parity 2207 (that is, D2P(D), DP(D) of Equation 19). Parity calculation section 2202 has various signals as input, and calculates and outputs Equation 19 parity. As described above, an encoder can basically be configured by means of a shift register and exclusive OR. Next, sum-product decoding will be described as an example of a decoder algorithm. A sum-product decoding algorithm is as described below. Sum-Product Decoding Two-dimensional MxN matrix H={Hmn} is assumed to be a parity check matrix of an LDPC code that is a decoding object. Subsets A(m), B(n) of set [1, N] = {1, 2, .... N} are defined as shown in Equations 97 and 98 below. [97] A(m)*{n:H^i) ■■■ (Equation 97) [98] 5(n) = »+i)x(D)+(E/n+■ ■ ■+D^+MD)+iprl+- • '+lfA)Pnip) = 0 ... (Equation 117) In Equation 117, it is assumed that al, a2, ..., a© are integers other th.an 0 (where al# a2#...#a). Also, it is assumed that pi, P2, ..., P£ are integers of 1 or above (where pi^p2^...#P£). Furthermore, it [s assumed that yl, y2, ..., yX are integers of 1 or above (where y 1 ^y2^...^yX). Then P(D) of point in time 2i+l is found using the irelational equation in Equation 117. At this time, P(D) can be found sequentially. Next, Equation 118 is considered as a parity check polynomial. ,[118] (^+...+^+i)^D)+(zyn+-+iy^Kz))+(DG,+--+i)GA+i)pn(^)=o ... (Equation 118) In Equation 118, it is assumed that El, E2 EQ are integers other than 0 (where El ^E2#...^EO). Also, it is assumed that Fl, F2, ..., FZ are integers of 1 or above (where F1#F2^...^FZ). Furthermore, it is assumed that Gl, G2, ..., GA are integers of 1 or above (where Gl 7^G2^...^GA). Then Pn(D) of point in time 2i+l is found using the relational equation in Equation 118. At this time, Pn(D) can be found sequentially. Creating an LDPC-CC of a time varying period of 2 as described above provides an advantage of enabling an optimal puncturing pattern to be selected easily when a method of periodically selecting puncture bits is employed, in the same way as in Embodiment 7. If the time varying period is within 10, it is easy to employ a method of performing puncturing periodically and find an optimal puncturing pattern. Next, an LDPC-CC for which the time varying period is m is considered. In the case of a time varying period of m, m different check equations represented by Equation 115 are provided, and those m check equations are designated "check equation A#l, check equation A#2, ..., check equation A#m." Also, m different check equations represented by Equation 116 are provided, and those m check equations are designated "check equation B#l, check equation B#2 check equation B#m." Data X, parity P and parity Pn of point in time mi + 1 are represented by Xmi + ], Prai+1 and Pnmi + i respectively, data X, parity P and parity Pn of point in time mi + 2 are represented by Xmi + 2, Pmi + 2 and Pnmi + 2 respectively, ..., and data X, parity P and parity Pn of point in time mi + m are represented by Xmj + m, Pmj + m and Pnmj + n respectively (where i is an integer). Consider an LDPC-CC of a time varying period of m for which parity Pmi+i of point in time mi + 1 is found using "check equation A#l" and parity Pnmj + i is found using "check equation B#l," parity Pmi + 2 of point in time mi + 2 is found using "check ./equation A#2" and parity Pnmi + 2 is found using "check equation B#2," ..., and parity Pmi + m of point in time mi + m is found using "check equation A#m" and parity Pnmj + m is found using "check equation B#m" at this time. This kind of LDPC-CC code provides an advantage of enabling parity to be found sequentially, in addition to being a code offering good received quality. The coding rate is not limited to 1/3, and an LDPC-CC code of a coding rate of 1/3 or below can also be created in a similar way. (Another Embodiment 7) In this embodiment, a description will be given of a transmitting apparatus that executes puncturing suitable for a transmission codeword sequence obtained by LDPC-CC encoding, and such a puncturing method. FIG.34 shows a configuration of a time-invariant LDPC-CC parity check matrix used in this embodiment. Unlike FIG.l, FIG.34 shows the configuration of parity check matrix H, not parity check matrix H . If a transmission codeword vector is denoted by v, the relational equation Hv = 0 holds true. In the description of a puncturing method according to this embodiment, a problem when a general puncturing method is applied to above transmission codeword sequence v will first be explained. A general puncturing method is described in Non-Patent Document 12, for example. Below, a case in which an LDPC-CC is configured using a (177, 13 1) convolutional code with a coding rate of R=l/2 is described as an example. FIG.35 is a drawing for explaining a general puncturing method. In FIG.35, vijt and V2,t (where t=l, 2, ...) indicate transmission codeword sequence v. With a general puncturing method, transmission codeword sequence v is divided into a plurality of blocks, and transmission codeword bits are punctured by using the same puncturing on each block. FIG.35 shows how transmission codeword sequence v is divided into blocks at 6-bit intervals, and transmission codeword bits are punctured in a fixed proportion using the same puncturing pattern on all blocks. In FIG.35, circled bits indicate bits that are punctured (bits that are not transmitted), and V2,i, ^2,3, V2,4, *v2,6, V2.7. v2,9, v2,io, v2>i2, v2,i3, and v2,i5 are selected and punctured (made non-transmitted bits) so that the post-puncturing coding rate becomes 3/4 for all of blocks 1 through 5. Next, the effect on the receiving side (decoding side) will be considered when the kind of general puncturing shown in FIG.35 is executed on a transmission codeword sequence obtained by encoding using an LDPC-CC. Below, a case in which BP decoding is used on the receiving side (decoding side) will be considered. In BP decoding, decoding processing is performed based on an LDPC-CC parity check matrix. FIG.36 shows the correspondence between transmission codeword sequence v and LDPC-CC parity check matrix H. In FIG.36, circled bits are transmission codeword bits that are punctured by puncturing. As a result, bits corresponding to a 1 inside a square in parity check matrix H cease to be included in a transmission codeword sequence. As a result, when BP decoding is performed there is no initial log likelihood ratio for a bit corresponding to a 1 inside a square, and therefore the log likelihood ratio is set to 0. In BP decoding, row computation and column computation are performed iteratively. Therefore, if two or more bits for which there is no initial log likelihood ratio (bits with a 0 log likelihood ratio) (that is, bits corresponding to a 1 inside a square in FIG.36) are included in the same row, log likelihood ratio updating is not performed by row computation in isolation for that row until the log likelihood ratio of a bit for which there is no initial log likelihood ratio (a bit with a 0 log likelihood ratio) is updated by column computation. That is to say, belief is not propagated by row computation in isolation, and iteration of row computation and column computation is necessary in order to propagate belief. Therefore, if there are many such rows, belief is not propagated in a case such as when there is a limit on the number of iteration processes in BP decoding, causing degradation of received quality. In the example shown in FIG.36, rows 3410 are rows for which belief is not propagated by row computation in isolation, that is, rows that cause degradation of received quality. On the other hand, when a puncturing method according to this embodiment is used, the number of rows for which belief is ^not propagated by row computation in isolation can be reduced. In this embodiment, transmission codeword bit puncturing is performed, using a first puncturing pattern and a second puncturing pattern whereby more bits are punctured than with the first puncturing pattern, for each transmission codeword bit processing unit on the receiving side (decoding side). This will now be explained using FIG.37 and FIG.38. FIG.37 is a drawing for explaining a puncturing method according to this embodiment. As in FIG.35, vi>t and V2,t (where t=l, 2, ...) indicate transmission codeword sequence v, and a case is described below in which one block is composed of 6 bits in the same way as in FIG.35. Also, it is assumed that a transmission codeword bit processing unit on the receiving side (decoding side) comprises block 1 through block 5. The example shown in FIG.37 shows the way in which v2,i, v2>3, v2>4, v2>6, v2,7, v2?9, v2,io, v2,i2, v2,i3, and v2,i5 are punctured as a result of using a first puncturing pattern whereby puncturing is not performed for the first block, block 1, and using a second puncturing pattern whereby puncturing is performed for block 2 through block 5. Thus, in this embodiment, puncturing patterns having different coding rates are used, and a range in which few bits are punctured is provided within a transmission codeword bit processing unit. FIG.38 shows the correspondence between transmission codeword sequence v and LDPC-CC parity check matrix H in this case. In FIG.38, although three rows occur that include two or more Is inside a square in the same row, the number of such rows has been reduced compared with the case shown in FIG.36. This is due to the fact that puncturing is not executed on block 1. Thus, by providing a block on which puncturing is not performed, the number of rows causing degradation of received quality when BP decoding is performed can be reduced. As a result, in rows up to rows 3610 there is a log likelihood initially, belief is dependably propagated in BP decoding, and post-updating belief is propagated to rows 3610, enabling degradation of received quality to be suppressed. Thus, due to the characteristics of the structure of a convolutional code (LDPC-CC) parity check matrix, row reliabilities obtained by row ^^computations in isolation are propagated sequentially by performing iterative decoding a plurality of times, enabling degradation of received quality due to puncturing to be suppressed Also, since the number of rows for which belief is not propagated by row computation in isolation is reduced, the number of iterations necessary for belief propagation can be reduced. In the example shown in FIG.37, transmitted transmission codeword bits increase and transmission speed decreases due to the provision of a block that is not punctured. However, as long as provision is made for the relationship N< and a second puncturing pattern whereby more bits are punctured han with the first puncturing pattern. The first puncturing pattern and second puncturing pattern have different proportions of bits that are punctured. Puncturing section 3710 punctures a transmission codeword sequence using a puncturing pattern such as shown in FIG.40, for example. In FIG.40, (N + M) bits comprise a receiving-side (decoding-side) processing unit. First puncturing section 3711 performs puncturing on a transmission codeword sequence using a first puncturirig pattern. Second puncturing section 3712 performs puncturing on a transmission codeword sequence using a second puncturing pattern. When the puncturing pattern shown in FIG.40 is used, first puncturing section 3711 does not perform puncturing on an N-bit transmission codeword sequence from the start of a receiving-side (decoding-side) processing unit, and outputs a transmission codeword sequence input to first puncturing section 3711 to switching section 3713. Second puncturing section 3712 performs puncturing on a bit (N+l) through (N + M) transmission codeword sequence, and outputs a post-puncturing transmission codeword sequence to switching section 3713. Provision may also be made for first puncturing section 3711 and second puncturing section 3712 to determine whether or not to execute puncturing on a transmission codeword sequence based on a control signal from control information generation section 2730. According to a control signal from the control information generation section (not shown), switching section 3713 outputs either a transmission codeword sequence output from first puncturing section 3711, or a transmission codeword sequence output from second puncturing section 3712, to interleaving section 2530. The operation of transmitting apparatus 3700 configured as described above will now be explained, focusing mainly on puncturing processing by puncturing section 3710. Below, a case in which LDPC-CC encoding section 2510 executes LDPC-CC encoding using a (177, 131) convolutional code with a coding rate of R=l/2 is described as an example. In LDPC-CC encoding section 2510, LDPC-CC encoding ..processing is executed on transmission information sequence ut (where t=l, ..., n), and v = (vi)t, v2,t) is acquired. In the case of a systematic code, vi,t is transmission information sequence ut and v2,t is parity. Parity v2,t is found based on transmission information sequence vijt and a check equation of each row in FIG.38. Puncturing processing is executed on transmission codeword sequence v of the coding rate of R=l/2 by puncturing section 3710. For example, when the puncturing shown in FIG.37 is used, puncturing is not performed on block 1 by puncturing section 3710, but bits are punctured in a regular manner at predetermined intervals for block 2 through block 5. That is to say, bits V2,4 and v2,6 are punctured in block 2, bits V2,7 and V2,9 are punctured in block 3, bits V2,io and* V2,i2 are punctured in block 4, and bits v2,i3 and V2,is are punctured in block 5. In this way, a transmission codeword sequence with the coding rate of R = 3/4 is acquired for block 2 through block 5. A post-puncturing transmission codeword sequence is transmitted to the receiving side (decoding side) via interleaving section 2530 and modulation section 2540. At this time, when the puncturing pattern shown in FIG.37 is used, v2,4, v2,6, v2,7, v2j9, V2,io, V2,i2, V2,i3, and v2,i5 are not transmitted. Thus, when the puncturing pattern shown in FIG.37 is used, blocks for which puncturing is not performed occur at predetermined intervals. As shown in FIG.37, as a result of puncturing not being performed on block 1, V2,i and v2,3, which were not transmitted when the general puncturing method in FIG.35 was used, are transmitted. Consequently, rows for which belief is not propagated by row computation in isolation when using BP decoding are the three rows shown as rows 3610 in FIG.38. As can be seen by comparing FIG.35 and FIG.37, adding two transmission bits decreases the number of rows for which belief is not propagated by row computation in isolation from six to three. As a result, the number of rows for which there is a log likelihood initially increases, and initial belief is updated dependably by BP decoding, and furthermore that belief is propagated to rows 3610 in FIG.38. Subsequently, due to the characteristics of the structure of a convolutional code (LDPC-CC) parity check matrix, reliabilities present in large numbers at the start of the parity check matrix are propagated sequentially by performing iterative decoding a plurality of times, enabling degradation of received quality due to puncturing to be suppressed. In the example shown in FIG.37, the additional number of bits that come to be transmitted is only two, and therefore a decrease in transmission speed is small and degradation of received quality can be suppressed. The achievement of this effect is due to the characteristic of an LDPC-CC adopting a form in which places where a 1 is present are concentrated in a parallelogram-shaped range in a parity check matrix, as shown in FIG.45. Therefore, there is little possibility of being able to obtain the same kind of effect by application to the case of an LDPC-BC. Thus, by providing a block that is not punctured, the number of rows that exert an adverse effect when BP decoding is performed can be reduced. To consider transmission efficiency at this time, it is important that the relationship N<)=0 ■■■ (Equation 119) Here, a parity check polynomial of Equation 120 satisfying Equation 119 will be considered. [120] [pn + £fi + ... + £r + l)x(D) . i \\\ ■■• (Equation 120) + (D61 + Eh + ■ ■■ + Ef■+lyip) = 0 In Equation 120, ai (where i = l, 2, ..., r) is a non-zero integer, and bj (where j = l, 2, ..., s) is an integer of 1 or above. A code defined by a parity check matrix based on a parity check polynomial of Equation 120 is called a time-invariant LDPC-CC here. Here, m different parity check polynomials based on Equation 120 are provided (where m is an integer of 2 or above). These parity check polynomials are represented as shown below. [121] A,(D)X{D)+B,{P)P(P)*=0 ... (Equation 121) At this time, i = 0, 1, ..., m-1. Then information and parity at point in time j are represented by Xj and Pj, and Uj = (Xj, Pj). At this time, point in time j information and parity Xj and Pj satisfy a parity check polynomial of Equation 122. U22] Ai{D)x(D)+Bi!{D)p{D)=0 (k=j mod m) ... (Equation 122) Here, "j mod m" is a remainder after dividing j by m. A code defined by a parity check matrix based on a parity check polynomial of Equation 122 is called a time varying LDPC-CC here. At this time, a time-invariant LDPC-CC defined by a parity check polynomial of Equation 121 and a time varying LDPC-CC defined by a parity check polynomial of Equation 122 have a characteristic of enabling parity easily to be found sequentially by means of a register and exclusive OR. In decoding, parity check matrix H is created from Equation 121 in the case of a time-invariant LDPC-CC and Equation 122 in the case of a time varying LDPC-CC, and if vector u = (uo, ui, ..., Ui, ...), the following relational equation holds true. [123] /4i=0... (Equation 123) Then, based on the relational equation in Equation 123, BP decoding is performed and a data sequence is obtained. (Specification or proposal) An example of content when a specification or proposal is created is shown below. 1. Use of LDPC-CC (Low-Density Parity-Check Convolutional Codes) that are error correction codes corresponding to a plurality of coding rates is proposed as an FEC (Forward Error Correction) Scheme. LDPC-CC are error correction code defined by a low-density parity parity check matrix, and constitute a code class having correction capability approaching the Shannon Limit, in the same way as a CTC (Convolutional Turbo Code) and LDPC-BC (Block Code) (see Non-Patent Document 12 and Non-Patent Document 15). An LDPC-CC has the following advantages over a CTC. (1) Interleaver is not necessary in encoder • Encoder can be configured using only shift registers and adders. • Information sequence length is not limited to interleaver length, enabling encoding of an information sequence of any length. (2) Sum-product decoding allowing parallel processing can be used for decoding algorithm, enabling processing delay to be reduced compared with CTC decoding requiring serial processing. Also, there are the following advantages compared with an LDPC-BC standardized by IEEE802.11n or the like. (3) Information sequence length is not limited to parity check matrix block length, enabling encoding of an information sequence of any length. (4) Encoding can be implemented using computation scale proportional to memory length (constraint length), making the configuration of an encoder simpler (memory length < information sequence length) than with LDPC-BC requiring computation scale proportional to information sequence length. (5) Decoding processing delay can be reduced by applying decoding algorithm using LDPC-CC-specific parity check matrix structure. 2. 2-1. FEC Encoding FIG.46 is a block diagram of an error correction encoding method (FEC scheme). The error correction encoding method comprises an LDPC-CC encoder and a puncturer. The length of payload data to be encoded is k bits, and the length of codeword data obtained after encoding is n bits. 2-2. LDPC-CC Encoding Payload data is encoded by the LDPC-CC encoder. FIG.47 shows the configuration of the LDPC-CC encoder. The LDPC-CC encoder outputs k systematic bits and k parity bits for k-bit payload data. Coding rate R of the LDPC-CC encoder is 1/2. The LDPC convolutional encoding process is as shown below. (1) Input comprising k information bits is divided into two. One is output as k systematic bits, and one is input to a constituent encoder. (2) The constituent encoder performs encoding processing on the k information bits, and outputs k parity bits. The LDPC-CC encoder outputs code bits two at a time in the following order: {dl,pl}, {d2,p2}, {d3,p3}, ..., {dk,pk}. The LDPC-CC is defined by a parity parity check matrix provided by Equation 124. ... (Equation 124) Parity check matrix H is a k><2k matrix. Each column of parity check matrix H correspond to systematic bits (dl, ..., dk) and parity bits (pi, ..., pk) in the order dl, pi, d2, p2, ... dt, pt, ..., dk, pk. M is the LDPC-CC memory length. Each row of parity check matrix H represents a parity check polynomial. Here, hd(,^(t) (where i = 0, ..., M) represents a weight (1 or 0) of a systematic bit in the t'th parity check polynomial, and hp(l)(t) (where i = 0, ..., M) represents a weight (1 or 0) of a parity bit in the t'th parity check polynomial. In parity check matrix H, all elements other than hJ)(0/»w i=0 i=The initial state of the LDPC-CC encoder is an all-zero state. That is to say, the initial state is as represented by Equation 130 below. 4 3 0] d =0 rt t^O... (Equation 130) pt=0 An LDPC-CC supports encoding of Information Bits of arbitrary length k with the same encoder configuration. Also, an LDPC-CC supports a plurality of memory lengths. 3. Encoding Termination In order to uniquely set the state of an LDPC-CC encoder at the time of encoding termination, termination is necessary. Termination is performed by means of zero-taiNng. Zero-tailing is implemented by performing LDPC-CC Encoding of tail-bits comprising 0 bits equivalent in number to memory length M. When termination is being performed, tail bits are a bit sequence known on the receiving side and therefore are not transmitted included in systematic bits, and only M parity bits obtained when tail bits were encoded are transmitted. 4. Puncturing Puncturing is processing that punctures (discards) a number of systematic bits and/or parity bits from LDPC-CC encoder output in order to obtain a code of a coding rate higher than 1/2 with a single encoder configuration. Coding rates supported by puncturing are shown in Table 1. Coding rates that should be supported are 1/2, 1/3, and 3/4, while coding rates of 4/5 and 5/6 are optional. Table 1] The following code rates shall be supported: 1/2, 2/3, 3/4 The following code rates are optional: 4/5, 5/6 Table 2 shows puncturing patterns used with the coding rates in Table 1. In the puncturing pattern column, d and p represent systematic bits and parity bits respectively, and when a value in a pattern is 0, that bit is punctured. LPunc represents the length of a puncturing pattern. Regular rotated puncturing is used for puncturing. Systematic bits and parity bits are delimited at Lpunc-bit intervals, and puncturing is performed in a regular manner in accordance with a puncturing pattern shown in Table 2. In the case of coding :-ates of 3/4, 4/5, and 5/6, systematic bits are also punctured, and the resulting code is a non-systematic code. [Table 2] Mandatory Rates Optional Rates Code Rate Puncturing Pattern LpuNC Code Rate Puncturing Pattern LPUNC 1/2 d: 1 p: 1 1 4/5 d:l00001011111 p:111011110100 12 2/3 d: 11 p: 01 2 5/6 d: 10101 p: 10101 5 3/4 d: 111010 p: 100111 6 5. The use of an LDPC-CC as an FEC scheme has been proposed above. An LDPC-CC encoder configuration, polynomials, and puncturing patterns have been shown, and the ability to use these as an FEC scheme has been shown. 6. 6-1. Example of LDPC-CC encoder LDPC-CC encoding can be implemented by any encoder that implements Equation 129. The configuration shown in FIG.48 is shown in Non-Patent Document 12 as an example of an LDPC-CC encoder. As shown in FIG.48, an LDPC-CC encoder comprises Ml shift registers storing ut, M2 shift registers storing pt, a weight controller that outputs weights in accordance with the order of hd(,)(t) and hp(l)(t) of each column of parity check matrix H, and a modulo 2 adder. Through the employment of this kind of configuration, the LDPC-CC encoder performs encoding processing of an LDPC-CC in accordance with Equation 125. As shown in FIG.48, an LDPC-CC encoder can be configured by means of shift registers, an adder, and a weight controller alone. (Another Embodiment 8) In this embodiment, a method will be described whereby the method of creating a time varying LDPC-CC of a coding rate of 1/2 described in Embodiment 7 is extended, and a time varying LDPC-CC of a coding rate greater than a coding rate of 1/2 is created. Below, a method of creating a time varying LDPC-CC of a coding rate of 3/4 or suchlike will be described as an example. Data XI, data X2, data X3, and parity P of point in time 2i are represented by Xi>2i, X2,i\, X3,2i, and P2i respectively, and data XI, data X2, data X3, and parity P of point in time 2i + l are wf^.fM.V^ by Xit2i+i, X2,2i+t, X3i2i+i, and P2i+i respectiveiy (where i is an integer). Here, a polynomial of data XI is designated Xl(D), a polynomial of data X2 is designated X2(D), a polynomial of data X3 is designated X3(D), and a polynomial of parity P is designated P(D), and the parity check polynomial below is considered. [131] In Equation 131, it is assumed that al, a2 ar are integers other than 0 (where al#a2^...^ar). Also, it is assumed that bl, b2, ..., bs are integers other than 0 (where bl^b2^...^bs). Furthermore, it is assumed that cl, c2, ..., cv are integers other than 0 (where cl #c2#...#cv). Moreover, it is assumed that el, e2, ..., ew are integers of 1 or above (where e 1/e2#...#ew). Then P(D) of point in time 2i is found using the relational equation in Equation 131. At this time, P(D) can be found sequentially. Next, Equation 132 is considered as a parity check polynomial. [132] In Equation 132, it is assumed that Al, A2, ..., AR are integers other than 0 (where Al #A2^...^AR). Also, it is assumed that Bl, B2, .,., BS are integers other than 0 (where B1#B2#...#BS). Furthermore, it is assumed that Cl, C2, ..., CV are integers other than 0 (where C1#C2#...#CV). Moreover, it is assumed that El, E2, ..., EW are integers of 1 or above (where E1#E2#...#EW). Then P(D) of point in time 2i + l is found using the relational equation in Equation 132. At this time, P(D) can be „c9und sequentially. • ■ Creating an LDPC-CC of a time varying period of 2 as described above provides an advantage of enabling an optimal puncturing pattern to be selected easily when a method of periodically selecting puncture bits is employed, in the same way as in Embodiment 7. If the time varying period is within 10, it is easy to employ a method of performing puncturing periodically and find an optimal puncturing pattern. Next, an LDPC-CC for which the time varying period is m (where m is an integer > 2) will be considered. In the case of a time varying period of m, m different check equations represented by Equation 131 are provided, and those m check equations are designated "check equation #1, check equation #2, ..., check equation #m." Then data XI, data X2, data X3, and parity P of point in time mi + 1 are represented by Xi>mi + i, X2)mi + i, X3>mi + i, and Pmj+i respectively, data XI, data X2, data X3, and parity P of point in time mi + 2 are represented by Xi ,mi + 2» X2,mi + 2> X3fmi + 2j and Pmi + 2 respectively, and data XI, data X2, data X3, and parity P of point in time mi + m are represented by Xi>mi + m, X2,mi + m, X3,mi+m, and Pmi + m respectively (where i is an integer). Consider an LDPC-CC of a time varying period of m for which parity Pmi + i of point in time mi+1 is found using "check equation #1," parity Pmj + 2 of point in time mi + 2 is found using "check equation #2," and parity Pmi + m of point in time mi + m is found using "check equation #m" at this time. This kind of LDPC-CC code provides an advantage of enabling parity to be found sequentially, in addition to being a code offering good received quality. In the above description, a time varying LDPC-CC based on Equation 131 and Equation 132 has been described, but an LDPC-CC of a time varying period of 2 or time varying period of m can also be formed using Equation 133 instead of Equation 131, or using Equation 134 instead of Equation 132. [133] The coding rate is not limited to 3/4, and an LDPC-CC code of a coding rate of n/n+1 can also be created in a similar way. For example, in the case of a time varying period of 2, data XI, data X2, data X3, ..., data Xn, and parity P of point in time 2i are represented by Xi,2i, X2,2i, X3,2i, ••-, Xn>2i, and P2i respectively, and data XI, data X2, data X3, ..., data Xn, and parity P of point in time 2i + l are represented by Xi,2i + i, X2,2i+i> X3(2i + i, ..., Xn,2i + i, and P21 + 1 respectively (where i is an integer). Here, a polynomial of data XI is designated X1(D), a polynomial of data X2 is designated X2(D), a polynomial of data X3 is designated X3(D), ..., a polynomial of data Xn is designated Xn(D), and a polynomial of parity P is designated P(D), and the parity check polynomial below is considered. [135] In Equation 135, it is assumed that ai.i, a^a, ..., ai>ri are integers other than 0 (where aiii^aii2^...^ai>ri). Also, it is assumed that a2,i, a2,2, •■-, 32,r2 are integers other than 0 (where a2,i#a2,2^...^a2,r2). The same applies to X3(D) through Xn-l(D). Furthermore, it is assumed that anji, a„,2> •■•> an,rn are integers other than 0 (where an,i^an,2^---^an,rn). Moreover, it is assumed that el, e2, ..., ew are integers of 1 or above (where el^e2^...^ew). Then P(D) of point in time 2i is found using the relational equation in Equation 135. At this time, P(D) can be found sequentially. Next, Equation 136 is considered as a parity check polynomial. [136] In Equation 136, it is assumed that Ai.i, AJj2, ..., AI,RI are integers other than 0 (where Ai,i#A]i2#...#Ai,Rl). Also, it is assumed that A2,i, A2,2} ..., A2jR2 are integers other than 0 (where A2>i#A2,2#t...#A2>R2). The same applies to X3(D) through Xn-l(D). Furthermore, it is assumed that An>i, An,2 An,Rn are integers other than 0 (where An>1#Anj2T*-.-#An,Rn). Moreover, it is assumed that El, E2, ..., EW are integers of 1 or above (where El#E2#...#Ew). Then P(D) of point in time 2i + l is found using the relational equation in Equation 136. At this time, P(D) can be found sequentially. Creating an LDPC-CC of a time varying period of 2 as described above provides an advantage of enabling an optimal puncturing pattern to be selected easily when a method of periodically selecting puncture bits are is employed, in the same way as in Embodiment 7. If the time varying period is within 10, it is easy to employ a method of performing puncturing periodically and find an optimal puncturing pattern. Next, an LDPC-CC for which the time varying period is m (where m is an integer > 2) will be considered. In the case of a time varying period of m, m different check equations represented by Equation 135 are provided, and those m check equations are designated "check equation #1, check equation #2, ..., check equation #m." Then data XI, data X2, data X3, ..., data Xn, and parity P of point in time mi + 1 are represented by Xi,mi + i, X2)I„j + i, Xa.mi+i, ••-, Xn>mi + i, and Pmi + i respectively, data XI, data X2, data X3, ..., data Xn, and parity P of point in time mi + 2 are represented by Xi,mi + 2j X2,mi + 2, X3>mi + 2, -.., Xn>rai + 2, and Pmi + 2 respectively, and data XI, data X2, data X3, data Xn, and parity P of point in time mi + m are represented by Xijmi + m, X2>mi + m, X3>mi + m, ..., Xnjmi + m, and Pmi + m respectively (where i is an integer). Consider an LDPC-CC of a time varying period of m for which parity Pmi+i of point in time mi + 1 is found using "check equation #1," parity Pmi + 2 of point in time mi + 2 is found using check equation #2," and parity Pmi + m of point in time mi + m is found using "check equation #m" at this time. This kind of LDPC-CC code provides an advantage of enabling parity to be found sequentially, in addition to being a code offering good received quality. In the above description, a time varying LDPC-CC based on Equation 135 and Equation 136 has been described, but an LDPC-CC of a time varying period of 2 or a time varying period of m can also be formed using Equation 137 instead of Equation 135, or using Equation 138 instead of Equation 136. Tl 371 (Another Embodiment 9) The reason why received quality degrades when a time varying LDPC-CC based on Equation 68 and Equation 69 described in Embodiment 7 is punctured will be described from the viewpoint of conditions for producing a parity check polynomial (hereinafter abbreviated to "polynomial") whereby bits corresponding to maximum orders of a plurality of parity check polynomials are not punctured at the same time. FIG.49 is a block diagram showing a main configuration of a transmitting apparatus according to this embodiment. In the description of this embodiment, configuration parts identical to those in FIG.39 are assigned the same reference codes as in FIG.39, and descriptions thereof are omitted. As compared with transmitting apparatus 3700 in FIG.39, transmitting apparatus 4700 in FIG.49 is equipped with LDPC-CC encoding section 4710 and puncturing section 4720 instead of LDPC-CC encoding section 2510 and puncturing section 3710. LDPC-CC encoding section 4710 generates parity bits for input information bits in accordance with parity check matrix H described later herein. LDPC-CC encoding section 4710 outputs codeword bits comprising information bits and parity bits to puncturing section 4720. Puncturing section 4720 punctures codeword bits. The puncturing pattern will be described later herein. Next, a case in which a parity check matrix used by LDPC-CC encoding section 4710 is configured by means of polynomials of Equation 139 and Equation 140 will be described as an example. [139] (D16 +Dm +D6 +1}X(D) + (D17 +Di +D4 +l)p(D) = 0... (Equation 13 9) [140] (Dv+D*+D*+l)x{D)+(D"+Dn+Ds+l)p(D) = 0... (Equation 14 0) Parameters of a parity check matrix in which above polynomials (139) and (140) are repeated alternately are shown in Table 3. [Table 3] Time varying period of T of check matrix T=2 Maximum order al of information bit of polynomial (139) al=16 Maximum order a2 of information bit of polynomial (140) a2=17 Maximum order pi of parity bit of Polynomial (139) pl=17 Maximum order p2 of parity bit of Polynomial (140) 132=19 Maximum order y of LDPC-CC = Max(al,a2,pi,p2) y=19 Second order Al of information bits of polynomial (139) Al=10 Second order A2 of information bits of polynomial (140) A2=8 Second order Bl of parity bit of polynomial (139) Bl=8 Second order B2 of parity bit of polynomial (140) B2=12 Pre-puncturing coding rate R R=l/2 FIG.50 shows the relationship between maximum orders al, a2, pi, P2 and second orders Al, A2, Bl, B2 of two polynomials. As shown in FIG.50, maximum orders al and a2 of information bits of the two polynomials are an even/odd pair. Below, these are represented as [al: even, a2: odd]. Also, second orders Al and A2 of information bits, maximum orders pi and p2 of parity bits, and second orders Bl and B2 of parity bits comprise even/even or odd/odd pairs. Below, these are represented as [Al: even, A2: even], [pi: odd, p2: odd], and [Bl: even, B2: even]. The relationships of these will be described using the parity check matrix in FIG.51. FIG.51 shows a parity check matrix of a time varying period of 2 configured using polynomials (139) and (140). In FIG.51, positions 4910-1 and 4910-2 indicate positions of bits corresponding to maximum orders al and a2 of information bits of the two polynomials; positions 4920-1 and 4920-2 indicate positions of bits corresponding to maximum orders pi and p2 of parity bits of the two polynomials; positions 4930-1 and 4930-2 indicate positions of bits corresponding to second orders Al and A2 of information bits of the two polynomials; and positions 4940-1 and 4940-2 indicate positions of bits corresponding to second orders Bl and B2 of parity bits of the two polynomials. In FIG.51, elements in shaded parts are all 1. As can be seen from positions 4910-1 and 4910-2 in FIG.51, when certain orders of the two polynomials are an even/odd pair (for example, [al: even, «2: odd]), those orders appear in the same column of the parity check matrix. Also, as can be seen from positions 4920-1 and 4920-2, 4930-1 and 4930-2, and 4940-1 and 4940-2 in FIG.51, when certain orders of the two polynomials are an even/even pair (for example, [Al: even, A2: even], [pi: odd, p2: odd], [Bl: even, B2: even]), those orders appear in different columns of the parity c;heck matrix. When maximum orders al and a2 of information bits are an even/odd pair ([al: even, a2: odd]) as in the case of polynomials (139) and (140), bits corresponding to the maximum orders appear in the same column. For instance, in the example shown in FIG.51, bits corresponding to maximum orders al and a2 of information bits are represented in information bit vi_i, vi,3, V1,5, v1,6, ... columns. Consequently, when these bits are punctured, bits corresponding to the maximum orders of the two polynomials are also punctured, and the polynomial constraint length is shortened, resulting in a decrease in error correction capability. A method of preventing such a decrease in error correction capability due to all bits corresponding to the maximum orders of the two polynomials being punctured is to use an LDPC-CC having polynomials such that the maximum orders of the # two polynomials are both even or are both odd. That is to say, provision is made for use of polynomials such that maximum orders al and a2 of information bits are either [al: even, a2: even] or [al: odd, a2: odd], and maximum orders pi and P2 of parity bits are either [pi: even, p2: even] or [pi: odd, P2: odd]. In other words, a characteristic of this embodiment is the use of an LDPC-CC having polynomials that satisfy Equation 141-1 for maximum orders al and a2 of information bits while also satisfying Equation 141-2 for maximum orders pi and P2 of parity bits. [141] al%2 = a2%2... (Equation 140-1) pl%2 = p2%2... (Equation 140-2) However, if maximum orders al and a2 of information bits have the same value, or if maximum orders pi and p2 of parity bits have the same value, bits corresponding to the maximum orders are punctured whatever kind of pattern is used. Therefore, it is necessary for these maximum orders to have different values and to form an even pair or an odd pair. That is to say, [al: even, a2: even, al#a2] or [al: odd, a2: odd, al#a2] is used for maximum orders al and a2 of information bits, and similarly, [pi: even, p2: even, pl#p2] or [pi: odd, P2: odd, pi#P2] is used for maximum orders pi and p2 of parity bits. Equations 141-1 and 141-2 show maximum order conditions for an LDPC-CC for which time varying period T = 2, that is, an LDPC-CC comprising two kinds of polynomial, but the time varying period is not limited to 2, and time varying period T may also be 3 or above. If time varying period T is 3 or above, an LDPC-CC should be used that has polynomials that satisfy Equation 142-1 for maximum orders al, a2, ..., at, ..., aT of information bits, while also satisfying Equation 142-2 for maximum orders pi, p2, ..., pt, ..., pT of parity bits. [142] al%T = a2%T=...=at%T=...=aT%T (al*a2*...#at*...*aT) ... (Equation 142-1) pi%T = P2%T=...=pt%T=... = pT%T (pl#p2#...7tpt#...#pT) ... (Equation 142-2) Next, to return to a case in which the time varying period is 2, a case will be described in which maximum orders [al, a2] and [pi, P2] of two polynomials satisfy one or both of Equations 141-1 and 141-2. Below, a case will be described as example in which Equation 141-1 is not satisfied and only Equation 141-2 is satisfied, using polynomials (139) and (140). In this case, bits corresponding to information bit related maximum orders al and r2). Furthermore, it is assumed that ajj, ai>2, ..., aiiri (where i = 3, ..., n-1) are integers (where ai(i#ai>2/...#airj). Moreover, it is assumed that a„,i, a„,2, ••-, an,m are integers (where an,i#an,2#...#an,riI). Also, it is assumed that el, e2, ..., ew are integers (where e l#e2#...#ew). Then it is assumed that P(D) of point in time 2i is found using the relational equation in Equation 148-1 for example. In Equation 148-2, it is assumed that Ai,i, Ai>2, ■-•, AI.RI are integers (where AI)I#AI>2#...#AIJRI). Also, it is assumed that A2,i, A2J2, ..., A2,R2 are integers (where A2>i#A2>2#...#A2,R2). Furthermore, it is assumed that Aj,i, AJJ2, ..,, A;,Ri (where i = 3, ..., n-1) are integers (where ALI#AJ##.-.#A#R;). Moreover, it is assumed that An,i, Anj2, ..., An,Rn are integers (where An,i#A„,2#.-.#An>Rn). Also, it is assumed that El, E2, ..., EW are integers (where E1#E2#...#EW). Then it is assumed that P(D) of point in time 2i+l is found using the relational equation in Equation 148-2 for example. In the case of a coding rate of n/n+1, also, as in the case of coding rates of 1/2 and 1/3, a parity check matrix should be used that is defined based on first parity check polynomial (148-1) whereby, in an LDPC-CC parity check polynomial of a time varying period of 2 represented by Equation 148-1, three or more even numbers or odd numbers are not included in [ai,i, aii2, ..., ai,rI] and the condition rl<4 is satisfied, or three or more even numbers or odd numbers are not included in [a*,], a;i2, ..., ai>ri] (where i = 2, 3, ..., n-1) and the condition ri<4 is satisfied, or three or more even numbers or odd numbers are not included in [an,i, anj2, ..., an,rn] and the condition rn<4 is satisfied# or three or more even numbers or odd numbers are not included in [el, e2, ..., ew] and the condition w<4 is satisfied; and second parity check polynomial (148-2) whereby, in a convolutional code parity check polynomial represented by Equation 148-2, three or more even numbers or odd numbers are not included in [Aj.i, A|>2, ..., AI,RI] and the condition Rl<4 is satisfied, or three or more even numbers or odd numbers are not included in [Aj,i, A1,2, ••-, AI,RJ] (where i = 2, 3, ..., n-1) and the condition Ri<4 is satisfied, or three or more even numbers or odd numbers are not included in [An,i, An>2, ..., A„,Rn] and the condition Rn<4 is satisfied, or three or more even numbers or odd numbers are not included in [El, E2, ..., EW] and the condition W<4 is satisfied. An LDPC-CC of a time varying period of 2 and a coding rate of n/n+1 with still better characteristics can be obtained by complying with the following condition: "An LDPC-CC of a time varying period of 2 is designed using a parity check matrix based on first parity check polynomial (148-1) satisfying [Condition #1] below and second parity check polynomial (148-2) satisfying [Condition #2] below in LDPC-CC parity check polynomials of a time varying period of 2 appearing in the form of Equation 148-1 and Equation 148-2." [Condition #1] In Equation 148-1, three or more even numbers or odd numbers are not included in [ai,i, ai,2, ..., ai,ri] and the condition rl<4 is satisfied; and three or more even numbers or odd numbers are not included in [a#i, a\,2, ■■■, ajrj] (where \~2, 3, ..., n-1) and the condition ri<4 is satisfied; and three or more even numbers or odd numbers are not included in [an,i, a„j2, ■■-, anjrn] and the condition rn<4 is satisfied; and three or more even numbers or odd numbers are not included in [el, e2, ..., ew] and the condition w<4 is satisfied. [Condition #2] Three or more even numbers or odd numbers are not included in [A1,1, A1,2, ..., A1,R1] and the condition Rl<4 is satisfied; and three or more even numbers or odd numbers are not included in [Ai(i, Ai)2, ..., Ai,Ri] (where i = 2, 3, ..., n-1) and the condition Ri<4 is satisfied; and three or more even numbers or odd numbers are not included in [An,1 An,2, ..., An,Rn] and the condition Rn<4 is satisfied; and three or more even numbers or odd numbers are not included in [El, E2, ..., EW] and the condition W<4 is satisfied. In the discussion of a loop 6 above, a condition has been that the number of each term is 4 or below. This is because if the number were 5 or above, three or more even numbers or three or more odd numbers would necessarily be present. An important theorem regarding a loop 6 will be described in detail in another Embodiment 14. Table 4 shows a list of Ak and Bk codes in a parity check polynomial of a time varying period of 2 and a coding rate of 1/2 based on Equation 122. Table 4 shows an example of an LDPC-CC of a time varying period of 2 and a coding rate of 1/2 that provides good reception performance in case where the maximum constraint length is 600 or below. With an LDPC-CC of a time varying period of 2 and a coding rate of 1/2, one important condition for an LDPC-CC that provides good received quality is that a column weight should be 10 or below in all columns of a parity check matrix. (Another Embodiment 10) In Embodiment 7, Embodiment 8, another Embodiment 5, another Embodiment 6, and another Embodiment 8, cases in which the time varying period of a time varying LDPC-CC is short, for example, between 2 and 10, have been described. Here, an LDPC-CC is described for which the time varying period is lengthened by applying an LDPC-CC of a time varying period of 2. A case in which the coding rate is 1/2 is described below as an example. Since a case in which the coding rate is 1/2 has been described in Embodiment 7, the following description is presented as a comparison with Embodiment 7. In Embodiment 7, LDPC-CCs with a time varying period between 2 and 10 or so were described. When parity check polynomials are generated randomly, although a code with good characteristics can easily be found in the case of an LDPC-CC of a time varying period of 2, it is difficult to find a code with good characteristics in the case of an LDPC-CC with a long time varying period. This is because, when parity check polynomials are generated randomly it is difficult to identify a combination of parity check polynomials capable of providing an LDPC-CC with good characteristics since the necessary number of parity check polynomials increases in proportion to the length of the time varying period. Thus, a method will be considered whereby an LDPC-CC of a time varying period of 2 is applied and an LDPC-CC with a long time varying period is generated. As explained in Embodiment 7, when the coding rate is 1/2, if a polynomial representation of an information sequence (data) is X(D), and a parity sequence polynomial representation is P(D), a parity check polynomial is represented as shown in Equation 64. In Equation 64, it is assumed that al, a2, .... an are integers other than 0 (where al#a2#...#an). Also, it is assumed that bl, b2, ..., bm are integers of 1 or above (where bl#b2#...#bm). Here, in order to make it possible to perform encoding easily, it is assumed that terms D°X(D) and D P(D) (where D°=l) are present. Therefore, P(D) is represented as shown in Equation 65. As can be seen from Equation 65, since D°=l is present and terms of past parity, that is, bl, b2, ..., bm, are integers of 1 or above, parity P can be found sequentially. Next, a parity check polynomial of a coding rate of 1/2 different from Equation 64 is represented as shown in Equation 66. In Equation 66, it is assumed that Al, A2, ..., AN are integers other than 0 (where A 1 4- A2#.. .# AN). Also, it is assumed that Bl, B2, ..., BM are integers of 1 or above (where B1#B2#...#BM). Here, in order to make it possible to perform encoding easily, it is assumed that terms D°X(D) and D°P(D) (where D°=l) are present. At this time, P(D) is represented as shown in Equation 67. Below, data X and parity P of point in time 2i are represented by X2i and P21 respectively, and data X and parity P of point in time 2i+l are represented by X21+1 and P2i+1 respectively (where i is an integer). In the case of an LDPC-CC of a time varying period of 2, parity P2i of point in time 2i is calculated using Equation 65 and parity P2i + 1 of point in time 2i + l is calculated using Equation 67. Here, an LDPC-CC of a time varying period of 2Z (where Z is an integer of 2 or above) will be considered. At this time, a parity check polynomial of Equation 65 and Z different parity check polynomials based on Equation 67, that is, (Z+l) different parity check polynomials, are provided. The Z different parity check polynomials based on Equation 67 are designated "check equation #0," "check equation #1," ..., "check equation #Z-1." Then parity of point in time j is found according to Case 1) or Case 2) below. Case 1) When j mod 2 (remainder after dividing j by 2) = 0 Parity of point in time j is found using Equation 65. Case 2) When j mod 2 (remainder after dividing j by 2) = 1 If the quotient when j is divided by 2 is designated k, and k = gZ + i (where g is an integer, and i = 0, 1, ..., Z-l), parity of point in time j is found using "check equation #i." In this way, an LDPC-CC of a time varying period of 2Z can be generated by means of (Z+l) different parity check polynomials. That is to say, a time varying LDPC-CC is formed by (Z+l) different parity check polynomials, a number smaller than a time varying period of 2Z. Although the use of Equation 64 and Equation 65 has been described above, the forms of parity check polynomials are not limited to these. Also, a case in which the coding rate is 1/2 has been described as an example, but this is not a limitation, and if the time varying period is other than 2, as described in another Embodiment 5, another Embodiment 6, another Embodiment 8, and so forth, an LDPC-CC of a time varying period of 2 can also be applied and an LDPC-CC of a long time varying period generated in the same way as in the case of a time varying period of 2. That is to say, Z different parity check polynomials "check equation #0," "check equation #1," ..., "check equation #Z-1," and check polynomial "polynomial #A" different from these "check equation #0," "check equation #1," ..., "check equation #Z-1," are provided, without limitations on the coding rate. Then parity of point in time j is found according to Case 1) or Case 2) below. Case 1) When j mod 2 (remainder after dividing j by 2) = 0 Parity of point in time j is found using "polynomial #A," Case 2) When j mod 2 (remainder after dividing j by 2) = 1 If the quotient when j is divided by 2 is designated k, and k=gZ+i (where g is an integer, and i = 0, 1 Z-l), parity of point in time j is found using "check equation #i." As described above, with a coding rate other than 1/2, also, a time varying LDPC-CC can be formed by means of fewer than parity check polynomials of a time varying period of 2Z. A time varying LDPC-CC can also be formed using fewer than parity check polynomials of a time varying period of 2Z by means of a method other than the above. For example, provision may also be made for a different parity check polynomials to be provided, and a time-variant-period-p (where p>a) LDPC-CC to be formed using a number of parity check polynomials from among the a parity check polynomials a plurality of times. However, when j mod 2 = 0 as in Case 1), there is a particular advantage of a parity check polynomial with good characteristics being easy to find if the same "polynomial #A" is always used to find parity of point in time j. (Another Embodiment 11) Here, a search creation method will be described for an LDPC-CC having confidentiality, applying an LDPC-CC described in another Embodiment 10. A case in which the coding rate is 1/2 is described below as an example. For example, a different parity check polynomials based on Equation 64 are provided. Then p (where a>P) parity check polynomials are extracted from the a parity check polynomials, and a time-variant-period-y (where y>p) LDPC-CC is created. At this time, parity of point in time j satisfying the condition j mod y - i is found using the same parity check polynomial. For example, if p polynomials are represented by "polynomial #1," "polynomial #2," ..."polynomial #p," and "polynomial #k" (where k=l, 2, ..., p) is used at least once with any of i = 0, 1, ..., y-1, since y>p all p parity check polynomials are used with i = 0, 1, ..., y-1. At this time, there are a plurality of methods of selecting P different polynomials and methods of setting time varying period y. Thus, it is difficult to correct errors unless the method of selecting p different polynomials and method of setting time varying period y decided on the transmitting side are known on the receiving side. Thus, confidential communication is proposed below whereby a transmitting apparatus includes a configuration that enables the above-described parity check polynomial selection method and time varying period to be changed, and a receiving apparatus takes the configuration of the encoder of the above transmitting apparatus as an encryption key. FIG.52 shows an example of a confidential communication system using the above-described method. A wireless communication system is described below as an example, but a confidential communication system is not limited to a wireless communication system. Wireless communication system 5000 in FIG.52 is equipped with transmitting apparatus 5010 and receiving apparatus 5020. Transmitting apparatus 5010 is equipped with LDPC-CC encoder 5012, modulation section 5014, antenna 5016, control section 5017, and key information generation section 5019. Control section 5017 selects P parity check polynomials. Parity check polynomials configure a parity check matrix used by LDPC-CC encoder 5012. Control section 5017 outputs encoding method related information including information on the selected p parity check polynomials to LDPC-CC encoder 5012. For example, control section 5017 stores a different parity check polynomials based on Equation 64, and extracts (selects) p (where p) parity check polynomials from the a parity check polynomials. Control section 5017 outputs information on the extracted (selected) p parity check polynomials to LDPC-CC encoder 5012 as encoding method related information 5018. Encoding method related information 5018 is shown below. For example, the a parity check polynomials are first numbered beforehand. Then provision is made for the numbers assigned to the a parity check polynomials to be known beforehand by both transmitting apparatus 5010 and receiving apparatus 5020. The numbers assigned to the extracted (selected) p parity check polynomials are used as encoding method related information 5018. Control section 5017 also sets time varying period y, and outputs information relating to a parity check polynomial used at point in time i from among the selected P parity check polynomials to LDPC-CC encoder 5012. LDPC-CC encoder 5012 has information 5011, and encoding method related information 5018 output from control section 5017, as input, and performs LDPC-CC encoding in accordance with the encoding method specified by information 5018. Specifically, LDPC-CC encoder 5012 finds parity of point in time j satisfying the condition j mod y = i using the same parity check polynomial. For example, the p parity check polynomials to be represented by "polynomial #1," "polynomial #2," ..."polynomial #p," and "polynomial #k" (where k=l, 2, ..., p) is used at least once with any of i = 0, 1, ..,, y-1. Thus, since y>P, all P parity check polynomials are used with i = 0, 1, ..., y-1. LDPC-CC encoder 5012 outputs post-encoding data 5013 to modulation section 5014. Modulation section 5014 has post-encoding data 5013 as input, executes modulation, band limiting, frequency conversion, amplification, and suchlike processing, and outputs obtained modulation signal 5015 to antenna 5016. Antenna 5016 emits modulation signal 5015 as a radio wave. Key information generation section 5019 has information 5018 relating to the encoding method in LDPC-CC encoder 5012 as input, generates key information with this information 5018 as a key, and reports the generated key information to receiving apparatus 5020 using a communication means of some kind. When numbering of a parity check polynomials is executed beforehand, for example, as described above, numbers assigned to extracted (selected) p parity check polynomials may also be used as keys. That is to say, key information generation section 5019 reports information relating to parity check polynomials used by LDPC-CC encoder 5012 to receiving apparatus 5020, Receiving apparatus 5020 is equipped with antenna 5021, demodulation section 5023, decoding section 5025, and key information acquisition section 5026. Key information acquisition section 5026 has key information transmitted from transmitting apparatus 5010 as input, and reproduces encoding method related information. For example, if numbers of parity check polynomials used by LDPC-CC encoder 5012 of transmitting apparatus 5010 are taken as keys, key information acquisition section 5026 reproduces the parity check polynomial numbers, and outputs encoding information 5027 including the obtained numbers to decoding section 5025. Demodulation section 5023 has received signal 5022 received by antenna 5021 as input, executes amplification, frequency conversion, quadrature demodulation, detection, and suchlike processing, and outputs log likelihood ratio 5024. Decoding section 5025 has encoding information 5027 as input and creates a parity check matrix based on the encoding method, and also has log likelihood ratio 5024 as input, executes decoding processing based on the parity check matrix, and outputs estimation information 5028. As described above, according to this embodiment transmitting apparatus 5010 is equipped with control section 5017 that selects parity check polynomials configuring a parity check matrix used by LDPC-CC encoder 5012 and outputs encoding method related information including information on the selected parity check polynomials to LDPC-CC encoder 5012, LDPC-CC encoder 5012 that performs encoding using the parity check polynomials selected by control section 5017, and key information generation section 5019 that reports encoding method related information including the parity check polynomials selected by control section 5017 to receiving apparatus 5020, and receiving apparatus 5020 performs decoding using parity check matrix H based on the encoding method related information reported from transmitting apparatus 5010. In this way, it is possible to implement confidential communication in which a method of selecting (J different parity check polynomials and a time varying period y setting method decided on the transmitting side are used as keys. A case has been described in which transmitting apparatus 5010 in FIG.52 generates an encryption key, that is, information for specifying parity check matrix H, but this embodiment is not limited to this, and provision may also be made for receiving apparatus 5020 to set an encryption key and report this to transmitting apparatus 5010. An example of a wireless communication system configuration in this case is shown in FIG.53. Wireless communication system 5100 in FIG.53 includes transmitting apparatus 5110 and receiving apparatus 5120. Configuration parts in FIG.53 identical to those in FIG.52 are assigned the same reference codes as in FIG.52, and descriptions thereof are omitted here. Receiving apparatus 5120 includes demodulation section 5023, decoding section 5025, control section 5121, and key information generation section 5123. In a similar way to control section 5017, control section 5121 generates encoding method related information 5122 and outputs generated encoding method related information 5122 to decoding section 5025. In a similar way to key information generation section 5019, key information generation section 5123 has encoding method related information 5122 as input, generates key information with this information 5122 as a key, and reports the generated key information to transmitting apparatus 5110 using a communication means of some kind. Transmitting apparatus 5110 includes LDPC-CC encoder 5012, puncturing/error adding section 5113, modulation section 5014, and key information acquisition section 5111. Key information acquisition section 5111 has key information reported from receiving apparatus 5120 as input, reproduces encoding method related information 5112, and outputs information 5112 to LDPC-CC encoder 5012. LDPC-CC encoder 5012 performs encoding based on encoding method related information 5112;. When an LDPC-CC is a systematic code, if the communication state is good, such as when the radio reception electric field intensity is high, for example, data (information) X can be obtained by any kind of receiving apparatus by extracting only a part corresponding to data (information) X without error correction (decoding) being performed on the receiving side. That is to say, it may be possible to receive another person's information without permission. To avoid this, provision may be made for puncturing/error adding section 5113 to be provided in transmitting apparatus 5110 as shown in FIG.53, and for puncturing/error adding section 5113 to jjerform processing such as puncturing data (information) X or replacing some data with intentionally erroneous data. Providing puncturing/error adding section 5113 in this way makes it difficult for a receiving apparatus to obtain data (information) X unless it has a correct decoding function. In the above description, a case has been described in which a different parity check polynomials based on Equation 64 are provided, but this embodiment is not limited to the use of Equation 64, and another parity check polynomial may be used. (Time-invariant/time varying LDPC-CCs based on a convolutional code (of a coding rate of (n-1 )/n)(where n is a natural number)) An overview of time-invariant/time varying LDPC-CCs based on a convolutional code is given below. A parity check polynomial represented as shown in Equation 149 will be considered, with polynomial representations of coding rate of R=(n-l)/n information Xi, X2, ..., Xn-i as Xi(D), XzfD), ..., Xn-i(D), and polynomial representation of parity P as P(D). [149] [fpu+na\,2 + —+rfi\r\ + l)x\ {D)+(z**2,i + i?Z2,2 + • ■ •+Dflisi+\)x2 (D) + ...+(pan-U+Daa<2 + :+r)a»-i,™ + l)xr-i(D) — (Equation 149) + (ph+£p2 + •■ ■+jybs+})p(D) = 0 In Equation 149, at this time aPiP (where p=l, 2, ..., n-1 and q=l, 2, ..., rp) is, for example, a natural number, and satisfies the condition ap>i#ap>2#.• .#ap,rp. Also, bq (where q—1, 2, ..., s) is a natural number, and satisfies the condition b i/b2#.. .#bs. A code defined by a parity check matrix based on a parity check polynomial of Equation 149 at this time is called a time-invariant LDPC-CC here. Here, m different parity check polynomials based on Equation 149 are provided (where m is an integer of 2 or above). These parity check polynomials are represented as shown below. [150] AxM(D)Xx{D)+Ax7,i(D)x2{D)+- , , , , / \ / \ ■■• (Equation 150) + Axn-u {D)xn-i {D) + Bi (D)P{D) = 0 Here, i = 0, 1, ..., m-1 . Then information Xi, X2, ..., X„.i at point in time j is represented as Xij, X2J, ..., X„-i,j, parity P at point in time j is represented as Pj, and UJ = (XIJ, X2J, ..., Xn-i,j, Pj)T- At this time, point in time j information Xij, X2J, ..., Xn-i,j, and parity Pj satisfy a parity check polynomial of Equation 151. [151] Here, "j mod m" is a remainder after dividing j by m. A code defined by a parity check matrix based on a parity check polynomial of Equation 151 is called a time varying LDPC-CC here. At this time, a time-invariant LDPC-CC defined by a parity check polynomial of Equation 149 and a time varying LDPC-CC defined by a parity check polynomial of Equation 151 have a characteristic of enabling parity easily to be found sequentially by means of a register and exclusive OR. For example, the configuration of parity check matrix H of an LDPC-CC of a time varying period of 2 based on Equation 149 through Equation 151 with a coding rate of 2/3 is shown in FIG.54. Two different check polynomials of a time varying period of 2 based on Equation 151 are designed "check equation #1" and "check equation #2." In FIG.54, (Ha,111) is a part corresponding to "check equation #1," and (He,111) is a part corresponding to "check equation #2." Below, (Ha,111) and (He,111) are defined as sub-matrices. Thus, LDPC-CC parity check matrix H of a time varying period of 2 of this proposal can be defined by a first sub-matrix representing a "check equation #1" parity check polynomial, and a second sub-matrix representing a "check equation #2" parity check polynomial. Specifically, in parity check matrix H, a first sub-matrix and second sub-matrix are arranged alternately in the row direction. When the coding rate is 2/3, a configuration is used in which a sub-matrix is shifted three columns to the right between an i'th row and i + l?th row, as shown in FIG.54. In the case of a time varying LDpC-CC of a time varying period of 2, an i'th row sub-matrix and an i + l'th row sub-matrix are different sub-matrices. That is to say, either sub-matrix (Ha,111) or sub-matrix (He,111) is a first sub-matrix, and the other is a second sub-matrix. If transmission vector u is represented as u = (Xi>0, X2>o, Po, Xi,i, X2,i, Pi, ..., Xi>t, X2,k, Pk, ...)T> the relationship Hu = 0 holds true. This point is as explained in Embodiment 1 (see Equation 3). Next, an LDPC-CC for which the time varying period is m is considered in the case of a coding rate of 2/3. In the same way as when the time varying period is 2, m parity check polynomials represented by Equation 149 are provided. Then "check equation #1" represented by Equation 149 is provided. "Check equation #2" through "check equation #m" represented by Equation 149 are provided in a similar way. Data X and parity P of point in time mi + 1 are represented by Xm, + i and Pmi+i respectively, data X and parity P of point in time mi + 2 are represented by Xmi + 2 and Pmi + 2 respectively, ..., and data X and parity P of point in time mi + m are represented by Xmj + m and Pmi + m respectively (where i is an integer). Consider an LDPC-CC for which parity Pmi+1 of point in time mi+1 is found using "check equation #1," parity Pmi + 2 of point in time mi + 2 is found using "check equation #2," ..., and parity Pmi + m of point in time mi + m is found using "check equation #m." An LDPC-CC of this kind provides the following advantages: • An encoder can be configured easily, and parity can be found sequentially. • Termination bit reduction and received quality improvement in puncturing upon termination can be expected. FIG.55A shows the configuration of an above-described an LDPC-CC parity check matrix of a coding rate of 2/3 and a time varying period of m. In FIG.55A, (Hi,111) is a part corresponding to "check equation #1," (H2,lll) is a part corresponding to "check equation #2," ..., and (Hm,lll) is a part corresponding to "check equation #m." Below, (Hi,111) is defined as a first sub-matrix, (H2,lll) is defined as a second sub-matrix, ..., and (Hm,lll) is defined as an m'th sub-matrix. Thus, LDPC-CC parity check matrix H of a time varying period of m of this proposal can be defined by a first sub-matrix representing a "check equation #1" parity check polynomial, a second sub-matrix representing a "check equation #2" parity check polynomial, ..., and an m'th sub-matrix representing a "check equation #m" parity check polynomial. Specifically, in parity check matrix H, a first sub-matrix through m'th sub-matrix are arranged periodically in the row direction (see FIG.55A). When the coding rate is 2/3, a configuration is used in which a sub-matrix is shifted three columns to the right between an i'th row and i+l'th row (see FIG.55A). If transmission vector u is represented as u = (Xi,o, X2,o, Po, Xi,i, X2,i, Pi,...,Xi,ic, X2,k, Pk,--.)T> the relationship Hu = 0 holds true. This point is as explained in Embodiment 1 (see Equation 3). In the above description, a case of a coding rate of 2/3 has been described as an example of a time-invariant/time varying LDPC-CC based on a convolutional code of a coding rate of (n-l)/n, but a time-invariant/time varying LDPC-CC parity parity check matrix of a convolutional code of a coding rate of (n-l)/n can be created by thinking in a similar way. That is to say, whereas, in the case of a coding rate of 2/3, in FIG.55A (Hi,111) is a part (first sub-matrix) corresponding to "check equation #1," (H2,lll) is a part (second sub-matrix) corresponding to "check equation #2," ..., and (Hm,lll) is a part (m'th sub-matrix) corresponding to "check equation #m," in the case of a coding rate of (n-l)/n the situation is as shown in FIG.55B. That is to say, a part (first sub-matrix) corresponding to "check equation #1" is represented by (Hi,ll...l), and a part (k'th sub-matrix) corresponding to "check equation #k" (where k = 2, 3, ..., m) is represented by (Hk, 1 1... 1). At this time, the number of "l"s of parts excluding Hk in the k'th sub-matrix is n. Also, in parity check matrix H, a configuration is used in which a sub-matrix is shifted n columns to the right between an i'th row and i+l'th row (see FIG.55B). If transmission vector u is represented as u=(X|io, #2,0 X,.](o, Po, Xi,i, X2,l, ...,Xn_iFi, Pj, ..., X#k, X2?k, •••» Xn-i,k, Pk, ■••) , the relationship Hu = 0 holds true. This point is as explained in Embodiment 1 (see Equation 3). Table 5 shows a list of Ak and Bk codes in a parity check polynomial of a time varying period of 2 and a coding rate of 1/2 based on Equation 122. Table 5 shows an example of LDPC-CCs of a time varying period of 2 and coding rates of 2/3, 3/4 and 5/6 that provide good reception performance in case where the (Another Embodiment 12) Here, the relationship between parity check polynomials and parity check matrix H will be described. Below, the case of a time varying period of 2 is described as an example. FIG.56A shows a "check equation #1" parity check polynomial used when finding parity of point in time 2i, and corresponding first sub-matrix Hi (5405). In first sub-matrix Hi (5405) shown in FIG.56A, dotted line 5400-1 indicates a boundary between point in time 2i and point in time 2i + l in parity check matrix H. Also, element 5401, the second element from dotted line 5400-1, corresponds to a "1" relating to data (information) of a parity check polynomial, and element 5402, the element immediately to the left of dotted line 5400-1, corresponds to a "1" relating to parity check polynomial parity. FIG.56B shows a parity check polynomial of "check equation #2" used when finding parity of point in time 2i, and corresponding second sub-matrix H2 (5406). In second sub-matrix H2 (5406) shown in FIG.56B, dotted line 5400-2 indicates a boundary between point in time 2i+l and point in time 2i + 2 in parity check matrix H. Also, element 5403, the second element from dotted line 500-2, corresponds to a "1" relating to data (information) of a parity check polynomial, and element 5404, the element immediately to the left of dotted line 500-2, corresponds to a "1" relating to parity check polynomial parity. FIG.57 shows LDPC-CC parity check matrix H of a coding rate of 1/2 and a time varying period of 2 configured by means of first sub-matrix Hi shown in FIG.56A and second sub-matrix H2 shown in FIG.56B. As can be seen from FIG.57, in the case of a coding rate of 1/2, a configuration is used whereby boundary 5400-1 between point in time 2i and point in time 2i + l of first sub-matrix Hi and boundary 5400-2 between point in time 2i+l and point in time 2i + 2 of second sub-matrix H2 are shifted two columns to the right between the 2i'th row and the (2i + l)'th row. Also, a configuration is used whereby boundary 5400-2 between point in time 2i+l and point in time 2i + 2 of second sub-matrix H2 and dotted line corresponding to a boundary between point in time 2i and point in time 2i + l of first sub-matrix Hi (boundary between point in time 2i + 2 and point in time 2i + 3) 5400-1 are shifted two columns to the right between the (2i+l)'th row and the (2i + 2)'th row. The above-described relationship between parity check polynomials and parity check matrix H is also similar for an LDPC-CC of a time varying period of 2 or time varying period of m parity check matrix described in the above embodiments and another embodiments. Transmission sequence u is represented as u = (X0, Po, Xi, Pi, ..., Xi, Pi, ,..)T, where Xi is information and Pj is parity. Transmission sequence u is a systematic code. In this case, first sub-matrix Hi in FIG.56A satisfies the condition X2i-3 + X2i + P2i-5 + P2i-3 + P2i = 0. Similarly, second sub-matrix H2 in FIG.56B satisfies the condition X(2i + i)-4 + X(2i + i> + X(2i+t) + 5 + P(2i+I)-3 + P(2i + 1)-1 + P(2i+1)- 0. In the above description, the relationship between parity check polynomials and parity check matrix H has been described taking the case of a coding rate of 1/2 and time varying period of 2 as an example, but the relationship between parity check polynomials and parity check matrix H is not limited to a coding rate and time varying period. Below, a case in which the coding rate is 2/3 and the time varying period is 2 is described. FIG.58A shows a "check equation #1" parity check polynomial used when finding parity of point in time 2i, and corresponding first sub-matrix Hi (5604). In first sub-matrix Hi (5604) shown in FIG.58A, dotted line 5600-1 indicates a boundary between point in time 2i and point in time 2i+l in parity check matrix H. Also, element 5601, the third element from dotted line 5600-1, corresponds to a "1" relating to Xl(D), element 5602, the second element from dotted line 5600-1, corresponds to a "1" relating to X2(D), and element 5603, the element immediately to the left of dotted line 5600-1, corresponds to a "1" relating to P(D) parity. FIG.58B shows a parity check polynomial of "check equation #2" used when finding parity of point in time 2i+l, and corresponding second sub-matrix H2 (5608). In second sub-matrix H2 (5608) shown in FIG.58B, dotted line 5600-2 indicates a boundary between point in time 2i+l and point in time 2i + 2 in parity check matrix H. Also, element 5605, the third element from dotted line 5600-2, corresponds to a "1" relating to X1(D), element 5606, the second element from dotted line 5600-2, corresponds to a "1" relating to X2(D), and element 5607, the element immediately to the left of dotted line 5600-2, corresponds to a "1" relating to P(D) parity. FIG.59 shows LDPC-CC parity check matrix H of a coding rate of 2/3 and a time varying period of 2 configured by means of first sub-matrix Hi shown in FIG.58A and second sub-matrix H2 shown in FIG.58B. As can be seen from FIG.59, in the case of a coding rate of 2/3, a configuration is used whereby boundary 5600-1 between point in time 2i and point in time 2i+l of first sub-matrix Hi and boundary 5600-2 between point in time 2i+l and point in time 2f + 2 of second sub-matrix H2 are shifted three columns to the right between the 2i'th row and the (2i + l)'th row. Also, a configuration is used whereby boundary 5600-2 between point in time 2i + l and point in time 2i + 2 of second sub-matrix H2 and dotted line corresponding to a boundary between point in time 2i and point in time 2i+l of first sub-matrix Hi (boundary between point in time 2i+2 and point in time 2i+3) 5600-1 are. shifted three columns to the right between the (2i + l)'th row and the (2i + 2)'th row. The above-described relationship between parity check polynomials and parity check matrix H is also similar for an LDPC-CC parity check matrix of a time varying period of 2 or a time varying period of m described in the above embodiments and another embodiments. Transmission sequence u is represented as u=(Xi)0, X2,o, Po, Xi.i, X2,i, Pi, •••> Xi,j, X2,i, Pi, ...)T, where Xi.i, X2,i are information and Pi is parity. Transmission sequence u is a systematic code. In this case, first sub-matrix Hi in FIG.58A satisfies the condition Xi>2i-3 + Xi,2i + X2,2i-2 + X2,2i + P2i-5 + P2i-3 + P2i = 0. Similarly, second sub-matrix H2 in FIG.58B satisfies the condition Xi, (2i + i) - 4 + XIF (2i + l) + Xi, (2i+l) -c 5 + X2, (2i + l) - 3 + X2, (2i+l) + P(2i + 1) - 3 + P(2i+1) -1 + P{2i+1) = 0. ■ As described above, although the relationship between parity check polynomials and parity check matrix H has been described taking the cases of coding rates of 1/2 and 2/3 as examples, the relationship between parity check polynomials and parity check matfix H holds true in a similar way irrespective of the coding rate. In particular, details regarding an LDPC-CC (convoiutional code) parity check matrix H are given in Non-Patent Document 17 and Non-Patent Document 18. (Another Embodiment 13) Here, differences between Embodiment 7, Embodiment 8, another Embodiment 5, another Embodiment 6, and another Embodiment 8, and Non-Patent Document 16, are described. Non-Patent Document 16 describes a method of designing an LDPC-CC of a time varying period of 4 from an LDPC-BC (Low-Density Parity-Check Block Code) in the case of a coding rate of 1/2. A brief description of the LDPC-CC design method of Non-Patent Document 16 is given below using accompanying drawings. FIG.60 is a drawing provided to explain the design method described in Non-Patent Document 16. Using FIG.16, a method of designing an LDPC-CC of a time varying period of 4 from an LDPC-BC of a coding rate of 1/2 will be described. In Non-Patent Document 16, an LDPC-CC parity check matrix is generated by means of Step 1) through Step 3) shown below. Step 1) An LDPC-BC serving as an LDPC-CC base is set. According to Non-Patent Document 16, an m-rowx2m-column LDPC-BC is necessary in order to create an LDPC-CC of a coding rate of 1/2 and a time varying period of m- Parity check matrix 5801 in FIG.60A is an example of a parity check matrix of an LDPC-BC serving as a base of an LDPC-CC of a time varying period of 4. As explained above, in the case of a time varying period of 4, a 4-rowx8-column LDPC-BC parity check matrix is used as a base parity check matrix. Step 2) Then predetermined processing is executed on parity check matrix 5801, and parity check matrix 5802 is created (see FIG.60B). Since the actual processing is described in Non-Patent Document 16, a description thereof is omitted here. Step 3) Then "ll"s are added to parity check matrix 5802 and parity check matrix 5803 is created, as shown in FIG.60C. In this way an LDPC-CC parity check matrix of a time varying period of 4 is created from a 4-rowx8-column LDPC-BC by means of Step 1) through Step 3) in Non-Patent Document 16. A parity check polynomial corresponding to parity check matrix 5803 obtained in this way is represented by Equation 152. [152] (jf + "•+ &v+l)#!))*#1 ■ +—+£?*+ l)p(D) = 0... (Equation 152) In Equation 152, it is assumed that al, a2, ..., ap are integers of 1 or above (where a 1 #a2#...#ap), and bl, b2, ..., bq are integers of 1 or above (where b l#b2#.. .#bq). As can be seen from FIG.60C, with an LDPC-CC of a time varying period of 4 there are four different parity check polynomials based on Equation 152. Therefore, when designing an LDPC-CC of a time varying period of 4, since a 4-row*8-column LDPC-BC parity check matrix is used as a base and "ll"s are added as shown in FIG.60C in Step 3), this means that ai<4 (where i = l, 2, ..., p) and bj<4 (where j = l, 2, ..., q) in all four different parity check polynomials configuring the base LDPC-BC parity check matrix. That is to say, when designing an LDPC-CC of a time varying period of. 4 in accordance with Non-Patent Document 16, the maximum constraint length is 4+1=5. Similarly, when designing an LDPC-CC of a time varying period of m by means of the design method of Non-Patent Document 16, aim+1 is to hold true between maximum value Amax of ai (where i=l, 2, ..., p), and the condition Braax>rn+1 is to hold true between maximum value Bmax of bi (where i = l, 2, ..., q). In order to obtain good received quality, it is desirable for either Am8X or Bmax to be made 100 or above. • A row weight of between 7 and 12 is to be set. On the other hand, if an LDPC-CC of a time varying period of 2 enabling a puncturing pattern to be found most easily is designed by means of the design method of Non-Patent Document 16, the maximum constraint length is 3, and the conditions ai<2 (where i=l, 2, ..., p) and bj<2 (where j = l, 2, ..., q) hold true in two different Equations 152. Therefore, if an LDPC-CC of a time varying period of 2 is designed using the design method of Non-Patent Document 16, the row weight is a maximum of 6. Therefore, of the requirements for an LDPC-CC of a time varying period of 2 for achieving both an improvement in received quality and support for a plurality of coding rates by means of puncturing described in Embodiment 7, the requirement "A row weight of between 7 and 12 is to be set" is a distinctive requirement of the invention of the present application. (Another Embodiment 14) Here, a loop 6 of a time-invariant LDPC-CC and an LDPC-CC of a time varying period of 2 will be described in detail. (1) First, a description will be given relating to a time-invariant LDPC-CC of a coding rate of n/n+1. A polynomial of data (information) XI is designated Xl(D), a polynomial of data (information) X2 is designated X2(D), a polynomial of data (information) X3 is designated X3(D), ..., a polynomial of data (information) Xn is designated Xn(D), and a polynomial of parity P is designated P(D), and the parity check polynomial below is considered. [153] #+...+D#)xi(D)+#l+---+If2'r2)x2{D) /r, . ict>y i , \ / \ / 7 U/ \ - (Equation 153) In Equation 153, it is assumed that ai,i, ai,2, -.., ai,ri are integers (where aifi/ajf2#--.#aijri). Also, it is assumed that a2,i, a2,2, ■••) a2,r2 are integers (where a2>i#a2,2#...#a2,r2). Furthermore, it is assumed that a;], aj,2, ■•-, aj,ri (where i = 3, ..., n-1) are integers (where ai,i#aii2#...#aijri). Moreover, it is assumed that a„,i, an,2, ..., an>rn are integers (where an,i#an>2#.. ./an,rn). Also, it is assumed that ei, e2, ••-, ew are integers (where e i#eii1- - .#ew). [Theorem 1] In a time-invariant LDPC-CC based on a parity check polynomial of Equation 153, when three or more terms are present in any of X1(D), X2(D), X3(D), ..., Xn(D), and P(D), at least one loop 6 is present. [Example] With regard to X1(D), consider a case in which terms (D +D +1)X1(D) are present in a parity check polynomial. In this case, a sub-matrix generated by extracting only a part relating to X1(D) is represented as shown in FIG.61, and a loop 6 is present as indicated by dotted line 5901. [Proof] If it can be proved for X1(D) that at least one loop 6 is present when three or more terms are present, it can be proved that the same also holds true for X2(D), X3(D), .... Xn(D), and P(D), by considering them as being replaced by X1(D). Therefore, X1(D) will be focused on. For Equation 153, in a parity check matrix H in which two terms are present in X1(D), a sub-matrix generated by extracting only a part relating to X1(D) is represented as shown in FIG.62, and a loop is not present. Next, consider Equation 154 in which three terms are present in X1(D) with respect to Equation 153. [154] {j[f#+If#+If#)xi(D)+ifir2-l+-+lf2'r2)jn{D) / \ / v / \ / \ (Equation 154) +• • •+ [pf**+• • -+jf#)x{p)+[lf+• • -+Ifw)F{D) = 0 At this time, generality is not lost even if ai,i>ai,2>ai,3- Thus, Equation 154 is represented as shown below, [155] i \ ;. / \ , , (Equation 155) +■ • •+(//*'+• • ■+rrrn)Xr(p)+(lJ!l+•■ ■+Ifw)F{D)=Q where a and 0 are natural numbers. At this time, consider Xl(D) related terms, that is, (Dal,3 + a + p + Dal'3 + p+ DaI'3)Xl(D), in Equation 155. In parity check matrix H, a sub-matrix generated by extracting only a part relating to X1(D) is represented as shown in FIG.63. Therefore, a loop 6 formed by elements 6101 necessarily occurs irrespective of the values of a and p. If four or more terms relating to Xl(D) are present, and three of the four or more terms are selected, a loop 6 is formed by the three selected elements (see FIG.63). Thus, a loop 6 is present if four or more terms relating to Xl(D) are present. Therefore, a loop 6 is present if three or more terms relating to Xl(D) are present in a parity check polynomial. A similar proof can also be carried out for X2(D), X3(D), ..., Xn(D), and P(D). Thus, Theorem l has been proved. (End of proof) (2) Next, a description will be given to an important matter relating to an LDPC-CC of a time varying period of 2. In an LDPC-CC of a time varying period of 2, a polynomial of data (information) XI is designated Xl(D), a polynomial of data (information) X2 is designated X2(D), a polynomial of data (information) X3 is designated X3(D), ..., a polynomial of data (information) Xn is designated Xn(D), and a polynomial of parity P is designated P(D). Then a parity check polynomial of Equation 156 is considered as "check equation #1." [156] K..+#+(#+-4#)BW (Equation 156) + ■ ••+ (fT1 + ■ '■+]fn'rn)xt(D)+(D61 + ■ • ■+£fw)p{D)=0 In Equation 156, it is assumed that a111, a i, 2 a i, r i are integers (where aiii#ai,2#...#ai,ri). Also, it is assumed that a2,i, a2,2, •■-, a2,r2 are integers (where a2,i#a2,2#..-#a2,T2)- Furthermore, it is assumed that a;,], aif2, ..., ai>ri (where i = 3, ..., n-1) are integers (where aj,t#ai##---#ai.ri)- Moreover, it is assumed that an,i, an>2, •-., a„,f„ are integers (where an,i#an,2#.. .#an,rn). Also, it is assumed that ei, e2, ..., ew are integers (where ei#e2#...#ew). Then a parity check polynomial of Equation 157 is considered as "check equation #2." [157] (D#+...+ZjM)xi(D) + (D#+...+/#)x2(D) rFnn.tinn 157. / \ / \ / \ i \ (Equation 157) +• • -+{jjhl+• • •+JD6#")#>Si (where i = 3, ..., n-1) are integers (where bi>i#bi>2#...Tibi)Sj). Moreover, it is assumed that b„,i, bn,2, ••-, bn,sn are integers (where bn,i#bn,2#...#bn>sn). Also, it is assumed that fi, f2, ..., fv are integers (where f x±f2±.. .#fv). Then an LDPC-CC of a time varying period of 2 provided by "check equation #1" and "check equation #2" is considered. [Theorem 2] With an LDPC-CC of a time varying period of 2 based on a parity check polynomial of Equation 156 and parity check polynomial of Equation 157, at least one loop 6 is present when the following condition is satisfied in a parity check polynomial of Equation 156: "y is present such that (ay>j, ay>j, ay,k) are all odd numbers or all even numbers (where i/j#k), or z is present such that (ei, ej, e*) are all odd numbers or all even numbers or (bZij, bZij, bz,k) are all odd numbers or all even numbers (where i#j/k), or (fj, fj, ft) are all odd numbers or all even numbers." [Example] With regard to X1(D) of "check equation #1", consider a case in which terms (D6 + D2+l )X 1 (D) are present in a parity check polynomial. In this case, a sub-matrix generated by extracting only a part relating to X1(D) in parity check matrix H is represented as shown in FIG.64, and a loop 6 is present as indicated by dotted line 6203. [Proof] If it can be proved for X1(D) that a loop 6 is present when (ai,i, aij, ai,k) are all odd numbers or all even numbers (where i#j/lc), it can be proved that the same also holds true for X2(D), X3(D), ..., Xn(D), and P(D), by considering them as being replaced by X1(D). Therefore, X1(D) will be focused on. Also, by proving in a similar way that this holds true in a parity check polynomial of Equation 156, that is, "check equation #1," it can be proved that this also holds true in a parity check polynomial of Equation 157, that is, "check equation #2." Therefore, a parity check polynomial of Equation 156, that is, "check equation #1," will be taken into account. When two even numbers or two odd numbers are present in ai,; (where i=l, 2, ..., rl) in terms relating to X1(D) of Equation 156, a sub-matrix generated by extracting only a part relating to X1(D) is as shown in FIG.65. In FIG.65, sub-matrix 6301 is a sub-matrix corresponding to X1(D) of "check equation #1," and sub-matrix 6302 is a sub-matrix corresponding to X1(D) of "check equation #2." As can be seen from sub-matrix 6301 in FIG.65, a loop does not occur with only the presence of two even numbers or two odd numbers in ai.j (where i=l, 2, ..., rl) of a parity check polynomial of Equation 156 ("check equation #1"). Next, if Equation 158 is considered when three terms are present for X1(D) with respect to Equation 156 and (aij, ai.j, ai,k) are all odd numbers or all even numbers, this can be represented as Equation 159. Generality is not lost even if a),i>aij2>aj,3. [158] Here, p and q are natural numbers, At this time, consider X1(D) related terms, that is, (D.i,3 + 2p + 2q + Dn,3 + 2q+ D*i.3)xi(D), in Equation 159. In parity check matrix H, a sub-matrix generated by extracting only a part relating to X1(D) is represented as shown in FIG.66. In the case of a time varying period of 2, sub-matrix 6401 in FIG.66 entirely comprises "check equation #1" of Equation 159, and therefore the state is similar to that in FIG.63 described in the proof of Theorem 1. Therefore, a loop 6 is formed by elements 6101 as shown in FIG.66 with "check equation #1" only, irrespective of the values of p and q. When four or more terms relating to X1(D) are present, if three of the four or more terms are selected and (ai,j, ai,j, ai,k) are all odd numbers or all even numbers in the three selected terms, a loop 6 is formed by elements 6101 as shown in FIG.66. From the above, a loop 6 is present if, for X1(D), (ai.j, aij, ai,k) are all odd numbers or all even numbers (where i#j#k). The same can also be said for X2(D), X3(D), ..., Xn(D), and P(D). The same can be said for "check equation #2" as for "check equation #1," and therefore Theorem 2 has been proved. (End of proof) [Theorem 3] With an LDPC-CC of a time varying period of 2 based on a parity check polynomial of Equation 156 and parity check polynomial of Equation 157, at least one loop 6 is present when five or more terms are present in any of Xl(D), X2(D), X3(D), ..., Xn(D), and P(D) of a parity check polynomial of Equation 156, or when five or more terms are present in any of X1(D), X2(D), X3(D), ..., Xn(D), and P(D) of a parity check polynomial of Equation 157. [Proof] When five or more terms are present in any of X1(D), X2(D), X3(D), ..., Xn(D), and P(D), Theorem 2 is necessarily satisfied. Therefore, Theorem 3 has been proved. (End of proof) The importance of another Embodiment 9 is clear from the above. (Another Embodiment 15) First, an LDPC-CC of a time varying period of 4 with good characteristics will be described. A case in which the coding rate is 1/2 is described below as an example. Consider Equations 160-1 through 160-4 as parity check polynomials of an LDPC-CC for which the time varying period is 4. At this time, X(D) is polynomial representation of data (information) and P(D) is a parity polynomial representation. Here, in Equations 160-1 through 160-4, parity check polynomials have been assumed in which there are four terms in X(D) and P(D) respectively, the reason being that four or more terms are desirable from the standpoint of obtaining good received quality. [160] i&1+lf+lf+iyAHD)+{rt]+Lt2+r?3+lfy(l>h<) ■•• (Equation 160-1) {lJ,1+]f+lf+iyt4)x(D)+ijf+]f+jf+]j'*)F{D)=0 ... (Equation 160-2) {tf+D*+lf+Da1#)+{lf+lf+lf+JDl,*U») = <> -• (Equation 160-3) (Lf+lf+lf+lf)>&h{lf+Lr+lf+LfAHz>h<> ••• (Equation 160-4) In Equation 160-1, it is assumed that al, a2, a3, and a4 are integers (where al #a2#a3#a4). Also, it is assumed that bl, b2, b3, and b4 are integers (where b 1 #b2#b3#b4). A parity check polynomial of Equation 160-1 is called "check equation #1," and a sub-matrix based on a parity check polynomial of Equation 160-1 is designated first sub-matrix HI. In Equation 160-2, it is assumed that Al, A2, A3, and A4 are integers (where Al#A2#A3#A4). Also, it is assumed that Bl, B2, B3, and B4 are integers (where B 1#B2#B3#B4). A parity check polynomial of Equation 160-2 is called "check equation #2," and a sub-matrix based on a parity check polynomial of Equation 160-2 is designated second sub-matrix H2, In Equation 160-3, it is assumed that al, a2, a3, and a4 are integers (where a l/a2/a3#a4). Also, it is assumed that pi, p2, P3, and P4 are integers (where p 1 #P2#p3#p4). A parity check polynomial of Equation 160-3 is called "check equation #3," and a sub-matrix based on a parity check polynomial of Equation 160-3 is designated third sub-matrix H3. In Equation 160-4, it is assumed that El, E2, E3, and E4 arc integers (where E1#E2#E3#E4). Also, it is assumed that Fl, F2, F3, and F4 are integers (where F 1#F2#F3#F4). A parity check polynomial of Equation 160-4 is called "check equation #4," and a sub-matrix based on a parity check polynomial of Equation 160-4 is designated fourth sub-matrix H4. Next, an LDPC-CC of a time varying period of 4 is considered that generates a parity check matrix such as shown in FIG.19 from first sub-matrix Hi, second sub-matrix H2, third sub-matrix H3, and fourth sub-matrix H4. At this time, if a remainder after dividing the values of combinations of orders X(D) and P(D) (al, a2, a3, a4), (bl, b2, b3, b4), (Al, A2, A3, A4), (Bl, B2, B3, B4), (al, a2, o3, a4), (pi, p2, p3, P4), (El, E2, E3, E4), (Fl, F2, F3, F4) in Equations 160-1 through 160-4 by 4 is designated k, provision is made for one each of remainders 0, 1, 2, and 3 to be included in four coefficient sets represented as shown above (for example, (al, a2, a3, a4)), and to hold true for all above four coefficient sets. For example, if orders (al, a2, a3, a4) of X(D) of "check equation #1" are set as (al, a2, a3, a4) = (8, 7, 6, 5), remainders k after dividing orders (al, a2, a3, a4) by 4 are (0, 3, 2, 1), and one each of 0, 1, 2, 3 are included in the four coefficient sets as remainders (k). Similarly, if orders (bl, b2, b3, b4) of "check equation #1" P(D) are set as (bl, b2, b3, b4)=(4, 3, 2, 1), remainders k after dividing orders (bl, b2, b3, b4) by 4 are (0, 3, 2, 1), and one each of 0, 1, 2, 3 are included in the four coefficient sets as remainder (k). It is assumed that the above "remainder" related condition (hereinafter also referred to as "remainder rule") also holds true for the four coefficient sets of X(D) and P(D) of the other parity check polynomials ("check equation #2," "check equation #3," and "check equation #4"). By this means, the column weight of parity check matrix H configured from Equations 160-1 through 160-4 becomes 4 for all columns, and a regular LDPC code can be formed. Here, a regular LDPC code is an LDPC code that is defined by a parity check matrix for which each column weight is fixed, and is characterized by the fact that its characteristics are stable and an error floor is unlikely to occur. In particular, since the characteristics are good when the column weight is 4, an LDPC-CC offering good reception performance can be obtained by generating an LDPC-CC as described above. Table 6 shows examples of LDPC-CCs (LDPC-CCs #1 through #3) of a time varying period of 4 and a coding rate of 1/2 for which the above "remainder" related condition (remainder rule) holds true. In Table 6, LDPC-CCs of a time varying period of 4 are defined by four parity check polynomials: "check polynomial #1," "check polynomial #2," "check polynomial #3," and "check polynomial #4." [Table 6] Code Parity Check Polynomials LDPC-CC #1 of time varying period of 4 and coding rate 1/2 "Check polynomial #1" : (D4is+D43i+D*"+})X(D)+{D59S+£>313+D61+1)P(D)=0 "Check polynomial #2" : (Z)z"+Z)I,3+Z)I3O+l)X(Z))+(Z)S4S+Z)itt+D10S+l)P(Z))=0 "Check polynomial #3" : (£>5"+£»49i+jD326+l)X(£>)+(Z)56,+£>5O2+Z}3JI+l)p(Z))=0 "Checkpolynomial #4" : (D426+D329+D"+\)X(D)+(D321+D"+D42+1)P(D)=0 LDPC-CC #2 of time varying period of 4 and coding rate 1/2 "Check polynomial #1" "Check polynomial #2" "Check polynomial #3" "Check polynomial #4" (D$03+D4S4+D49+1 )X(D)HDi€9+D461+D401+1 )P(£>)=0 (D5l8+D473+i)2O3+l)X(£))-KD39S+D499+Z),45+l)P(D)=0 (D*°3+D39f7+D62+1 )X(D)+(£>2W+D267+Z>69+1 )P(D)=0 (Z>483+Z>38S+D94+1 )X(D)-K£>426+Z)415+£>',13+1 )P(D)=0 LDPC-CC #3 of time varying period of 4 and coding rate 1/2 "Check polynomial #1" "Check polynomial #2" "Check polynomial #3" "Check polynomial #4" (D*54+D447+Du+\)X(D)+(D49*+D231+D7+iyP(D)=0 (Dm+Di45+DM6+1 )X(D)+(D325+D7t+D66+1 )P(£>)=0 (D4X+DA2S+DW7+1 )X(D)+(D582+Z>4T+D4J+1 )P(£>)=0 (D434+D353+DU1+1 )X(D)+(D34S+D107+D3*+1 )P(£>)=0 In the above description, a case in which the coding rate is 1/2 has been described as an example, but a regular LDPC code is also formed and good received quality can be obtained when the coding rate is (n-l)/n if the above "remainder" related condition (remainder rule) holds true for four coefficient sets in information X1(D), X2(D), ..., Xn-l(D). In the case of a time varying period of 2, also, it has been confirmed that a code with good characteristics can be found if the above "remainder" related condition (remainder rule) is applied. An LDPC-CC of a time varying period of 2 with good characteristics is described below. A case in which the coding rate is 1/2 is described below as an example. Consider Equations 160-1 and 160-2 as parity check polynomials of an LDPC-CC for which the time varying period is 2. At this time, X(D) is polynomial representation of data (information) and P(D) is polynomial representation of parity. Here, in Equations 161-1 and 161-2, parity check polynomials have been assumed in which there are four terms in X(D) and P(D) respectively, the reason being that four or more terms are desirable from the standpoint of obtaining good received quality. [161] irf+lf+lf+]f)W+{jf+lf+lf+]f)rto=0"- (Equation 161-1) {lf+]f+lf+lf]#+{]0r+lf+J0r+lf)fi#'0... (Equation 161-2) In Equation 161-1, it is assumed that al, a2, a3, and a4 are integers (where al #a2#a3#a4). Also, it is assumed that bl, b2, b3, and b4 are integers (where b I#b2#b3#b4). A parity check polynomial of Equation 161-1 is called "check equation #1," and a sub-matrix based on a parity check polynomial of Equation 161-1 is designated first sub-matrix Hi. In Equation 161-2, it is assumed that Al, A2, A3, and A4 are integers (where A1#A2#A3# A4). Also, it is assumed that Bl, B2, B3, and B4 are integers (where B 1#B2#B3#B4). A parity check polynomial of Equation 161-2 is called "check equation #2," and a sub-matrix based on a parity check polynomial of Equation 160-2 is designated second sub-matrix H2. Next, an LDPC-CC of a time varying period of 2 generated from first sub-matrix Hi and second sub-matrix H2 is considered. At this time, if a remainder after dividing the values of combinations of orders of X(D) and P(D) (al, a2, a3, a4), (bl, b2, b3, b4), (Al, A2, A3, A4), (B1, B2, B3, B4), in Equations 161-1 and 161-2 by 4 is designated k, provision is made for one each of remainders 0, 1, 2, and 3 to be included in four coefficient sets represented as shown above (for example, (al, a2, a3, a4)), and to hold true for all above four coefficient sets. For example, if orders (al, a2, a3, a4) of X(D) of "check equation #1" are set as (al, a2, a3, a4) = (8, 7, 6, 5), remainders k after dividing orders (al, a2, a3, a4) by 4 are (0, 3, 2, 1), and one - each of 0, 1, 2, 3 are included in the four coefficient sets as remainder (k). Similarly, if orders (bl, b2, b3, b4) of P(D) of "check equation #1" are set as (bl, b2, b3, b4)=(4, 3, 2, 1), remainders k after dividing orders (bl, b2, b3, b4) by 4 are (0, 3, 2, 1), and one each of 0, 1, 2, 3 are included in the four coefficient sets as remainder (k). It is assumed that the above "remainder" related condition (remainder rule) also holds true for the four coefficient sets of X(D) and P(D) of "check equation #2." By this means, the column weight of parity check matrix H configured from Equations 161-1 and 161-2 becomes 4 for all columns, and a regular LDPC code can be formed. Here, a regular LDPC code is an LDPC code that is defined by a parity check matrix for which each column weight is fixed, and is characterized by the fact that its characteristics are stable and an error floor is unlikely to occur. In particular, since the characteristics are good when the column weight is 8, an LDPC-CC enabling reception performance to be further improved can be obtained by generating an LDPC-CC as described above. Table 7 shows examples of LDPC-CCs (LDPC-CCs #1 and #2) of a time varying period of 2 and a coding rate of 1/2 for which the above "remainder" related condition (remainder rule) holds true. In Table 7, LDPC-CCs of a time varying period of 2 are defined by two parity check polynomials: "check polynomial #1" and "check polynomial #2." [Table 7] Code Parity Check Polynomials LDPC-CC #1 of time varying period of 2 and coding rate 1/2 "Check polynomial #1" : (Z)55l+Z>',65+£>9*+l)X(Z))+(Z)407+Z)3S6+Z)373+l)P(Z))=0 "Check polynomial #2" : (£>443+O433+£»54+l)X(i>)+(£>5594-i?i57+Z)54S+l)P(Z))=0 LDPC-CC #2 of time varying period of 2 and coding rate 1/2 "Check polynomial #1" : (Di6S+D,90+D99+l)X(D)+{Dl9S+DiA6+D69+\)PiD)=0 "Check polynomial #2" : (ZJ275+Z)226+JD213+1)X(Z))+(Z)298+JD,',7+£>4S+1)P(£>)=0 In the above description (LDPC-CCs of a time varying period of 2), a case in which the coding rate is 1/2 has been described as an example, but a regular LDPC code is also formed and good received quality can be obtained when the coding rate is (n-l)/n if the above "remainder" related condition (remainder rule) holds true for four coefficient sets in information X1(D), X2(D), ..., Xn-l(D). In the case of a time varying period of 3, also, it has been confirmed that a code with good characteristics can be found if the "remainder" related condition below is applied. LDPC-CC of a time varying period of 3 with good characteristics is described below. A case in which the coding rate is 1/2 is described below as an example. Consider Equations 162-1 through 162-3 as parity check polynomials of an LDPC-CC for which the time varying period is 3. At this time, X(D) is polynomial representation of data (information) and P(D) is a parity polynomial representation. Here, in Equations 162-1 through 162-3, parity check polynomials are assumed such that there are three terms in X(D) and P(D) respectively. [162] [if+if+lf)&)4lf+if+]&&)=* ■■■ (Equation 162-1) {lf+lf+lfHD)+{lf+lf+lfHD)=0 •• (Equation 162-2) =0 ... (Equation 162-3) In Equation 162-1, it is assumed that al, a2, and a3 are integers (where al#a2#a3). Also, it is assumed that bl, b2 and b3 are integers (where bl#b2#b3). A parity check polynomial of Equation 162-1 is called "check equation #1," and a sub-matrix based on a parity check polynomial of Equation 162-1 is designated first sub-matrix Hj. In Equation 162-2, it is assumed that Al, A2 and A3 are integers (where A1#A2#A3). Also, it is assumed that Bl, B2 and B3 are integers (where B1#B2#B3). A parity check polynomial of Equation 162-2 is called "check equation #2," and a sub-matrix based on a parity check polynomial of Equation 162-2 is designated second sub-matrix H2. In Equation 162-3, it is assumed that al, a2 and a3 are integers (where al#a2#a3). Also, it is assumed that pi, P2 and p3 are integers (where pl#p2#p3). A parity check polynomial of Equation 162-3 is called "check equation #3," and a sub-matrix based on a parity check polynomial of Equation 162-3 is designated third sub-matrix H3. Next, an LDPC-CC of a time varying period of 3 generated from first sub-matrix Hi, second sub-matrix H2 and third sub-matrix H3 is considered. At this time, if a remainder after dividing the values of combinations of orders of X(D) and P(D) (al, a2, a3), (bl, b2, b3), (Al, A2, A3), (Bl, B2, B3), (al, cc2, a3), (pi, p2, p3) in Equations 162-1 through 162-3 by 3 is designated k, provision is made for one each of remainders 0, 1, and 2 to be included in three coefficient sets represented as shown above (for example, (al, a2, a3)), and to hold true for all above three coefficient sets. For example, if orders (al, a2, a3) of X(D) of "check equation #1" are set as (al, a2, a3)=(6, 5, 4), remainders k after dividing orders (al, a2, a3) by 3 are (0, 2, 1), and one each of 0, 1, 2 are included in the three coefficient sets as remainder (k). Similarly, if orders (bl, b2, b3) of P(D) of "check equation #1" are set as (bl, b2, b3) = (3, 2, 1), remainders k after dividing orders (bl, b2, b3) by 3 are (0, 2, 1), and one each of 0, 1, 2 are included in the three coefficient sets as remainder (k). It is assumed that the above "remainder" related condition (remainder rule) also holds true for the three coefficient sets of X(D) and P(D) of "check equation #2"and "check equation #3." Generating an LDPC-CC in this way enables a regular LDPC-CC code to be generated. Furthermore, when BP decoding is performed, belief in "check equation #2" and belief in "check equation #3" are propagated accurately to "check equation #1," belief in "check equation #1" and belief in "check equation #3" are propagated accurately to "check equation #2," and belief in "check equation #1" and belief in "check equation #2" are propagated accurately to "check equation #3." Consequently, an LDPC-CC with better received quality can be obtained. This is because, - when considered in column units, positions at which a "1" is present are arranged so as to propagate belief accurately, as described above. The above belief propagation will be described below using accompanying drawings. FIG.67A shows parity check polynomials and a parity check matrix H configuration of LDPC-CC of a time varying period of 3. "Check equation #1" illustrates a case in which (al, a2, a3)=(2, 1, 0) and (bl, b2, b3)=(2, 1, 0) in a parity check polynomial of Equation 162-1, and remainders after dividing the coefficients by 3 are as follows: (al%3, a2%3, a3%3) = (2, 1, 0), (bl%3, b2%3, b3%3) = (2, 1, 0), where "Z%3" represents a remainder after dividing Z by 3. "Check equation #2" illustrates a case in which (Al, A2, A3) = (5, 1, 0) and (Bl, B2, B3)=(5, 1, 0) in a parity check polynomial of Equation 162-2, and remainders after dividing the coefficients by 3 are as follows: (Al%3, A2%3, A3%3) = (2, 1, 0), (Bl%3, B2%3, B3%3) = (2, 1, 0). "Check equation #3" illustrates a case in which (al, a2, a3)=(4, 2, 0) and (pi, 02, p3)=(4, 2, 0) in a parity check polynomial of Equation 162-3, and remainders after dividing the coefficients by 3 are as follows: (al %3, a2%3, a3%3) = (l, 2, 0), (Pl%3, P2%3, P3%3) = (1, 2, 0). Therefore, the example of LDPC-CC of a time varying period of 3 shown in FIG.67A satisfies the above-described "remainder" related condition (remainder rule), that is, a condition whereby (al%3, a2%3, a3%3), (bl%3, b2%3, b3%3), (Al%3, A2%3, A3%3), (Bl%3, B2%3, B3%3), (al%3, a2%3, a3%3), (Pl%3, P2%3, P3%3) are any of the following: (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), (2, 1, 0). Returning to FIG.67A again, belief propagation will now be explained. Through column computation of column 6506 in BP decoding, for a "1" of area 6501 of "check equation #1," belief is propagated from a "1" of area 6504 of "check equation #2" and a "1" of area 6505 of "check equation #3." As described above, a "1" of area 6501 of "check equation #1" is a coefficient for which a remainder after division by 3 is 0 (a3%3 = 0 (a3 = 0) or b3%3=0 (b3 = 0)). Also, a "1" of area 6504 of "check equation #2" is a coefficient for which a remainder after division by 3 is 1 (A2%3 = 1 (A2=l) or B2%3=1 (B2=l)). Furthermore, a "1" of area 6505 of "check equation #3" is a coefficient for which a remainder after division by 3 is 2 (a2%3=2 (a2=2) or 02%3=2 (p2 = 2)). Thus, for a "1" of area 6501 for which a remainder is 0 in a coefficient of "check equation #1," in column computation of column 6506 in BP decoding, belief is propagated from a "1" of area 6504 for which a remainder is 1 in a coefficient of "check equation #2" and a "1" of area 6505 for which a remainder is 2 in a coefficient of "check equation #3." Similarly, for a "1" of area 6502 for which a remainder is 1 in a coefficient of "check equation #1," in column computation of column 6509 in BP decoding, belief is propagated from a "1" of area 6507 for which a remainder is 2 in a coefficient of "check equation #2" and a "1" of area 6508 for which a remainder is 0 in a coefficient of "check equation #3." Similarly, for a "1" of area 6503 for which a remainder is 2 in a coefficient of "check equation #1," in column computation of column 6512 in BP decoding, belief is propagated from a "1" of area 6510 for which a remainder is 0 in a coefficient "check equation #2" and a "1" of area 6511 for which a remainder is 1 in a coefficient "check equation #3." A supplementary explanation of belief propagation will now be given using FIG.67B. FIG.67B shows the belief propagation relationship of terms relating to X(D) of "check equation #1" through "check equation #3" in FIG.67A. "Check equation #1" through "check equation #3" in FIG.67A illustrate cases in which (al, a2, a3) = (2, 1, 0), (Als A2, A3) = (5, 1, 0), and (ol, a2, o3) = (4, 2, 0), in terms relating to X(D) of Equations 162-1 through 162-3. In FIG.67B, terms (a3, A3, a3) inside squares indicate coefficients for which a remainder after division by 3 is 0, terms (a2, A2, 1} ai,2, ai,3), (a2,i, a2>2, a2,3)> ••-, (a„-i,i, an-i,2» an_ii3), (bl, b2, b3), (Aj,i, Ai,2, Ai,3>, (AJ,I, A2,2, A2,3), ••-, (A„.1,1, A„.i>2, An-1,3). (Bl, B2, B3), (01,1, 01,2, at,3), (a2>i, a2,2, a2,3), ..., (an-i.i, a„.i>2, an_i>3), (pi, p2, P3) in Equations 163-1 through 163-3 by 3 is designated k, provision is made for one each of remainders 0, 1, and 2 to be included in three coefficient sets represented as shown above (for example, (a 1,1, ai?2, ai>3)), and to hold true for all above three coefficient sets. That is to say, provision is made for (ai,i%3, ai,2%3, ai,3%3), (a2,i%3, a2,2°/o3, a2>3%3) (a„.i,i%3, a„.i,2%3, a „.,,3%3), (bl%3, b2%3, b3%3), (A>,i%3, A,i2%3, Ai,3%3), (A2,i%3, A2,2%3, A2)3%3), ..., (AB.I,I%3, An.i,2%3, A„.i,3%3), (Bl%3, B2%3, B3%3), (a1>t%3, ai>2%3, a,,3%3), (a2>1%3, a2,2%3, a2>3%3), ..., (o,lU%3, an.i,2%3, a.,.1,3%3), (Pl%3, p2%3, p3%3) to be any of the following: (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), (2, 1, 0). Generating an LDPC-CC in this way enables a regular LDPC-CC code to be generated. Furthermore, when BP decoding is performed, belief in "check equation #2" and belief in "check equation #3" are propagated accurately to "check equation #1," belief in "check equation #1" and belief in "check equation #3" are propagated accurately to "check equation #2," and belief in "check equation #1" and belief in "check equation #2" are propagated accurately to "check equation #3." Consequently, an LDPC-CC with better received quality can be obtained in the same way as in the case of a coding rate of 1/2. Table 8 shows examples of LDPC-CCs (LDPC-CCs #1, #2, #3, #4, and #5) of a time varying period of 3 and a coding rate of 1/2 for which the above "remainder" related condition (remainder rule) holds true. In Table 8, LDPC-CCs of a time varying period of 3 are defined by three parity check polynomials: "check (polynomial) equation #1," "check (polynomial) equation #2," and "check (polynomial) equation #3." [Table 8] Code Parity Check Polynomials LDPC-CC #1 of time varying period of 3 and coding rate 1/2 "Check polynomial #1" : (£)428+JD32i+l)X(D)+(Z)J38+Z>33z+I)P(D)=0 "Check polynomial #2" : (Dn,+Z)3'0+ OXtDJ+CD#+D'+l#ZJ#O "Check polynomial #3" : (j/°+D™+ l)X(D)+0i6*+Dl42+l)P(D)#O LDPC-CC #2 of time varying period of 3 and coding rate 1/2 "Check polynomial #1" : (Z)S62+Z)7l+l)X(Z))-KZ>325+D15i+l)P(Z))=0 "Check polynomial #2" : (£>215+£>106+1)X(D)+I42+1)P(I>)=0 "Check polynomial #3" : (Z)SM+Z)iSS'+l)X(Z?)-KZ)127+JD110+i)P(£>)=0 LDPC-CC #3 of time varying period of 3 and coding rate 1/2 "Check polynomial #1" : (D1I2+Z)53+1)X(Z))+(£>1I0+Z)88+1)P(£>)=0 "Check polynomial #2" : (£»103+Z>47+l)X(O)+14S+Z>89+l)X(D)+<£>146+£>49+l)P(i>)=0 LDPC-CC #4 of time varying period of 3 and coding rate 1/2 "Check polynomial #1" : (Z3350+£>322+l)X(£i)-KiD448+Z)338+l)P(Z))=0 "Check polynomial #2" : (i?S29+Z)32+I)X(£))+(Z)238+JD188+l)P(Z>)=0 "Check polynomial #3" : (D592+Z)572+l)X(D)+(Z)378+Z)i6!+l)P(Z))=0 LDPC-CC #5 of time varying period of 3 and coding rate 1/2 "Check polynomial #1" : (D410+Z382+l)xp)+(ZJ83J+£>47+l)P(Z))=0 "Check polynomial #2" : (Z)875+Z)796+l)X(Z))+(Z)962+£>87'+l)P(D)=o "Check polynomial #3" : (Z)60i+ZJ547+l)Xp)+(Z)950+JD439+l)P(D)-0 It has been confirmed that, as in the case of a time varying period of 3, a code with good characteristics can be found if the "remainder" related condition (remainder rule) below is applied to an LDPC-CC for which the time varying period is a multiple of 3 (for example, 6, 9, 12, ...). An LDPC-CC of a multiple of a time varying period of 3 with good characteristics is described below. The case of an LDPC-CC of a coding rate of 1/2 and a time varying period of-6 is described below as an example. Consider Equations 164-1 through 164-6 as parity check polynomials of an LDPC-CC for which the time varying period is 6. [164] At this time, X(D) is polynomial representation of data (information)and P(D) is a parity polynomial representation. With an LDPC-CC of a time varying period of 6, if i%6 = k (where k = 0, 1, 2, 3, 4, 5) is assumed for parity Pi and information Xi of time i, a parity check polynomial of Equation 164-(k+l) holds true. For example, if i=l, i%6=l (k=l), and therefore Equation 165 holds true. [165] (DW+i/W+/rlAri+(cT+/r+if3)P, = 0... (Equation 165) Here, in Equations 164-1 through 164-6, parity check polynomials are assumed such that there are three terms in X(D) and P(D) respectively. In Equation 164-1, it is assumed that al,l, al,2, al,3 are integers (where a 1,1 #al ,2#a 1,3). Also, it is assumed that bl,l, bl,2, and bl,3 are integers (where bl, l#bl ,2#b 1,3). A parity check polynomial of Equation 164-1 is caffed "check equation #1," and a sub-matrix based on a parity check polynomial of Equation 164-1 is designated first sub-matrix Hi. In Equation 164-2, it is assumed that a2,l, a2,2, and a2,3 are integers (where a2,I#a2,2#a2,3). Also, it is assumed that b2,l, b2,2, b2,3 are integers (where b2,1 #b2,2#b2,3). A parity check polynomial of Equation 164-2 is called "check equation #2," and a sub-matrix based on a parity check polynomial of Equation 164-2 is designated second sub-matrix H2. In Equation 164-3, it is assumed that a3,l, a3,2, and a3,3 are integers (where a3,I#a3,2#a3,3). Also, it is assumed that b3,l, b3,2, and b3,3 are integers (where b3, I#b3,2#b3,3). A parity check polynomial of Equation 164-3 is called "check equation #3," and a sub-matrix based on a parity check polynomial of Equation 164-3 is designated third sub-matrix H3. In Equation 164-4, it is assumed that a4,l, a4,2, and a4,3 are integers (where a4,I#a4,2#a4,3). Also, it is assumed that b4,l, b4,2, and b4,3 are integers (where b4, I#b4,2/b4,3). A parity check polynomial of Equation 164-4 is called "check equation #4," and a sub-matrix based on a parity check polynomial of Equation 164-4 is designated fourth sub-matrix H4. In Equation 164-5, it is assumed that a5,l, a5,2, and a5,3 are integers (where a5,I#a5,2#a5,3). Also, it is assumed that b5,l, b5,2, and b5,3 are integers (where b5, I#b5,2#b5,3). A parity check polynomial of Equation 164-5 is called "check equation #5," and a sub-matrix based on a parity check polynomial of Equation 164-5 is designated fifth sub-matrix H5. In Equation 164-6, it is assumed that a6,l, a6,2, and a6,3 are integers (where a6, I#a6,2#a6,3). Also, it is assumed that b6,l, b6,2, and b6,3 are integers (where b6,1 #b6,2#b6,3). A parity check polynomial of Equation 164-6 is called "check equation #6," and a sub-matrix based on a parity check polynomial of Equation 164-6 is designated sixth sub-matrix He. Next, an LDPC-CC of a time varying period of 6 is considered that is generated from first sub-matrix Hi, second sub-matrix H2, third sub-matrix H3, fourth sub-matrix H4, fifth sub-matrix H5, and sixth sub-matrix He. At this time, if a remainder after dividing the values of combinations of orders of X(D) and P(D) (al,l,al,2,al,3),(bl,l,bl)2,bl,3),(a2,l,a2,2,a2,3),(b2,l,b2,2,b2,3 ),(a3,l,a3,2,a3,3),(b3,l,b3,2,b3,3),(a4,l,a4,2,a4,3),(b4,l,b4,2,b4, 3),(a5,l,a5,2,a5,3),(b5,l,b5,2,b5,3),(a6,l,a6,2,a6,3),(b6,l,b6,2,b 6,3) in Equations 164-1 through 164-6 by 3 is designated k, provision is made for one each of remainders 0, 1, and 2 to be included in three coefficient sets represented as shown above (for example, (al, 1 ,al ,2,a 1,3)), and to hold true for all above three coefficient sets. That is to say, provision is made for (al,l%3,al,2%3,al,3%3),(bl,l%3,bl,2%3,bl,3°/o3),(a2,l%3,a2,2% 3,a2,3%3),(b2,l%3,b2,2%3,b2,3%3),(a3,l%3,a3,2%3,a3,3%3),(b3, I%3,b3,2%3,b3,3%3),(a4,l%3,a4,2%3,a4,3%3),(b4,l%3,b4,20/o3,b 4,3%3),(a5,l%3,a5,2%3,a5,3%3),(b5,l%3,b5,2%3,b5,3%3),(a6,l% 3,a6,2%3,a6,3%3),(b6,l%3,b6,2%3,b6,3%3) to be any of the following: (0,1,2),(0,2,1),(1,0,2),(1,2,0),(2,0,1),(2,1,0). By generating an LDPC-CC in this way, if an edge is present when a Tanner graph is drawn for "check equation #1," belief in "check equation #2 or check equation #5" and belief in "check equation #3 or check equation #6" are propagated accurately. Also, if an edge is present when a Tanner graph is drawn for "check equation #2," belief in "check equation #1 or check equation #4" and belief in "check equation #3 or check equation #6" are propagated accurately; if an edge is present when a Tanner graph is drawn for "check equation #3", belief in "check equation #1 or check equation #4" and belief in "check equation #2 or check equation #5" are propagated accurately; if an edge is present when a Tanner graph is drawn for "check equation #4," belief in "check equation #2 or check equation #5" and belief in "check equation #3 or check equation #6" are propagated accurately; if an edge is present when a Tanner graph is drawn for "check equation #5," belief in "check equation #1 or check equation #4" and belief in "check equation #3 or check equation #6" are propagated accurately; and if an edge is present when a Tanner graph is drawn for "check equation #6," belief in "check equation #1 or check equation #4" and belie fin "check equation #2 or check equation #5" are propagated accurately. Consequently, an LDPC-CC of a time varying period of 6 can maintain better error correction capability in the same way as when the time varying period is 3. In this regard, belief propagation will be described using FIG.67C. FIG.67C shows the belief propagation relationship of terms relating to X(D) of "check equation #1" through "check equation #6." In FIG.67C, a square indicates a coefficient for which a remainder after division by 3 in ax,y (where x=l, 2, 3, 4, 5, 6, and y=l, 2, 3) is 0; a circle indicates a coefficient for which a remainder after division by 3 in ax,y (where x=l, 2, 3, 4, 5, 6, and y=l, 2, 3) is 1; and a diamond-shaped box indicates a coefficient for which a remainder after division by 3 in ax,y (where x=l, 2, 3, 4, 5, 6, and y=l, 2, 3) is 2. As can be seen from FIG.67C, if an edge is present when a Tanner graph is drawn, for al,l of "check equation #1," belief is propagated from "check equation #2 or #5" and "check equation #3 or #6" for which remainders after division by 3 differ. Similarly, if an edge is present when a Tanner graph is drawn, for al,2 of "check equation #1," belief is propagated from "check equation #2 or #5" and "check equation #3 or #6" for which remainders after division by 3 differ. Similarly, if an edge is present when a Tanner graph is drawn, for al,3 of "check equation #1," belief is propagated from "check equation #2 or #5" and "check equation #3 or #6" for which remainders after division by 3 differ. While FIG.67C shows the belief propagation relationship of terms relating to X(D) of "check equation #1" through "check equation #6," the same can be said for terms relating to P(D). Thus, belief is propagated to each node in a "check equation #1" Tanner graph from coefficient nodes of other than "check equation #1." Therefore, reliabilities with low correlation are all propagated to "check equation #1," enabling an improvement in error correction capability to be expected. In FIG.67C, "check equation #1" has been focused upon, but a Tanner graph can be drawn in a similar way for "check equation #2" through "check equation #6," and belief is propagated to each node in a "check equation #K" Tanner graph from coefficient nodes of other than "check equation #K." Therefore, reliabilities with low correlation are all propagated to "check equation #K" (where K = 2, 3, 4, 5, 6), enabling an improvement in error correction capability to be expected. By providing for the orders of parity check polynomials of Equations 164-1 through 164-6 to satisfy the above-described "remainder" related condition (remainder rule) in this way, belief can be propagated efficiently in all check equations, and the possibility of being able to further improve error correction capability is increased. A case in which the coding rate is 1/2 has been described above for an LDPC-CC of a time varying period of 6, but the coding rate is not limited to 1/2. The possibility of obtaining good received quality can be increased when the coding rate is (n-l)/n (where n is an integer of 2 or above) if the above "remainder" related condition (remainder rule) holds true for three coefficient sets in information X1(D), X2(D) Xn-l(D). A case in which the coding rate is (n-l)/n (where n is an integer of 2 or above) is described below. Consider Equations 166-1 through 166-6 as parity check polynomials of an LDPC-CC for which the time varying period is 6. [166] At this time, X1(D), X2(D), ..., Xn-l(D) are polynomial representations of data (information) XI, X2, ..., Xn-1, and P(D) is polynomial representation of parity. Here, in Equations 166-1 through 166-6, parity check polynomials are assumed such that there are three terms in X1(D), X2(D), ..., Xn-l(D), and P(D) respectively. Thinking in the same way as in the case of the above coding rate of 1/2, and in the case of a time varying period of 3, the possibility of being able to obtain higher error correction capability is increased if the condition below () is satisfied in an LDPC-CC of a time varying period of 6 and a coding rate of (n-l)/n (where n is an integer of 2 or above) represented by parity check polynomials of Equations 166-1 through 166-6. In an LDPC-CC of a time varying period of 6 and a coding rate of (n-l)/n (where n is an integer of 2 or above), parity and information of time i are represented by Pi and X;,], Xj>2, ..., Xj In Equations 166-1 through 166-6, combinations of orders of X1(D), X2(D), ..., Xn-l(D), and P(D) satisfy the following condition. (a#i,i,i%3, a#i,i,2%3, a*\,i,3%3), (a#1>2,i%3, a*i,2>2%3, am.2.3%3), ..., (a#ilk,i%3, a#,,k,2%3, a#i,k,3%3), .-.., (a#i,„-i,i°/o3, a#i,„-i,2%3, a#i.„.i,3%3), (b#i.i%3, b#i,2%3, b#i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where k= 1, 2, 3, ..., n-1), and (a#2,i,i%3, a#2,i(2°/o3, a#2.i,3%3), (a#2,2,i%3, a#2,2,2%3, a#2>2,3%3), ..., (a#2,k,i%3, a#2.k,2%3, a#2,k,3%3), ..., (a#2,n-i,i%3, a#2,n-i,2°/o3, a#2.n-i,3%3), (b#2.i%3, b#2>2%3, b#2j30/o3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where k=l, 2, 3, ..., n-1), and (a#3,i,i%3, a#3,i,2%3, a#3,i,3%3), (a#3>2,i%3, a#3,2,2%3, a#3,2,3%3), ..., (a#3,k,i%3, a#3,k,2%3, a#3,k,3%3), ..., (a#3,n-i,i%3, a#3,n-i,2%3, a#3>n-i,3%3)> (b#3,i%3, b#3>2%3, b#3,3%3) are any of (0, 1, 2), (0, 2, 1), (l, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where k=l, 2, 3, ..., n-1), and (a#4,i,i%3, a#4,i,2%3, a#4,i,3%3), (a#4,2,i%3, a#4,2,2%3, a#4,2,3°/o3), ..., (a#4,k,i%3, a#4,k,2%3, a#4,k,3%3), ..., (a#4,n-i,i%3, a#4,n-i,2%3, a#4,n.i>3%3), (b#4,i%3, b#4,2%3, b#4,3%3) are any of (0, 1, 2), (0, 2, 1), (l, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where k=l, 2, 3, ..., n-1), and (a#5ii.i%3, a#s,i.2%3, a#s.i.3%3), (a#s.2,i%3, a#5,2,2%3, a#5,2,3%3), ..., (a#5,k,i%3, a#5,k,2%3, a#5,k,3%3), ..., (a#5,n-i,i%3, a#5,n-i,2%3, a#5,n.i,3%3), (b#5,i%3, b#5,2%3, b#5,3%3) are any of (0, 1, 2), (0, 2, 1), (l, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where k=l, 2, 3, ..., n-1), and (a*6,i,i%3, a#6,i,2%3, a#6,i,3%3), (a#6,2,i%3, a#6,2,2%3, a#6,2,3%3), ..., (a#6>k,i%3, a#6>k,2%3, a#6,k,3%3), ..., (a#6,n-i,i%3, a#6,n-i,2%3, a#6,n.i,3%3), (b#6,i%3, b#6j2%3, b#6,3%3) are any of (0, 1, 2), (0, 2, 1), (l, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where k=l, 2, 3, ..., n-1). In the above description, a code having high error correction capability has been described for an LDPC-CC of a time varying period of 6, but a code having high error correction capability can Uso be generated when an LDPC-CC of a time varying period of 3g (where g=l, 2, 3, 4, ...) (that is, an LDPC-CC for which the time varying period is a multiple of 3) is created in the same way as with the design method for an LDPC-CC of a time varying period of -3 or -6. A configuration method for this code is described in detail below. Consider Equations 168-1 through 168-3g as parity check polynomials of a.n LDPC-CC for which the time varying period is 3g (where g=l, 2f 3, 4, ...) and the coding rate is (n-l)/n (where n is an integer of 2 or above). ... (Equation 168-3g) At this time, X1(D), X2(D), ..., Xn-l(D) are polynomial representations of data (information) XI, X2, ..., Xn-1, and P(D) is polynomial representation of parity. Here, in Equations 168-1 through 168-3g, parity check polynomials are assumed such that there are three terms in X1(D), X2(D), ..., Xn-l(D), and P(D) respectively. In the case of an LDPC-CC of a time varying period of 3 and an LDPC-CC of a time varying period of 6, the possibility of being able to obtain higher error correction capability is increased if the condition below () is satisfied in an LDPC-CC of a time varying period of 3g and a coding rate of (n-l)/n (where n is an integer of 2 or above) represented by parity check polynomials of Equations 168-1 through 168-3g. In an LDPC-CC of a time varying period of 3g and a coding rate of (n-l)/n (where n is an integer of 2 or above), parity and information of time i are represented by Pi and Xj i, Xjt2> •••> Xj,n-i respectively. If i%3g = k (where k = 0, 1, 2, ..., 3g-l) is assumed at this time, a parity check polynomial of Equation 168-(k+l) holds true. For example, if i = 2, i%3g = 2 (k = 2), and therefore Equation 169 holds true. [169] ... (Equation 169) In Equations 168-1 through 168-3g, it is assumed that a#k,P,i, a#k,p,2, and a#k,P,3 are integers (where a#k,P,i#a#k,p,2#a#k,P,3) (where k=l, 2, 3, ..., 3g, and p = l, 2, 3, ..., n-1). Also, it is assumed that b#k,i, b#k,2, and b#k,3 are integers (where b#k,i#b#k,2#b#k,3)- A parity check polynomial of Equation 168-k (where k=l, 2, 3, ..., 3g) is called "check equation #k," and a sub-matrix based on a parity check polynomial of Equation 168-k is designated k'th sub-matrix Hk. Next, an LDPC-CC of a time varying period of 3g is considered that is generated from first sub-matrix Hi, second sub-matrix H2, third sub-matrix H3, ..., and 3g'th sub-matrix H3g. In Equations 168-1 through 1 68-3 g, combinations of orders of X1(D), X2(D) Xn-l(D), and P(D) satisfy the following condition. (a#i,i,i%3, a#i,i,2%3, a#i,i,3%3), (a#i,2,i%3, a#i,2,2%3, a#i,2,3%3), ..., (a#i,p,i%3, a#i,p,2%3, a#i,Pi3%3), ..., ( a#i,„-i.i%3, a#i,„.i,2%3, a#i,n-i.3%3), (b#i,i%3, b#i,2%3, b#i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ..., , n-1) and (a#2.i,i%3, a#2,1,2%3, a#2,1,3%3), (a#2,2,1%3, a#2,2,2%3, a#2,2,3%3), ..., (a#2,P,i%3> a#2,p,2%3, a#2,p,3%3), ..., (a#2,n-i ,i %3, a#2,a.i.2%3, a#2,n-i(3%3), (b#2,i%3, b#2,2%3, b#2,3°/°3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, l),or (2, 1, 0) (where p=l, 2, 3, ..., , n-1) and (a#3,i.i%3, a#3,i,2%3, a#3,i,3%3), (a#3,2,i%3, a#3,2,2%3, a#3,2,3%3), ..., , (a#3iP,i%3, a#3,P,2%3, a#3,P,3%3), ..., , (a#3,n-i,l%3, a#3,n-i,2%3, a#3,„.i,3%3), (b#3,i%3, b#3,2%3, b#3,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ..., , n-1) and • • and (a#k>i,i%3, a#ic,i,2%3, a#k>i,3%3), (a#k,2,i%3, a#k,2>2%3, a#k,2,3%3), ..., , (a#k,p,i%3, a#k,P,2%3, a#k,P,3%3), ..., (a#k,n-i.i%3, a#k,n-t,2%3, a#k,B.i>30/o3), (b#k>i%3, b#k>2%3, b#k,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ..., n-l)(where, k=l, 2, 3, ..., 3g) and • and (a#3g-2,i,i%3, a#3g.2(i?2%3, a#3g-2,i,3%3), (a#3g.2,2,i%3, a#3g-2,2,2%3, a#3g.2,2,3%3), ..., (a#3g-2,p,l%3, a#3g.2,p,2%3, a#3g-2,p,3%3), ..., (a#3g.2,n-l,l%3, a#3g.2,n-l,2%3, a#3g_2,n-l,3%3), (b#3g-2,i%3, b#3g-2,2%3, b#3g-2,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ..., n-1) and (a#3g-i,i,i%3, a#3g.i,i,2%3, a#3g-i,i,3%3), (a#3E-i,2,i%3, a#3g-i,2,2%3» a#3g-i,2,3%3), ..., (a#3e.i)P,i%3, a#3g-i ,p,2%3, a#3g-I,p,3%3), ..., (a#3g-1,n-1,J%3, a#3g-l,n-l,2%3, a#3g-l,n-l,3%3), (b#3g.i,i%3? b#3g-i,2%3, b#3g-i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ..., , n-1) and (a#3g,i,i%3, a#3g)i,2%3, a#3g,i,3%3), (a#3g>2,i%3, a#3g,2,2%3, a#3g,2,3%3), ..., (a#3g>P,i%3, a#3g,P<2%3, a#3g,p,3%3), ..., n-l,2%3, a#3g>n.ii3%3), (b#3gjio/„3, b#3g,2%3, b#3g>3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ..., , n-1) As also stated elsewhere than in this embodiment, taking ease of performing encoding into consideration, it is desirable for one "0" to be present among the three items (b#k,i%3, b#k,2%3, b#k,3%3) (where k=l, 2, ..., 3g) in Equations 168-1 through 168-3g. Also, in order to provide relevancy between parity bits and data bits of the same point in time, and to facilitate a search for a code having high correction capability, it is desirable for: one "0" to be present among the three items (a#k,i,i%3, a#k,i,2%3, a#k,i,3%3); one "0" to be present among the three items (a#k,2,i%3, a#k,2,2%3, a#k,2,3%3); • one "0" to be present among the three items (a#t,P,i%3, a#k,P)2%3, a#k,p,3%3); • and one "0" to be present among the three items (a#k,n-i,i%3, a#k, n.,,2%3, a#k, „.i,3%3), (where k=l, 2, ..., 3g). Next, an LDPC-CC of a time varying period of 3g (where g = 2, 3, 4, 5, ...) that takes ease of encoding into account is considered. At this time, if the coding rate is (n-l)/n (where n is an integer of 2 or above), LDPC-CC parity check polynomials can be represented as shown below. [ 1701 At this time, X1(D), X2(D), ..., Xn-l(D) are polynomial representations of data (information) XI, X2, ..., Xn-1, and P(D) is polynomial representation of parity. Here, in Equations 170-1 through I 70-3%, parity check polynomials are assumed such that there are three terms in X1(D), X2(D), ..., Xn-l(D), and P(D) respectively. In an LDPC-CC of a time varying period of 3g and a coding rate of (n-l)/n (where n is an integer of 2 or above), parity and information of time i are represented by Pi and Xj.i, Xi,2, ••-, Xj,n-i respectively. If i%3g = k (where k = 0, 1, 2, ..., 3g-l) is assumed at this time, a parity check polynomial of Equation 170-(k+l) holds true. For example, if i = 2, i%3 = 2 (k = 2), and therefore Equation 171 holds true. [171] ... (Equation 171) If and are satisfied at this time, the possibility of being able to create a code having higher error correction capability is increased. In Equations 170-1 through 170-3g, combinations of orders of X1(D), X2(D), ..., Xn-l(D), and P(D) satisfy the following condition. (a#,,i,i%3, an.i.2%3, a#i,i.3%3), (a#i,2,i%3, a#i,2>2%3, a#i,2,3%3), ..., (a#i,Pii%3, a#i,p,2%3, a# i,„,3%3), ..., (a# i,„_i,i%3, a#x,»-i.2%3s a#i,„.i.3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ... , n-1) and (a#2,i,i%3, a#2.i,2%3, a#2,i,3%3), (a#2,2>l%3, a#2>2,2%3, a#2,2,3°/o3), ..., (a#2,p,i%3, a#2,P)2%3, a#2>1)>3%3), ..., (a#2.n-i,i%3, a#2,n-i,2%3, a#2,n-i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ... , n-1) and (a#3,i,i%3, a#3,i,2%3, a#3,i,3%3), (a#3,2,i%3, a#3,2,2°/o3, a#3,2,3%3), ..., (a#3.p,i%3, a#3,p.2%3, a#3.p>3%3), ..., (a#3,n-i.i%3, a#3,n-i,2°/o3, a#3,„.,,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ... , n-1) and and (a#k,i,i°/o3, a#k,i,2%3, a#k,i,3%3), (a#k>2>i%3, a*k,2>2%3, a#k>2,3%3), ..., (a#k>p,i%3, a#k,p,2%3, a#k,P,3%3), ..., (a#k,n-i,i%3, a#k,n.[,2%3, a#kin-i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ... , n-l)(where, k=l, 2, 3, ... , 3g) and and (a#3g-2,i,i%3, a#3g.2,i,2%3, a#3g.2,i,3%3), (a#3g-2,2,i%3, a#3g-2,2,2%3, a#3g-2.2.3%3), ..., (a#3g-2,p,l%3, a#3g-2,P,2°/o3, a#3g-2,P,3%3) (a#3g.2,n-i,i%3, a#3g-2,n-i,2%3, a#3g.2(n-1,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ... , n-1) and (a#3g-i,i,i%3, a#3g-1,1,2%3, a#3g.1,1,3%3), (a#3g-1,2,1 %3 , a#3g-i,2,2%3, a#3g-i,2,3%3), ..., (a#3j!-i,p,i0/o3> a#3g-i,p,2%3, a#3g-i,p,3%3), ..., (a#3g.i>n.]ii%3, a#3g- i,n-i,2%3, a#3g-i,n-1,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ... , n-1) and (a#3g,i,i%3, a#3g,i,2%3, a#3g,i,3%3), (a#3g,2,i%3, a#3g>2,2%3, a#3g,2,3%3), ..., (a#3gjP>i%3, a#3g>Pj20/°3, a#3g,P>3%3) (a#3g,n-i,i%3, a#3g,n-i,2%3, a#3E>n.lt3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where p=l, 2, 3, ... , n-1) In Equations 170-1 through l70-3g, combinations of orders P(D) satisfy the following condition. (b#i,i%3, b#,,2%3), (bS2>1%3, b#2,2%3), (b#3.i%3, b#3,2%3), ..., (b#k.i%3, b#k)2%3), ..., (b#3g.2,i%3, b#3g-2,2°/o3), (b#3g-i,i%3, b#3g-i,2%3), (b#3g,i%3, b#3g>2%3) are any of (1, 2), or (2, 1) (where lc=l, 2, 3, ..., 3g) has a similar relationship with respect to Equations 170-1 through 170-3g as has with espect to Equations 168-1 through 168-3g. If the condition below () is added for Equations 170-1 through 170-3g in addition to , the possibility of being able to create an LDPC-CC having higher error correction capability is increased. The following condition is satisfied for orders of P(D) of Equations 170-1 through 170-3g. All values other than multiples of 3 {that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (b#,,,%3g, b#i,2%3g), (b#2,i%3g, b#2>2%3g), (b#3,i%3g, b#3,2%3g), ..., {b#k,i%3g, b#k,2%3g), ..., (b#3g-2,i%3g, b*3e-2,2%3g), (b#3g-i,i%3g, b#3g-i,2%3g), (b#3g,i%3g, b#3g,2%3g). The possibility of obtaining good error correction capability is high if there is also randomness while regularity is maintained for positions at which "l"s are present in a parity check matrix. With an LDPC-CC for which the time varying period is 3g (where g = 2, 3, 4, 5, ...) and the coding rate is (n-l)/n (where n is an integer of 2 or above) that has parity check polynomials of Equations 170-1 through 170-3g, if a code is created in which is applied in addition to it is possible to provide randomness while maintaining regularity for positions at which "l"s are present in a parity check matrix, and therefore the possibility of obtaining good error correction capability is increased. Next, an LDPC-CC of a time varying period of -3g (where g = 2, 3, 4, 5, ...) is considered that enables encoding to be performed easily and provides relevancy to parity bits and data bits of the same point in time. At this time, if the coding rate is (n-l)/n (where n is an integer of 2 or above), LDPC-CC parity check polynomials can be represented as shown below. [172] ... (Equation 172-3g) At this time, X1(D), X2(D), ..., Xn-l(D) are polynomial representations of data (information) XI, X2, ..., Xn-1, and P(D) is polynomial representation of parity. In Equations 172-1 through 172-3g, parity check polynomials are assumed such that there are three terms in X1(D), X2(D), ..., Xn-l(D), and P(D) respectively, and a D° term is present in X1(D), X2(D), ..., Xn-l(D), and P(D), (where k=l, 2, 3, .... 3g). In an LDPC-CC of a time varying period of 3g and a coding rate of (n-l)/n (where n is an integer of 2 or above), parity and information of time i are represented by Pi and Xj,i, Xij2, •■■, Xj.n-i respectively. If i%3g = k (where k = 0, 1, 2, ... 3g-l) is assumed at this time, a parity check polynomial of Equation 172-(k+l) holds true. For example, if i = 2, i%3g = 2 (k = 2), and therefore Equation 173 holds true. [173] ... (Equation 173) If and are satisfied at this time, the possibility of being able to create a code having higher error correction capability is increased. In Equations 172-1 through 172-3g, combinations of orders of X1(D), X2(D), ..., Xn-l(D), and P(D) satisfy the following condition. (a#ipi,i%3, a#,,i)2%3), (a#i.2,i%3, a#i,2,2%3), ..;, (a#i,p.i%3, a#i,p,2°/o3), ..., (a#i,„.i,i%3, a#i,n-i,2%3) are any of (1, 2), (2, 1) (p=l, 2, 3, .-.., n-1) and (a*2,i,i°/o3, a#2,i,2%3), (a#2,2.i%3, a#2,2,2%3), ..., (a#2,P,i%3, a#2,p,2%3), ..., (a#2,„.i,i%3, a#2,n-i,2%3) are any of (1, 2), or (2, 1) (where p=l, 2, 3, ..., n-1) and (a#3,i,i%3, a#3,i,2%3), (a#3.2.i%3, a#3,2,2%3), ..., (a#3,P,i%3, a#3,P,2%3), ..., (a#3,n-i,i%3, a#3)„-ij2%3) are any of (1, 2), or (2, 1) (where p=l, 2, 3, ..., n-1) and and (a#k,i,i%3, a#ICjit2%3), (a#kj2,i%3, a#k2,2%3), ..., (a#k,p,i%3, a#k,P,2%3), ..., (a#k,n-i,i%3, a#k,n-i,2%3) are any of (1, 2), or (2, 1) (where p = l, 2, 3, ..., n-l)(where, k=l, 2, 3, .... 3g) and • • and (a#3g-2,i,i%3, a#3g-2,i,2%3), (a#3g-2,2,i%3, a#3g-2,2,2%3)) ..., (a#3g-2,P>i%3, a#3g-2,p,2%3), ..., (a#3g-2,n-i,i%3, a#3g-2,n-t,2%3) are any of (1, 2), or (2, 1) (where p=l, 2, 3, ..., n-1) and (a#3g-i,i,i°/o3, a#3g.i,i,2%3)v (a#3g-i,2,i%3, a#3g-i,2,2%3), ..., (a#3g-i,P)i%3, a#3g-i,p,2%3), ..., (a#3g.i,n-i,i%3, a#3g.i,n.i,2%3) are any of (1, 2), or (2, 1) (where p=l, 2, 3, ..., n-1) and (a#3g,i,i%3, a#3g)i,2%3), (a#3g,2.i%3, a#3g,2>2%3), (a#3g,P,i%3, a#3g,pj2%3), ..., (a#3g,n-i,i%3, a#3g>n-t,2%3) are any of (I, 2), or (2, 1) (where p=l, 2, 3, ..., n-1) In Equations 172-1 through l?2-3g, combinations of orders of P(D) satisfy the following condition. (b#i,i%3, b#ij2%3), (b*2,i°/o3, b#2,2%3), (b#3.i%3, b#3,2%3), ..., (b#k,i%3, b#k,2%3), ..., (b#3g-2,l%3, b#3g-2,2%3), (b#3g.i,i%3, b#3g-l,2%3), (b#36,l%3, b#3g,2%3) are any of (1, 2), or (2, 1) (where k=l, 2, 3, ..., 3g) has a similar relationship with respect to Equations 172-1 through 172-3g as has with respect to Equations 168-1 through 168-3g. If the condition below () is added for Equations 172-1 through 172-3g in addition to t the possibility of being able to create a code having high error correction capability is increased. The following condition is satisfied for orders of X1(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (a«i,i,i%3g, a#i,i,2%3g), (a#2>i,i%3g, a#2,i,2%3g), ..., (a#p,i,i%3g, a#p,i,2%3g), ..., (a#3g)i, t%3g, a#3g,i>2%3g) (where p=l, 2, 3 3g) and The following condition is satisfied for orders of X2(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (a«i,2,i%3g, a#is2,2%3g), (a#2,2,i%3g, a#2,2,2%3g), ..., (a#p,'2,i%3g, a#p,2,2%3g), ..., (aa3g,2,i%3g, a#3gf2,2°/o3g) (where p = l, 2, 3 3g) and The following condition is satisfied for orders of X3(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-1) are present in the following 6g values: (a#i,3,i%3g, a#i,3,2%3g), (a#2.3.i%3g, a*2,3,2%3g), ..., (a#p,3,i%3g, a#p>3(2%3g), .... (a#3g,3,i%3g, a#3g>3,2%3g) (where p=l, 2, 3, ..., 3g) and • and The following condition is satisfied for orders of Xk(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-1) are present in the following 6g values: (a#i,k,i%3g, a#I>k,2%3g), (a#2ik>i%3g, a#2ik>2%3g), ..., (a#p,k,i%3g, a#Ptk,2°/o3g), ..., (a#3gik, 1 %3g, a#3gik,2%3g) (where p = l, 2, 3, ..., 3g) (where k=l, 2, 3, ..., n-1) and and The following condition is satisfied for orders of Xn-l(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (a*i>n-i,i%3g, a*i,n-i,2%3g), (a#2,n-i,i%3g, a#2,n-i,2°/o3g), ..., (a#p,„.i,i%3g, a#PjI1-i,2%3g), ..., (a#3g>n-i,i%3g, a#3gjn-i,2%3g) (where p=l, 2, 3, ..., 3g) and The following condition is satisfied for orders of P(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (b#i,,%3g, b#i,2%3g), (b#2,i%3gs b#2,2%3g), (b#3>!%3g, b#3,2%3g), ..., (b#k,i%3g, b#k,2%3g), ..., (b#3g_2>1%3g, b#3g-2,2%3g), (b#3g;i,i%3g, b#3e.1>2%3g), (b#3g,i%3g, b#3g<2%3g) (where k=l, 2, 3, ..., n-1) The possibility of obtaining good error correction capability is high if there is also randomness while regularity is maintained for positions at which "l"s are present in a parity check matrix. With an LDPC-CC for which the time varying period is 3g (where g = 2, 3, 4, 5, ...) and the coding rate is (n-l)/n (where n is an integer of 2 or above) that has parity check polynomials of Equations 172-1 through 172-3g, if a code is created in which is applied in addition to it is possible to provide randomness while maintaining regularity for positions at which "l"s are present in a parity check matrix, and therefore the possibility of obtaining good error correction capability is increased. The possibility of being able to create a code having higher error correction capability is also increased if a code is created using instead of , that is, with added in addition to . The following condition is satisfied for orders of X1(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (a#i,i,i%3g, a#i,i,2%3g), (a#2,i,i%3g, a#2,i,2%3g), ..., (a#p,i,i%3g, a#P)i>2%3g), ..., (a#3g>1, 1 %3g, a#3g)i,2%3g) (where p=l, 2, 3, ..., 3g) or The following condition is satisfied for orders of X2(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-1 (0, I, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (a#i,2,i%3g, a#i,2,2%3g), (a#2,2,i%3g, a#22j2%3g), ..., (a#p,2,i%3g, a#p>2>2%3g), .-., (a#3B.2,i%3g, a#3g>2,2%3g) (where p=l, 2, 3, ..., 3g) or The following condition is satisfied for orders of X3(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ,.., 3g-2, 3g-l) are present in the following 6g values: (a#i,3,i%3g, a»i,3,2%3g), (a#2,3,i%3g, a#2j3>2%3g), ..., (a#pj3,i%3g, a#p,3,2%3g), ..., (a#3g>3,i%3g, a#3g,3,2%3g) (where p=l, 2, 3, ..., 3g) or • or The following condition is satisfied for orders of Xk(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (a#i,k,i%3g, a#i,k,2%3g), (a#2,fc,i%3 g, aS2,k,2%3g), ..., (a#p,k,i%3g, a#Pjk)2%3g), ..., (a#3g,k>i%3 g, a#3g>k,2%3g) (where p=l, 2, 3, ..., 3g) (where k=l, 2, 3, ..., n-1) or • or The following condition is satisfied for orders of Xn-l(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-1) are present in the following 6g values: (a#i,n-i.i%3g, a#i,n-1,2%3g), (a#2,n-i,i%3g, a#2,n-l,2%3g), ..., (a#p,n-l,l%3g, a#p,n-l,2%3g), ..., (a#3g,n-l,l%3g, a#3g,n-i,2%3g) (where p=l, 2, 3, ..., 3g) or The following condition is satisfied for orders of P(D) of Equations 172-1 through 172-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-1) are present in the following 6g values: (b#i,i%3g, b#i,2%3g), (b#2,i%3g, b#2j2%3g), (b#3>i%3g, b#3,2%3g) (b*fc>1%3g, b#k>2%3g), ..., (b#3g.2>1%3g, b#3g.2,2%3g), (b#3g-i,i%3g, b#3g-i,2%3g), (b#3g,i%3g, b#3e,2%3g) (where k=l, 2, 3, .-, 3g) The above description relates to an LDPC-CC of a time varying period of 3g and a coding rate of (n-l)/n (where n is an integer of 2 or above). Below, conditions are described for orders of an LDPC-CC of a time varying period of 3g and a coding rate of 1/2 (n = 2). Consider Equations 174-1 through 174-3g as parity check polynomials of an LDPC-CC for which the time varying period is 3g (where g=l, 2, 3, 4, ...) and the coding rate is 1/2 (n = 2). [174] ... (Equation 174-3g) At this time, X is polynomial representation of data (information)X and P(D) is polynomial representation of parity. Here, in Equations 174-1 through 174-3g, parity check polynomials are assumed such that there are three terms in X(D) and P(D) respectively. Thinking in the same way as in the case of an LDPC-CC of a time varying period of 3 and an LDPC-CC of a time varying period of 6, the possibility of being able to obtain higher error correction capability is increased if the condition below () is satisfied in an LDPC-CC of a time varying period of 3g and a coding rate of 1/2 (n = 2) represented by parity check polynomials of Equations 174-1 through 174-3g. In an LDPC-CC of a time varying period of 3g and a coding rate of 1/2 (n = 2), parity and information of time i are represented by Pi and Xi,i respectively. If i%3g = k (where k = 0, 1, 2, ..., 3g-l) is assumed at this time, a parity check polynomial of Equation 174-(k+l) holds true. For example, if i = 2, i%3g = 2 (k = 2), and therefore Equation 175 holds true. [175] \jf#+Jf##]f#)X#Ajr#jf#+]f#P# ... (Equation 175) In Equation 174-1 through 174-3g, it is assumed that a#k,i,i, a#k,i,2, and a#k,i,3 are integers (where a#k,i,i#a#k,i,2#a#k,i,3). Also, it is assumed that b#k,i, b#k,2, and b#k,3 are integers (where btfk.i#bak#btfk.s). A parity check polynomial of Equation 174-k (k=l, 2, 3, ..., 3g) is called "check equation #k,- and a sub-matrix based on a parity check polynomial of Equation 174-k is designated kth sub-matrix Hk. Next, an LDPC-CC of a time varying period of 3g is considered that is generated from first sub-matrix Hi, second sub-matrix H2, third sub-matrix H3 and 3g'th sub-matrix H3g In Equations 174-1 through 174-3g, combinations of orders of X(D) and P(D) satisfy the following condition. (a»i,i,i«3, a#i,i,2%3, «#i.i,3%3), i%3,b#2>2%3 ,b#2,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) and (a#3,i,i%3, a#3.i,2°/o3, a#3.i,3%3), (b#3,i0/°3,b#3,2%3,b#3,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) and • and (a#k,i,i0/o3,a#fc,i,20/o3,a#k,i.30/o3),(b#k,1%3,b#k.2%3,b#t,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where k=l, 2, 3, ..., 3g), and • and (a#3g-2,i,i%3,a#3g.2,i,2%3,a#3g-2.i»3%3),(b#3g-2,i%3,b#3g-2,2 %3,b*3s-2,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) and (a#3g-1,1,1 %3 ,a#3g. 1,1,2%3 ,a#3g-1,1,3 % 3 ),(b#3g-1,1 %3 ,b#3g-1,2% 3,b#3g-i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) and (a#3g,i,i%3,a#3g,i,2%3,a#3g>i)3%3),(b#3g)i%3,b#3g,2%3,b#3gj3 %3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) As also stated elsewhere than in this embodiment, taking ease of performing encoding into consideration, it is desirable for one "0" to be present among the three items (b#k,i%3, b#k,2%3, and b#k,3%3) (where k=l, 2, ..., 3g) in Equations 174-1 through 174-3g. Also, in order to provide relevancy between parity bits and data bits of the same point in time, and to facilitate a search for a code having high correction capability, it is desirable for one "0" to be present among the three items (a#k,i,i%3, a#k,i,2%3, and a#k,i,3%3); Next, an LDPC-CC of a time varying period of 3g (where g = 2, 3, 4, 5, ...) that takes ease of encoding into account is considered. At this time, if the coding rate is 1/2 (n = 2), LDPC-CC parity check polynomials can be represented as shown below. At this time, X(D) is polynomial representation of data (information)X and P(D) is polynomial representation of parity. Here, in Equations 176-1 through 176-3g, parity check polynomials are assumed such that there are three terms in X(D) and P(D) respectively. In an LDPC-CC of a time varying period of3g and a coding rate of 1/2 (n = 2), parity and information of time i are represented by Pi and Xj.i respectively. If i%3g = k (where k = 0, 1, 2, ..., 3g-l) is assumed at this time, a parity check polynomial of Equation 176-(k+l) holds true. For example, if i = 2, i%3g = 2 (k = 2), and therefore Equation 177 holds true. [177] If and are satisfied at this time, the possibility of being able to create a code having higher error correction capability is increased. In Equations 176-1 through 176-3g, combinations of orders of X(D) satisfy the following condition. (a#i,i,i%3, a#i,i,2%3, a#I,,,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) and (a*2,i,i°/o3, a#2,i,2%3, a#2,i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) and (a#3,i.i°/o3, a#3.i,2%3, a#3,,,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) and (a#k,i,i%3,a#k>i,20/o3,a#k,i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) (where k=l, 2, 3, ..., 3g), and • and (a#3g-2,i,i%3,a#3g-2,i,2%3,a#3g-2,i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) and (a#3g-i,i,i%3,a#3g-!,i,2%3,a#3g-i,i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) and (a#3g,i,i%3,a#3E,i,2%3Ja#3g,i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0) [0770] In Equations 176-1 through 176-3g, combinations of orders of P(D) satisfy the following condition. (b#i,i%3, b#i,2%3), (b#2,i%3, b#2,2%3), (b*3>i%3, b*3,2%3), ...s (b#k,i%3, b#k,2%3), ..., (b#3g-2,i%3, b#3g-2,2%3), (b#3g.i,i%3, b#3g-i,2%3), (b#3gji%3, b#3g,2%3) are any of (1, 2), or (2, 1) (k=l, 2, 3, ..., 3g) has a similar relationship with respect to Equations 176-1 through 176-3g as has with respect to Equations 174-1 through 174-3g. If the condition below () is added for Equations 176-1 through 176-3g in addition to , the possibility of being able to create an LDPC-CC having higher error correction capability is increased. The following condition is satisfied for orders of P(D) of Equations 176-1 through 176-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (b#i,i%3g, b*i,2%3g), (b#2,i%3g, b#2,2%3g), (b#3>i%3g, b#3,2%3g), ..., (b#k,i%3g, b#k,2%3g), ..., (b#3g-2,i%3g, b#3g-2J2%3g), (b#3g-i,i%3g, b#3g.i,2%3g), (b#3g,i%3g, b#3g,2%3g). The possibility of obtaining good error correction capability is high if there is also randomness while regularity is maintained for positions at which "l"s are present in a parity check matrix. With an LDPC-CC for which the time varying period is 3g (where g = 2, 3, 4, 5, ...) and the coding rate is 1/2 (n = 2) that has parity check polynomials of Equations 176-1 through 176-3g, if a code is created in which is applied in addition to it is possible to provide randomness while maintaining regularity for positions at which "l"s are present in a parity check matrix, and therefore the possibility of obtaining better error correction capability is increased. Next, an LDPC-CC of a time varying period of 3g (where g = 2, 3, 4, 5, ...) is considered that enables encoding to be performed easily and provides relevancy to parity bits and data bits of the same point in time. At this time, if the coding rate is 1/2 (n = 2), LDPC-CC parity check polynomials can be represented as shown below. [178] At this time, X(D) is polynomial representation of data (information) X and P(D) is polynomial representation of parity. In Equations 178-1 through 178-3g, parity check polynomials are assumed such that there are three terms in X(D) and P(D) respectively, and a D° term is present in X(D) and P(D), (where k=l, 2, 3, ..., 3g). In an LDPC-CC of a time varying period of 3g and a coding rate of 1/2 (n = 2), parity and information of time i are represented by Pi and Xj,i respectively. If i%3g = k (where k = 0, 1, 2, ..., 3g-l) is assumed at this time, a parity check polynomial of Equation 178-(k+l) holds true. For example, if i = 2, i%3g = 2 (k = 2), and therefore Equation 179 holds true. [179] If and are satisfied at this time, the possibility of being able to create a code having higher error correction capability is increased. In Equations 178-1 through 178-3g, combinations of orders of X(D) satisfy the following condition. (a#i,i,i%3, a#i,i.2%3) is (1, 2) or (2, 1), and has a similar relationship with respect to Equations 178-1 through 178-3g as has with respect to Equations 174-1 through 174-3g. If the condition below () is added for Equations 178-1 through 178-3g in addition to , the possibility of being able to create an LDPC-CC having higher error correction capability is increased. The following condition is satisfied for orders of X(D) of Equations 178-1 through 178-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (a#i,i,i%3g, a«i,i,2%3g), (a#2,i,i%3g, a#2,i,2%3g), ..., (a#Pjl>i%3g, a#p,ii2%3g), ..., (a#3g>,,, %3g, a#3g.i.2%3g) and the following condition is satisfied for orders of P(D) of Equations 178-1 through 178-3g. All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (b#i,i%3g, b#1,2%3g), (b#2,i%3g, b#2,2%3g), (b#3,i%3g, b#3,2%3g), ..., (b*k>i%3g, b#k,2%3g), ..., (b#3g-2,i%3g, b#3g.2i2%3g), (b#3g-i,i%3g, b#3g.i>2%3g), (b#3g,i%3g, b#3g,2%3g) (where k=l, 2, 3, ... 3g) The possibility of obtaining good error correction capability is high if there is also randomness while regularity is maintained for positions at which "l"s are present in a parity check matrix. With an LDPC-CC for- which the time varying period is 3g (where g = 2, 3, 4, 5, ...) and the coding rate is 1/2 that has parity check polynomials of Equations 178-1 through 178-3g, if a code is created in which is applied in addition to , it is possible to provide randomness while maintaining regularity for positions at which "l"s are present in a parity check matrix, and therefore the possibility of obtaining better error correction capability is increased. The possibility of being able to create a code having higher error correction capability is also increased if a code is created using instead of , that is, with added in addition to . The following condition is satisfied for orders of X(D) of Equations 178-1 through 178-3g: All values other than multiples of 3 (that is, 0, 3, 6, ..., 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (an,i,i%3g, a#i,i,2%3g), (a#2,i,i%3g, a#2,i,2%3g), ..., (a#p,i,i%3g, a#P>i,2°/o3g), ..., (a#3g,i,i%3g, a#3g,i,2%3g), (where p=l, 2, 3, ..., 3g); or the following condition is satisfied for orders of P(D) of Equations 178-1 through 178-3g: All values other than multiples of 3 (that is, 0, 3, 6 3g-3) from among integers from 0 to 3g-l (0, 1, 2, 3, 4, ..., 3g-2, 3g-l) are present in the following 6g values: (b#i,i%3g, b#i)2%3g), (b#2,i%3g, b#2,2%3g), (b#3,i%3g, b#3,2°/o3g), ..., (b#kj,%3g, b#k,2%3g), ..., (b#3g-2.i°/o3g, b#3g-2,2%3g), (b#3g-i,i%3g, b#3g.12%3g), (b#3g,i%3g, b#3g,2%3g), (where k=l, 2, 3, ..., 3g). Examples of LDPC-CCs of a coding rate of 1/2 and a time varying period of 6 having good error correction capability are shown in Table 9. [Table 9] Code Parity Check Polynomials LDPC-CC#lof time varying period of 6 and coding rate 1/2 "Check polynomial #1" "Check polynomial #2" "Check polynomial #3" "Check polynomial #4" "Check polynomial #5" "Check polynomial #6" (Zj328+£>3n+j)x(D)++D*6l+l)piDrHD2S«+D41+1)p(D>=0 (£»w+ZJ40+l)X(O)+(Z)316+Z)71+l)P(D)=0 {£?™+Dm+1 )X(Dy+{L?15+Dn6+1 )Ptf>H> LDPC-CC #2 of time varying period of 6 and coding rate 1/2 "Check polynomial #1" "Check polynomial #2" "Check polynomial #3" "Check polynomial #4" "Check polynomial #5" "Check polynomial #6" (Z>524+ZrM1+l)X(Z)>++Ki)5ro+Z)!n2+l)P(D)-0 (D*01+D/55+l)X(D)*iI>t43+D1O6+1 )P(Z>H> 0ai+EP9S+1 )XtfjWZ>W4+Z>,00+1 )PH> {Z)136+Z)S9+1 )x(/J)+(jC>599+DJ59+ , )p(/))=0 LDPC-CC #3 of time varying period of 6 and coding rate 1/2 "Check polynomial # 1" "Check polynomial #2" "Check polynomial #3" "Check polynomial #4" "Check polynomial #5" "Check polynomial #6" (D2S3+D44+1 )x+(D''73+D256+ l)P(D)-o (Z)595+Z)]43+1)X(D)+592+Z)49'+1 )P(D)=0 (p50+£(10+ j mp#W+j,! 12+ J )p(£))=0 (£>286+Z)221+j )x(D)+(Z)Sn+Zj359+ j )p(z))=!0 (Z,407+Z)322+ j )x(DwZyS3+Z)2«+ ] )p(D)=o (Another Embodiment 16) In Another Embodiment 9, an LDPC-CC of a time varying period of 2 providing good received quality was described. Here, an LDPC-CC of a time varying period of 2 providing good received quality to which another Embodiment 14 is additionally applied will be described. A case in which the coding rate is (n-l)/n (where n is an integer of 2 or above) is described below as an example. Consider Equation 180-1 and Equation 180-2 as parity check polynomials of an LDPC-CC for which the time varying period is 2. At this time, X1(D), X2(D), ..., Xn-l(D) are polynomial representations of data (information) XI, X2, ..., Xn-1, and P(D) is polynomial representation of parity. Here, in Equation 180-1 and Equation 180-2, parity check polynomials are assumed such that there are three terms in X1(D), X2(D), ..., Xn-l(D), and P(D) respectively. In Equation 180-1, it is assumed that at, 1, a*,2, and ai,3 (i=l, 2, ..., n-1) are integers (where a#i#ai#a#). Also, it is assumed that bl, b2, and b3 are integers (where bl#b2#b3). A parity check polynomial of Equation 180-1 is called "check equation #1," and a sub-matrix based on a parity check polynomial of Equation 180-1 is designated second sub-matrix Hi. In Equation 180-2, it is assumed that Ai.i, Aj,2, and Aj,3 (where i=l, 2, ..., n-1) are integers (where AjFi#Ai,2#Ai,3). Also, it is assumed that Bl, B2, and B3 are integers (where B1#B2#B3). A parity check polynomial of Equation 180-2 is called "check equation #2," and a sub-matrix based on a parity check polynomial of Equation 180-2 is designated second sub-matrix H2. Next, an LDPC-CC of a time varying period of 2 generated from first sub-matrix Hi and second sub-matrix H2 is considered. If the following conditions apply in Equation 180-1 and Equation 180-2, the conditions described in another Embodiment 14 are satisfied, and therefore a loop 6 never occurs, and a regular LDPC code is formed, enabling good error correction capability to be obtained: "For X1(D) related coefficients (ai,i, ai,2, ai,3> and coefficients (Aij, Ai,2, AIJ), one of the following is satisfied: • Of (a 1,1, ai(2, a 1 f3), two are odd numbers and one is an even number, and of (Ai,i, Ai#, A13), two are odd numbers and one is an even number • Of (ai,i, ai#, ai,3), one is an odd number and two are even numbers, and of (Ai,i, Ai,2, A13), one is an odd number and two are even numbers" and "For Xi(D) (where i = 2, 3, ..., n-1) related coefficients (aifi, ai,2, ai(3) and coefficients (Aj,i, Aii2, Aij3), one of the following is satisfied: • Of (ai,i, aj,2, aj,3), two are odd numbers and one is an even number, and of (Aj,i, Aj,2, Aj#), two are odd numbers and one is an even number • Of (a;,i, aj,2, aj>3), one is an odd number and two are even % numbers, and of (Aj,i, Aii2, Ai>3), one is an odd number and two are even numbers" and "One of the following is satisfied: • Of (bi, b2, b3), two are odd numbers and one is an even number, and of (Bi, B2, B3), two are odd numbers arid one is an even number • Of (bi, b2, b3), one is an odd number and two are even numbers, and of (Bi, B2, B3), one is an odd number and two are even numbers." (Another Embodiment 17) In another Embodiment 15, an LDPC-CC of a time varying period of 3 providing good received quality was described. Here, a puncturing method suitable for the LDPC-CC of a time varying period of 3 described in another Embodiment 15 will be described. A case in which a code of a coding rate of 1/2 (a coding rate of 1/2) is made larger than a coding rate of 1/2 by means of puncturing will be described as an example. Consider an LDPC-CC of a time varying period of 3 defined by Equations 162-1 through 162-3. At this time, generality is not lost even if al>a2>a3, bl>b2>b3, A1>A2>A3, B1>B2>B3, al>a2>a3, and pl>p2>p3. Thus, the following description is based on these relationships. The maximum order of information X(D) of "check equation #1" of Equation 162-1 is al, and the maximum order of parity P(D) is bl. The maximum order of information X(D)of "check equation #2" of Equation 162-2 is Al, and the maximum order of parity P(D) is Bl. The maximum order of information X(D) of "check equation #3" of Equation 162-3 is al, and the maximum order of parity P(D) is pi. Here, the following two conditions are given. [Condition #1] Consider an order that is the maximum value among maximum orders al, Al, and al of data X(D) in "check equation #1," "check equation #2," and "check equation #3." For example, if al is the largest among these three maximum orders, al related bits are not punctured, that is, al related bits are transmitted, and puncture (non-transmitted) bits are selected from bits other than al bits. Similarly, if Al is the largest among these three maximum orders, Al related bits are not punctured, and puncture bits are selected from bits other than Al bits. Likewise, if ctl is the largest among these three maximum orders, al related bits are not punctured, and puncture bits are selected from bits other than al bits. [Condition #2] Consider an order that is the maximum value among maximum orders bl, Bl, and pi of parity P(D) in "check equation #1," "check equation #2," and "check equation #3." For example, if bl is the largest among these three maximum orders, bl related bits are not punctured, that is, bl related bits are transmitted, and puncture (non-transmitted) bits are selected from bits other than bl bits. Similarly, if Bl is the largest among these three maximum orders, Bl related bits are not punctured, and puncture bits are selected from bits other than Bl bits. Likewise, if pi is the largest among these three maximum orders, pi related bits are not punctured, and puncture bits are selected from bits other than pi bits. Puncturing is performed on the LDPC-CC of a time varying period of 3 described in another Embodiment 15 so that either [Condition #1] or [Condition #2] above is satisfied. By this means, good error correction capability can be obtained even if puncturing is performed. Naturally, still better error correction capability can be obtained if [Condition #1] and [Condition #2] are both satisfied. A detailed description will be given below using accompanying drawings. FIG.68 shows a correspondence relationship of LDPC-CC parity check matrix H of a time varying period of 3, transmission sequence u, and parity patterns in accordance with above [Condition #1] and [Condition #2J. FIG.68 shows a case in which configuration is performed by means of the same kind of parity check polynomials as in FIG.67A as parity check polynomials of a time varying period of 3. Therefore, sub-matrices Hi, H2, and H3 in FIG.68 are the same as sub-matrices Hi, H2, and H3 in FIG.67A. If transmission vector u is represented as u=(Xi, Pi, X2, P2, ..., Xi, Pi, Xi+i, Pi+i, ...)T, the relationship Hu = 0 holds true. k Therefore, the relationship between a transmission sequence and parity check matrix is as shown in FIG.68, as described in Embodiment 7 (see FIG.18). In the LDPC-CC of a time varying period of 3 in FIG.68, of maximum orders (al, Al, i>ai,2>ai,3, bl>b2>b3, Ai,i>Aii2>Ai>3, B1>B2>B3, aif i>aij2>ai,3> and pi>p2>p3 (i=l,2, ..., n-1). Thus, the following description is based on these relationships. The maximum order information Xi(D) of "check equation #1 "of Equation 163-1 is a#i, and the maximum order of parity P(D) is bl. The maximum order of information Xi(D) of "check equation #2" of Equation 163-2 is Ai,i, and the maximum order of parity P(D) is Bl. The maximum order of information Xi(D) of "check equation #3" of Equation 162-3 is a#j, and the maximum order of parity P(D) is pi. Here, the following two conditions are given. [Condition #1] Consider an order that is the maximum value among maximum orders aitl, Aj.i, and cti(i of data Xi(D) in "check equation #1," "check equation #2," and "check equation #3." For example, if aj,i is the largest among these three maximum orders, ai,i related bits are not punctured, that is, aj,i related bits are transmitted, and puncture (non-transmitted) bits are selected from bits other than £ij j bits. Similarly, if A#i is the largest among these three maximum orders, Aj.j related bits are not punctured, and puncture bits are selected from bits other than Ai,i bits. Likewise, if a#i is the largest among these three maximum orders, ai(i related bits are not punctured, ai(i related bits are transmitted and puncture (non-transmitted) bits are selected from bits other than aji bits. [Condition #2] Consider an order that is the maximum value among maximum orders bl, Bl, and pi of parity P(D) in "check equation #1," "check equation #2," and "check equation #3." For example, if bl is the largest among these three maximum orders, bl related bits are not punctured, that is, bl related bits are transmitted, and puncture (non-transmitted) bits are selected from bits other than bl bits. Similarly, if Bl is the largest among these three maximum orders, Bl related bits are not punctured, Bl related bits are transmitted and puncture (non-transmitted) bits are selected from bits other than Bl bits. Likewise, if pi is the largest among these three maximum orders, pi related bits are not punctured, pi related bits are transmitted and puncture (non-transmitted) bits are selected from bits other than pi bits. Puncturing is performed on an LDPC-CC of a time varying period of 3 and a coding rate of (n-l)/n so that either [Condition #1] or [Condition #2] above is satisfied. By this means, good error correction capability can be obtained even if puncturing is performed. Naturally, still better error correction capability can be obtained if [Condition #1] and [Condition #2] are both satisfied. The setting method for preventing candidacy as puncture bits (non-transmitted bits) is as illustrated in FIG.68 and FIG.69. In another Embodiment 14, a method was described for eliminating a loop 6 that inevitably occurs in an LDPC-CC of an time varying period of 2. A description of a case in which the method described in another Embodiment 14 is applied to another embodiment forms another Embodiment 15. The important point in this case is the "remainder" related condition (remainder rule). That is to say, if a remainder rule is set properly, the inevitably occurring loop 6 described in another Embodiment 14 can be eliminated. In the description of LDPC-CCs of time varying periods 3 and 4 in another Embodiment 15, a remainder rule is set on the premise of eliminating an inevitably occurring loop 6, and a remainder rule for obtaining good data received quality has been described in detail. Also, remainder rules for obtaining good data received quality for LDPC-CCs of time varying periods of 6 and 3g based on time varying periods of 2, 3, and 4 remainder rules have been described. The present invention is not limited to the above-described embodiments, and various variations and modifications may be possible without departing from the scope of the present invention. For example, in the above embodiments a case has been described in which the present invention is implemented as a radio communication apparatus, but the present invention is not limited to this, and can also be applied in the case of implementation by means of power line communication. It is also possible for this communication method to be implemented as software. For example, provision may be made for a program that executes the above-described communication method to be stored in ROM (Read Only Memory) beforehand, and for this program to be run by a CPU (Central Processing Unit). Provision may also be made for a program that executes the above-described communication method to be stored in a computer-readable storage medium, for the program stored in the storage medium to be recorded in RAM (Random Access Memory) of a computer, and for the computer to be operated in accordance with that program. It goes without saying that the present invention is not limited to radio communication, and is also useful in power line communication (PLC), visible light communication, and optical communication. The disclosures of Japanese Patent Application No.2007-256567, filed on September 28, 2007, Japanese Patent Application No.2007-340963, filed on December 28, 2007, Japanese Patent Application No.2008-000844, filed on January 7, 2008, Japanese Patent Application No.2008-000847, filed on January 7, 2008, Japanese Patent Application No.2008-015670, filed on January 25, 2008, Japanese Patent Application No.2008-045290, filed on February 26, 2008, Japanese Patent Application No. 2008-061749, filed on March 11, 2008, and » Japanese Patent Application No.2008-149478, filed on June 6, 2008, including the specifications, drawings and abstracts, are incorporated herein by reference in their entirety. Industrial Applicability The present invention can be widely applied to communication systems that use an LDPC-CC. We Claim : , 1. An encoding method that creates a Low-Density Parity-Check Convolutional Code (LDPC-CC) of a time varying period of 3g (where g is a positive integer), the encoding method comprising: a step of supplying the first through 3g'th parity check polynomials, in an LDPC-CC defined based on, in a parity check polynomial represented by Equation 1-1, a first parity check polynomial, (a#i,i,i%3, a3%3), (a#t,2,i%3, a#i,2>2%3, a#i,2,3%3), ..., (a#i,n.i.i%3, a#i,„-i,2%3J a#i,n-i.3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and (b*i,i%3, b#,,2%3, b„i,3%3) is any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and a second parity check polynomial in which, in a parity check polynomial represented by Equation 1-2, (a#2,i,i%3, a#2,i,2%3, a#2,i,3%3), (a#2,2,i%3, a#2,2,2%3, a#2,2,3%3), ..., (a#2,n-i,i%3, a#2>n-i,2%3, a#2,n-i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and (b*2,i%3, b#2>2%3, b*2,3%3) is any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and a kk'th parity check polynomial in which, in a parity check polynomial represented by Equation 1-kk (where kk = 3, 4, ..., 3g-l), (a#kk,i,i%3, a#kk,i,2%3, a#kk,i,3%3), (a#kk,2,i%3, a#kk,2,2%3, a#kki2,3%3), ..., (a#kk,n-i,i%3, a*kk,n-i,2%3, a#kk,n.i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and (b*kk,,%3, b#kk,2%3, b#kk,3%3) is any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and a 3g'th parity check polynomial in which, in a parity check polynomial represented by Equation 1 -3 g, (a#3g) i, i %3 , a#36ii,2%3, a#3g,i.3%3), (a#3g.2,i%3, a#3g,2f2%3, a#3g,2,3%3), ..., (a#3g,n-i,i%3, a#3g,n-i,2%3, a#3g,n-i,3%3) are any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0), and (b#3g,i%3, b#3g>2%3, b*3g,3%3) is any of (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), or (2, 1, 0); and a step of acquiring an LDPC-CC codeword by linear computation using the first through 3g'th parity check polynomials and input data. [1] ••• (Equation 1-k) Where, Xi(D), X2(D), ..., X„-i(D) is an information sequence Xi, X2, ..-, X„.i polynomial representation (where n is an integer of 2 or above), and P(D) is a parity sequence polynomial representation. Also, a#k,p,i» a#k,P,2, and a#k,P,3 (where k=l, 2, 3, ..., 3g, and p = l, 2, 3 n_l) are integers (where a#k,P,i###k,P,2#a#k>p,3), and b#k,i, b#k,2, and b#k,3 are integers (where b#k,i#b#k,2#b#k,3). Furthermore, "c%d" indicates "a remainder after dividing c by d." 2. The encoding method according to claim 1, wherein n = 2 in Equation 1-k. 3. The encoding method according to claim 1, wherein: in the first parity check polynomial, an,p.3-0, and (a#i,i,i%3, a#i,i,2%3), (a#lj2>1%3, a#i>2i2%3), ..., (a#i,„-i>i%3, a#i>n-i)2%3) are either (1, 2) or (2, 1), b#i,3 = 0, and (b#i,i%3, b#i.2%3) is either (1, 2) or (2, 1); in the second parity check polynor&ial, a#2,P,3 = 0, and (a#2,i,i%3, a#2,i,2%3), (a#2.2.i%3, a#2,2,2%3), ..., (a#2,n-n%3, a#2,„.i,2%3) are either (1, 2) or (2, 1), b#2,3 = 0, and (b#2,i%3, b#2,2%3) is either (I, 2) or (2, 1); in the kk'th parity check polynomial, a#kk,P,3 = 0, and (a#kk,i,i%3, a#kk,i,2%3), (a#kk 2,i%3, a#kk,2,2%3), ..., (a#kk,n.i,i%3, aakjci-1,2%3) are either (1, 2) or (2, 1), &#kk,3=o\ and" (b)tkk,i%3, 6#kk,2%#J is eitnei- (it 2) or (2, I); and in the 3g'th parity check polynomial, a#3g,p,3 = 0, and (a#3g,i,i%3, a#3g,i,2%3), (a#ig>2.i%3, a#3g,2,2%3), ..., (a, 3g,n-i.i%3, a#3g>n-i,2%3) are either (1, 2) or (2, 1), b#3g,3 = 0, and (b#3g,i%3, b#3g,2%3) is either (l, 2) or (2, 1). 4. The encoding method according to claim 3, wherein n = 2 in Equation 1-k. 5. The encoding method according to claim 3, wherein: in orders of Xi(D) of the first through 3g'th parity check polynomials, all values other than multiples of 3 from among integers from 0 to 3g-l are present in 6g values (a#i,i,i%3g, a#i,i,2%3g), (a#2.i,i%3g, a#2,i,2%3g), ..., (a#3g,i,i%3g, a#3g,i,2%3g); and in orders of X2(D) of the first through 3g'th parity check polynomials, all values other than multiples of 3 from among integers from 0 to 3g-l are present in 6g values (a#i,2,i%3g, a#il2,2%3g), {a#2,2,i%3g, a#2,2,2%3g), ..., (a#3g,2,i%3g, a#3gi2,2%3g); and in orders of XP(D) of the first through 3 g * t h parity check polynomials, all values other than multiples of 3 from among integers from 0 to 3g-l are present in 6g values (a#i)Pii%3g, an,P,2%3g), (a#2,p,i%3g, a#2,P,2%3g), ..., (a#3g,P,i%3g, a#3g,P,2%3g); and in orders of Xn-i(D) of the first through 3g'th parity check polynomials, all values other than multiples of 3 from among integers from 0 to 3g-l are present in 6g values (a#ii„.i)i%3g, a#l,n-l,2%3g), (a*2,n-l.l%3g, a#2,n-l,2%3g), ..., (a#3g,n.i,i%3g, a#3S,n-i,2%3g); and in orders of P(D) of the first through 3g'th parity check polynomials, all values other than multiples of 3 from among integers from 0 to 3g-l are present in 6g values (b#iji%3g, b#J>2%3g), (b#2.i%3g, b#2>2%3g), ..., (b#3gil%3g, b#3g)2%3g). 6. The encoding method according to claim 5, wherein n = 2 in Equation 1-k. 7. The encoding method according to claim 1, wherein g = l. 8. An encoder that creates a Low-Density Parity-Check Convolutional Code (LDPC-CC) from a convolutional code, the encoder comprising a parity calculation section that finds a parity sequence by means of the encoding method according to claim 1. 9. A decoder that decodes a Low-Density Parity-Check Convolutional Code (LDPC-CC) using Belief Propagation (BP), the decoder comprising: a row processing computation section that performs row processing computation using a parity check matrix corresponding to a parity check polynomial used by the encoder according to claim 8; a column processing computation section that performs column processing computation using the parity check matrix; and a determination section that estimates a codeword using computation results of the row processing computation section and the column processing computation section. _ ... .-it.