DESCRIPTION
[Title of Invention]
TRANSMITTER, TRANSMISSION METHOD, RECEIVER, RECEPTION
METHOD, PROGRAM, AND INTEGRATED CIRCUIT
[Technical Field]
[0001]
The present invention relates to technology for reducing the Peak to
Average Power Ratio (PAPR) caused by Layer-1 (L1) signaling data that indicates
transmission parameters of a main Signal.
[Background Art]
[0002]
DVB-T (Digital Video Broadcasting-Terrestrial) is a transmission standard
for terrestrial digital television broadcasting in Europe. The digitalization of
television broadcasts has become widespread, not only in Europe, but in other
countries as well. To yield more efficient use of frequencies, DVB-T2
standardization was started in 2006 for second generation terrestrial digital
television broadcasting. Like the DVB-T, DVB-T2 adopts OFDM (Orthogonal
Frequency Division Multiplexing).
[0003]
Fig. 31 shows the transmission frame structure in DVB-T2. DVB-T2
utilizes a concept called the PLP (Physical Layer Pipe). One characteristic of
DVB-T2 is that transmission parameters, such as the modulation method, coding
ratio, and the like may be set independently for each PLP. The number of PLPs is at
least 1 and at most 255. The example in Fig. 31 shows the case of 10 PLPs.
[0004]
The following describes the transmission frame structure.
[0005]
Super Frame = N_T2 frames (N_T2 = 2-255)
Frame = Pi symbol + P2 symbols + data symbols
Pi symbol = 1 symbol
P2 symbols = N__P2 symbols (N_P2 is unique based on FFT size)
Data symbols = L_data symbols (L_data is variable, having an upper limit
and a lower limit)
A Pi symbol is transmitted with an FFT size of 1k and GI (GUARD
INTERVAL) = 1/2. The Pi symbol transmits seven bits of information, Si and S2,
with information on the FFT size and the like of subsequent P2 symbols and data
symbols. The earlier portion of P2 symbols include L1 signaling data, and the
remaining later portion includes main signal data. The data symbols include a
continuation of the main signal data.
[0006]
The L1 signaling data transmitted in P2 symbols is composed of L1-pre
signaling data, which mainly transmits information shared by all of the PLPs, and
L1-post signaling data, which mainly transmits information on each PLP. Note that
details on the L1 signaling data, L1-pre signaling data, and L1-post signaling data
transmitted in P2 symbols is listed in Non-Patent Literature 1.
[0007]
Fig. 32 shows the structure of a transmitter 1000 conforming to DVB-T2
(see Non-Patent Literature 1: DVB-T2 transmission standards). The transmitter 1000
is provided with a main signal coder 1011, an L1 signaling data coder 1012, a frame
builder 1013, and an OFDM signal generator 1014.
[0008]
For each PLP of a main signal that is to be transmitted, the main signal
coder 1011 performs error correction coding based on BCH coding and LDPC
coding, performs interleaving, performs mapping onto I/Q coordinates, and outputs
the mapping data for each PLP. Note that I represents the in-phase component,
whereas Q represents the quadrature component.
[0009]
The L1 signaling data coder 1012 performs error correction coding on the
L1-pre signaling data and the L1-post signaling data, performs interleaving,
performs mapping onto I/Q coordinates, and outputs the mapping data for the L1-pre signaling data and the L1-post signaling data.
[0010]
The frame builder 1013 generates and outputs the transmission frame
structure according to the DVB-T2 standard as shown in Fig. 31 using the mapping
data for each PLP output by the main Signal coder 1011 and the mapping data for the
L1-pre signaling data and the L1-post signaling data output by the L1 signaling data
coder 1012.
[0011]
To the transmission frame structure according to the DVB-T2 standard as
output by the frame builder 1013, the OFDM Signal generator 1014 adds a Pilot Signal, performs an IFFT (Inverse Fast Fourier Transform), inserts a GI, and inserts a
P1 symbol, outputting a transmission Signal according to DVB-T2.
[0012]
The following provides details on the L1 signaling data coder 1012. As
shown in Fig. 32, the L1 signaling data coder 1012 is provided with an L1 signaling
data generator 1021, an L1 error correction coder 1022, an L1-pre mapper 1023, an
L1-post bit interleaver 1025, and an L1-post mapper 1026. The L1 error correction
coder 1022 is provided with an L1-pre error correction coder 1031 and an L1-post
error correction coder 1032.
[0013]
In the L1 signaling data coder 1012, the L1 signaling data generator 1021
generates L1 signaling data from transmission parameters, i.e. transforms
transmission parameters into L1 signaling data (L1-pre signaling data and L1-post signaling data) and outputs the L1 signaling data. The L1-pre error correction coder
1031 performs error correction coding, based on BCH coding and LDPC coding, on
the L1-pre signaling data. The L1-pre mapper 1023 maps the error correction coded
L1-pre signaling data to I/Q coordinates, outputting mapping data for the L1-pre signaling data.
[0014]
On the other hand, the L1-post error correction coder 1032 performs error
correction coding, based on BCH coding and LDPC coding, on the Ll-post signaling data. The Ll-post bit interleaver 1025 interleaves the error correction
coded Ll-post signaling data in units of bits. The Ll-post mapper 1026 maps the
Ll-post signaling data, which has been error correction coded and interleaved in
units of bits, to I/Q coordinates, outputting mapping data for the Ll-post signaling
data.
[0015]
Fig. 33 shows the structure of a receiver 1100 conforming to DVB-T2 (see
Non-Patent Literature 2: DVB-T2 implementation guidelines). The receiver 1100 is
provided with an antenna 1111, a tuner 1112, an A/D converter 1113, an OFDM
demodulator 1114, a selected PLP/L1 signaling data extraction unit 1115, a main Signal decoder 1116, and an L1 signaling data decoder 1117.
[0016]
The antenna 1111 receives radio waves. The tuner 1112 selectively receives
an OFDM Signal of a deS1red channel and down-converts the Signal to a
predetermined band. The A/D converter 1113 converts the Signal output by the tuner
1112 from analog to digital. The OFDM demodulator 1114 performs OFDM
demodulation on the Signal output by the A/D converter 1113 and outputs mapping
data in I/Q coordinates.
[0017]
The selected PLP/L1 signaling data extraction unit 1115 extracts the L1-pre signaling data and the Ll-post signaling data from the OFDM demodulated Signal
(mapping data in I/Q coordinates), outputting the extracted information. Following a
selected PLP instruction, the selected PLP/L1 signaling data extraction unit 1115
also extracts the PLP (main Signal) selected by the user. Note that the selected
PLP/L1 signaling data extraction unit 1115 extracts the PLP (main Signal) selected
by the user after processing by the L1 signaling data decoder 1117, using the
transmission parameters output by the L1 signaling data decoder 1117.
[0018]
The L1 signaling data decoder 1117 demaps the extracted L1-pre signaling
data and L1-post signaling data from I/Q coordinates and deinterleaves these data
that were interleaved at the transmitting end. The L1 signaling data decoder 1117
then performs error correction decoding based on LDPC decoding and BCH
decoding, analyzes the decoded (reproduced) L1 signaling data, and outputs
transmission parameters.
[0019]
Based on the transmission parameters output by the L1 signaling data
decoder 1117, the main Signal decoder 1116 demaps the extracted PLP (main Signal)
from I/Q coordinates and deinterleaves the PLP that was interleaved at the
transmitting end. The main Signal decoder 1116 then performs error correction
decoding based on LDPC decoding and BCH decoding and outputs the decoded
(reproduced) main Signal.
[0020]
The following provides details on the L1 signaling data decoder 1117. As
shown in Fig. 33, the L1 signaling data decoder 1117 is provided with an L1-pre
demapper 1121, an L1-post demapper 1122, an L1-post bit deinterleaver 1123, an L1 error correction decoder 1124, and an L1 signaling data analyzer 1125. The L1 error
correction decoder 1124 is provided with an L1-pre error correction decoder 1131
and an L1-post error correction decoder 1132.
[0021]
In the L1 signaling data decoder 1117, the L1-pre demapper 1121 demaps
the extracted L1-pre signaling data from I/Q coordinates. The L1-pre error
correction decoder 1131 performs error correction decoding of the demapped L1-pre signaling data based on LDPC decoding and BCH decoding.
[0022]
On the other hand, the L1-post demapper 1122 demaps the extracted
Ll-post signaling data from I/Q coordinates. The Ll-post bit deinterleaver 1123
deinterleaves the demapped Ll-post signaling data that was interleaved at the
transmitting end in units of bits. The Ll-post error correction decoder 1132 performs
error correction decoding of the bit-deinterleaved Ll-post signaling data based on
LDPC decoding and BCH decoding.
[0023]
The L1 signaling data analyzer 1125 analyzes the decoded (reproduced)
L1-pre signaling data and the Ll-post signaling data and outputs the transmission
parameters. Note that among the Ll-post signaling data, the L1 signaling data
analyzer 1125 follows a selected PLP instruction to extract and analyze the
transmission parameters for the PLP selected by the user.
[Citation List]
Non-Patent Literature
[0024]
Non-Patent Literature 1: EN 302 755 VI.1.1: Frame structure channel
coding and modulation for a second generation digital terrestrial television
broadcasting system (DVB-T2)
Non-Patent Literature 2: DVB BlueBook A133: Implementation guidelines
for a second generation digital terrestrial television broadcasting system (DVB-T2)
[Summary of Invention]
[Technical Problem]
[0025]
Preparations for the start of service under the DVB-T2 standard have
advanced the furthest in the UK. The main target is HDTV (High Definition
Tele-vision) service for stationary reception, and the number of PLPs is expected to
be one.
[0026]
As described above, the maximum number of PLPs that can be transmitted
with DVB-T2 is 255. Multiple PLPs are appropriate for a mobile service that
transmits content with a low bit rate as the main Signal. Currently, in the context of
DVB, DVB-NGH (Next Generation Handheld) is being examined. DVB-NGH is a
second generation mobile standard for terrestrial digital television broadcasting. If
DVB-NGH uses the PLP structure of DVB-T2, the number of PLPs is expected to
increase, Since DVB-NGH is a mobile standard. The inventors examined the case of
when the number of PLPs is large, an issue that up until now has not been
considered highly important within the DVB-T2 standard.
[0027]
Fig. 34 is an example of transmission parameters when the number of PLPs
is 255. The largest difference from when the number of PLPs is one, as in the main
use case in the DVB-T2 standard, is that the proportion of the P2 symbols occupied
by L1 signaling data increases, whereas the proportion occupied by the PLP (main Signal) decreases.
[0028]
In other words, when the number of PLPs is one, the number of bits in the
L1 signaling data is small, and the P2 symbols are almost entirely occupied by the
main Signal. As a result, the properties of the P2 symbols are nearly identical to the
properties of the data symbols.
[0029]
By contrast, when the number of PLPs is 255, the number of bits in the L1 signaling data increases, and the P2 symbols are almost entirely occupied by the L1
signaling data. This may result in different properties for the P2 symbols and the
data symbols. The inventors focused on this point, analyzing the properties of the P2
symbols and the data symbols when the number of PLPs is 255, as shown in Fig. 34.
[0030]
Figs. 35A and 35B are the results of analysis of the power of P2 symbols
and data symbols in a DVB-T2 transmission Signal (a Signal in the time domain after
an IFFT) output by the transmitter 1000 of Fig. 32. In both Figs. 35A and 35B, the
horizontal axis represents the symbol number within a frame. Symbol 0 is a P2
symbol, and symbols 1 and higher are data symbols.
[0031]
The vertical axis in Fig. 35A represents the average power of each symbol.
As Fig. 35A shows, the P2 symbol has nearly 10% higher power than the data
symbols. The vertical axis in Fig. 35B represents the peak power of the entire
sample included in each symbol. As Fig. 35B shows, the P2 symbol has dozens of
times greater power than the data symbols.
[0032]
Next, the inventors focused analysis on the peak power of the P2 symbols.
Fig. 36 shows the power in each sample within the P2 symbol. As is clear, power is
concentrated in the sample in the beginning of the P2 symbol. To investigate the
reason, the inventors analyzed the L1-pre signaling data and the L1-post signaling
data for the transmission parameters in Fig. 34. Fig. 37 shows the results of analysis.
[0033]
As Fig. 37 shows, the number of bits that are 0's is overwhelmingly larger
than the number of bit that are l's in the L1-pre signaling data and the L1-post signaling data. In part, the parameters N_TI and I_JUMP related to time interleaving
are eight bits, but Since the value of these parameters is small, the only bits near the
least Significant bit are 1 's, and the number of bits that are 0's is large. Since the
N_TI and I_JUMP are independent parameters for each PLP, these parameters are
one of the main reasons for the increase in the proportion of bits that are 0's. As
N_TI and I_JUMP are parameters related to time interleaving, it is quite possible for
these parameters to have small values.
[0034]
Fig. 38 shows the candidate transmission parameters for the DVB-T2
service in the UK (number of PLPs: 1) and the results of analysis of the L1-pre signaling data and L1-post signaling data. In this case as well, the number of bits
that are 0's in the L1-pre signaling data and the L1-post signaling data is larger than
the number of bits that are 1 's. Since the number of PLPs is one, however, the
proportion of the L1 signaling data in the P2 symbols is small. Furthermore, the
L1-post bit interleaver 1025 interleaves the L1-post signaling data, which mainly
transmits information on each PLP, in units of bits. These two phenomena prevent a
bias in the mapping data for the L1-pre signaling data and the L1-post signaling
data.
[0035]
On the other hand, if the number of PLPs is large, the proportion of the P2
symbols occupied by the L1 signaling data is large. Therefore, even when the
L1-post bit interleaver 1025 performs interleaving in units of bits, a large bias
remained in the mapping data for the L1-pre signaling data and the L1-post signaling data. This is the reason for the concentration of power in a specific sample
within the P2 symbols.
[0036]
As described above, the inventors discovered the problem that when the
number of PLPs is large, the power becomes concentrated in a specific sample
within the P2 symbols. For such a transmission Signal, the influence of clipping by
the receiver on the P2 symbols becomes prominent. This results in reduced receiving
performance of the L1-pre signaling data and the L1-post signaling data and may
make reception impossible. If the L1-pre signaling data and the L1-post signaling
data are not receivable, the transmission parameters of the PLP (main Signal) cannot
be acquired. This leads to the major problem of an inability to decode the main Signal.
[0037]
In order to prevent this problem, the influence of clipping by the receiver
needs to be avoided. It is therefore necessary to greatly increase the dynamic range
of the receiver, i.e. to greatly increase the number of bits that can be Signal processed.
Such a modification leads to the problems of increased calculation load and
increased cost of the receiver.
[0038]
The present invention has been conceived in light of the above problems,
and it is one object thereof to provide a transmitter, a transmission method, and a
program that can suppress the bias in mapping data of the L1 signaling data and can
avoid the concentration of power within a specific sample of symbols (for example,
P2 symbols). Furthermore, it is another object of the present invention to provide a
receiver, a reception method, a program, and an integrated circuit that can avoid the
influence of clipping without requiring an increase in dynamic range, while
suppressing an increased calculation load and increased cost.
[Solution to Problem]
[0039]
In order to solve the above problems, a transmitter according to an aspect of
the present invention comprises: an L1 (Layer-1) signaling data generator
configured to generate, from transmission parameters of a main Signal, L1 signaling
data storing the transmission parameters; an energy dispersion and error correction
coding unit configured to perform energy dispersion on at least a portion of the L1 signaling data output by the L1 signaling data generator and to perform error
correction coding on the L1 signaling data; and a mapper configured to perform
mapping on the energy-dispersed, error correction coded L1 signaling data output by
the energy dispersion and error correction coding unit.
[Advantageous Effects of Invention]
[0040]
With the above structure, a bias in the mapping data of the L1 signaling data
is randomized by energy dispersion of at least a portion of the L1 signaling data,
thus avoiding concentration of power in a specific sample within symbols (for
example, P2 symbols).
[Brief Description of Drawings]
[0041]
Fig. 1 shows the structure of a transmitter 100 in Embodiment 1.
Fig. 2 shows the structure of the energy dispersion unit 121 of Fig. 1.
Fig. 3 shows the structure of a receiver 150 in Embodiment 1.
Fig. 4 shows the structure of a transmitter 200 in Embodiment 2.
Fig. 5 shows the structure of a receiver 250 in Embodiment 2.
Fig. 6 shows the structure of a transmitter 300 in Embodiment 3.
Fig. 7 shows L1-pre signaling data and L1-post signaling data in
Embodiment 3.
Fig. 8 shows the structure of a receiver 350 in Embodiment 3.
Fig. 9 shows the structure of a transmitter 400 in Embodiment 4.
Fig. 10 shows the structure of a receiver 450 in Embodiment 4.
Figs. 11A, 11B, and 11C show the improvement when adopting
Embodiments 1 and 2.
Fig. 12 shows the structure of a transmitter 100A in Embodiment 5.
Fig. 13 shows the structure of the energy dispersion unit 121A of Fig. 12.
Fig. 14 shows the structure of a receiver 150A in Embodiment 5.
Fig. 15 shows the structure of a transmitter 200A in Embodiment 6.
Fig. 16 shows the structure of a receiver 250A in Embodiment 6.
Fig. 17 shows the structure of a transmitter 300A in Embodiment 7.
Fig. 18 shows the structure of a receiver 350A in Embodiment 7.
Fig. 19 shows the structure of a transmitter 400A in Embodiment 8.
Fig. 20 shows the structure of a receiver 450A in Embodiment 8.
Fig. 21 shows the overall structure of a digital broadcasting system in
Embodiment 9.
Fig. 22 shows an example of the structure of a receiver.
Fig. 23 shows the structure of multiplexed data.
Fig. 24 schematically shows how each stream is multiplexed in the
multiplexed data.
Fig. 25 shows in detail how a video stream is stored in a sequence of PES
packets.
Fig. 26 shows the structure of a TS packet and a source packet in
multiplexed data.
Fig. 27 shows the data structure of a PMT.
Fig. 28 shows the internal structure of multiplexed data information.
Fig. 29 shows the internal structure of stream attribute information.
Fig. 30 is a structural diagram of a video display / audio output device.
Fig. 31 shows the transmission frame structure in the DVB-T2 standard.
Fig. 32 shows the structure of a conventional transmitter for the DVB-T2
standard.
Fig. 33 shows the structure of a conventional receiver for the DVB-T2
standard.
Fig. 34 shows an example of transmission parameters when the number of
PLPS is 255.
Figs. 35A and 35B show the results of analysis of the power of P2 symbols
and data symbols in a DVB-T2 transmission Signal (a Signal in the time domain after
an IFFT).
Fig. 36 shows the power for each sample in P2 symbols.
Fig. 37 shows the results of analysis of the L1-pre signaling data and the
L1-post signaling data for the transmission parameters in Fig. 34.
Fig. 38 shows the candidate transmission parameters for DVB-T2 service in
the UK (number of PLPs: 1) and the results of analysis of the L1-pre signaling data
and L1-post signaling data.
[Description of Embodiments]
[0042]
A first transmitter according to an aspect of the present invention comprises:
an L1 (Layer-1) signaling data generator configured to generate, from transmission
parameters of a main Signal, L1 signaling data storing the transmission parameters;
an energy dispersion and error correction coding unit configured to perform energy
dispersion on at least a portion of the L1 signaling data output by the L1 signaling
data generator and to perform error correction coding on the L1 signaling data; and a
mapper configured to perform mapping on the energy-dispersed, error correction
coded L1 signaling data output by the energy dispersion and error correction coding
unit.
[0043]
A first transmission method according to an aspect of the present invention
comprises the steps of: (a) generating, from transmission parameters of a main
Signal, L1 (Layer-1) signaling data storing the transmission parameters; (b)
performing energy dispersion on at least a portion of the L1 signaling data generated
in step (a) and performing error correction coding on the L1 signaling data; and (c)
performing mapping on the L1 signaling data that is energy-dispersed and error
correction coded in step (b).
[0044]
A first transmitting Side program according to an aspect of the present
invention causes a transmitter to perform the steps of: (a) generating, from
transmission parameters of a main Signal, L1 (Layer-1) signaling data storing the
transmission parameters; (b) performing energy dispersion on at least a portion of
the L1 signaling data generated in step (a) and performing error correction coding on
the L1 signaling data; and (c) performing mapping on the L1 signaling data that is
energy-dispersed and error correction coded in step (b).
[0045]
The first transmitter, the first transmission method, and the first transmitting
Side program each perform energy dispersion on at least a portion of the L1
signaling data. This allows for randomization of a bias in mapping data of the L1
signaling data and avoidance of the concentration of power within a specific sample
of symbols (for example, P2 symbols).
[0046]
A second transmitter according to an aspect of the present invention is the
first transmitter, wherein the main Signal is transmitted in PLPs (Physical Layer
Pipes), transmission parameters of each PLP being set independently, and the energy
dispersion and error correction coding unit only performs the energy dispersion
when a total number of the PLPs exceeds a predetermined number.
[0047]
The second transmitter does not perform energy dispersion at the
transmitting end for a broadcast service in which the number of PLPs does not
exceed a predetermined number. This has the advantage of allowing for reception by
a conventional receiver.
[0048]
A third transmitter according to an aspect of the present invention is the
second transmitter, wherein the L1 signaling data is divided into L1-pre signaling
data and L1-post signaling data, the L1-post signaling data storing the total number
of the PLPs, the L1 signaling data generator stores, in the Ll-pre signaling data,
energy dispersion information indicating whether energy dispersion has been
performed, and the energy dispersion and error correction coding unit performs the
energy dispersion on the L1-post signaling data.
[0049]
Without using special information outside of the L1 signaling data, the third
transmitter can indicate, to the receiving end, whether or not energy dispersion has
been performed.
[0050]
A fourth transmitter according to an aspect of the present invention is the
first transmitter, wherein the L1 signaling data is divided into L1-pre signaling data
and L1-post signaling data, and the energy dispersion and error correction coding
unit performs the energy dispersion using a PRBS (Pseudo Random Binary
Sequence) and initializes the PRBS at a start of the L1-pre signaling data.
[0051]
A fifth transmitter according to an aspect of the present invention is the
fourth transmitter, wherein the energy dispersion and error correction coding unit
also initializes the PRBS at a start of the Ll-post signaling data.
[0052]
A Sixth transmitter according to an aspect of the present invention is the
fifth transmitter, wherein the Ll-post signaling data is formed by a plurality of error
correction code blocks, and the energy dispersion and error correction coding unit
also initializes the PRBS at a start of each error correction code block in the Ll-post
signaling data.
[0053]
A seventh transmitter according to an aspect of the present invention is the
first transmitter, wherein the energy dispersion and error correction coding unit
includes: an energy dispersion unit configured to perform the energy dispersion on
the L1 signaling data output by the L1 signaling data generator; and an error
correction coding unit configured to perform the error correction coding on the
energy-dispersed L1 signaling data output by the energy dispersion unit.
[0054]
An eighth transmitter according to an aspect of the present invention is the
first transmitter, wherein the energy dispersion and error correction coding unit
includes: an error correction coding unit configured to perform the error correction
coding on the L1 signaling data output by the L1 signaling data generator; and an
energy dispersion unit configured to perform the energy dispersion on the error
correction coded L1 signaling data output by the error correction coding unit.
[0055]
A ninth transmitter according to an aspect of the present invention
comprises: an L1 (Layer-1) signaling data generator configured to generate, from
transmission parameters of a main Signal, L1 signaling data storing the transmission
parameters; an error correction coding unit configured to perform error correction
coding on the L1 signaling data output by the L1 signaling data generator; and a
mapper configured to perform mapping on the error correction coded L1 signaling
data output by the error correction coding unit, wherein the L1 signaling data
generator inverts a bit pattern of a portion of the L1 signaling data when generating
the L1 signaling data.
[0056]
A second transmission method according to an aspect of the present
invention comprises the steps of: (a) generating, from transmission parameters of a
main Signal, L1 (Layer-1) signaling data storing the transmission parameters; (b)
performing error correction coding on the L1 signaling data generated in step (a);
and (c) performing mapping on the L1 signaling data that is error correction coded
in the step (b), wherein a bit pattern of a portion of the L1 signaling data is inverted
when the L1 signaling data is generated in step (a).
[0057]
The ninth transmitter and the second transmission method invert the bit
pattern of a portion of the L1 signaling data. This allows for randomization of a bias
in mapping data of the L1 signaling data and avoidance of the concentration of
power within a specific sample of symbols (for example, P2 symbols).
[0058]
A tenth transmitter according to an aspect of the present invention is the
ninth transmitter, wherein the main Signal is transmitted in PLPs (Physical Layer
Pipes), transmission parameters of each PLP being set independently, and the L1
signaling data generator inverts the bit pattern only when a total number of the PLPs
exceeds a predetermined number.
[0059]
The tenth transmitter does not invert the bit pattern of a portion of the L1
signaling data at the transmitting end for a broadcast service in which the number of
PLPs does not exceed a predetermined number. This has the advantage of allowing
for reception by a conventional receiver.
[0060]
An eleventh transmitter according to an aspect of the present invention is
the ninth transmitter, wherein the main Signal is transmitted in PLPs (Physical Layer
Pipes), transmission parameters of each PLP being set independently, the L1
signaling data is divided into L1-pre signaling data and L1-post signaling data, and
the portion of the L1 signaling data is a portion of the L1-post signaling data
pertaining to a portion of the PLPs and excluding a PLP_ID.
[0061]
A twelfth transmitter according to an aspect of the present invention is the
eleventh transmitter, wherein the portion of the PLPs is composed of all PLPs
having an odd ID number or all PLPs having an even ID number.
[0062]
A thirteenth transmitter according to an aspect of the present invention
comprises: an L1 (Layer-1) signaling data generator configured to generate, from
transmission parameters of a main Signal, L1 signaling data storing the transmission
parameters; an error correction coding unit configured to perform error correction
coding on the L1 signaling data output by the L1 signaling data generator; and a
mapper configured to perform mapping on the error correction coded L1 signaling
data output by the error correction coding unit, wherein the L1 signaling data
generator switches on use of an extension field and assigns each bit of the extension
field a value of 1 or of 0 so as to decrease a difference between a total number of 0
bits and a total number of 1 bits of the L1 signaling data.
[0063]
A third transmission method according to an aspect of the present invention
comprises the steps of: (a) generating, from transmission parameters of a main
Signal, L1 (Layer-1) signaling data storing the transmission parameters; (b)
performing error correction coding on the L1 signaling data generated in step (a);
and (c) performing mapping on the L1 signaling data that is error correction coded
in the step (b), wherein in step (a), use of an extension field is switched on, and each
bit of the extension field is assigned a value of 1 or of 0 so as to decrease a
difference between a total number of 0 bits and a total number of 1 bits of the L1
signaling data.
[0064]
The thirteenth transmitter and the third transmission method assign each bit
of the extension field a value of 1 or of 0 so as to decrease the difference between
the total number of 0 bits and the total number of 1 bits of the extension field of the
L1 signaling data. This allows for randomization of a bias in mapping data of the L1
signaling data and avoidance of the concentration of power within a specific sample
of symbols (for example, P2 symbols). Furthermore, this achieves the advantage of
allowing for reception by a conventional receiver that ignores the extension field.
[0065]
A fourteenth transmitter according to an aspect of the present invention is
the thirteenth transmitter, wherein the main Signal is transmitted in PLPs (Physical
Layer Pipes), transmission parameters of each PLP being set independently, and the
L1 signaling data generator switches on use of the extension field only when a total
number of the PLPs exceeds a predetermined number.
[0066]
The fourteenth transmitter switches off use of the extension field in the case
of a transmission service in which the number of PLPs does not exceed the
predetermined number. The fourteenth transmitter can therefore avoid an increase in
transmission quantity.
[0067]
A fifteenth transmitter according to an aspect of the present invention is the
thirteenth transmitter, wherein the L1 signaling data is divided into L1-pre signaling
data and L1-post signaling data, and the extension field is an L1-post extension field
in the L1-post signaling data.
[0068]
The fifteenth transmitter allows for direct use of the structure of the L1-post
signaling data in the DVB-T2 format.
[0069]
A first receiver according to an aspect of the present invention is for
receiving L1 (Layer-1) signaling data storing transmission parameters of a main
Signal, energy dispersion having been performed on at least a portion of the L1
signaling data, and error correction coding having been performed on the entire L1
signaling data, the receiver comprising: an error correction decoding and reverse
energy dispersion unit configured to reproduce the L1 signaling data by performing
error correction decoding on a received Signal and performing reverse energy
dispersion on at least a portion of the received Signal; and an L1 signaling data
analyzer configured to analyze the reproduced L1 signaling data output by the error
correction decoding and reverse energy dispersion unit and to output transmission
parameters.
[0070]
A first reception method according to an aspect of the present invention is
for receiving L1 (Layer-1) signaling data storing transmission parameters of a main
Signal, energy dispersion having been performed on at least a portion of the L1
signaling data, and error correction coding having been performed on the entire L1
signaling data, the reception method comprising the steps of: (a) reproducing the L1
signaling data by performing error correction decoding on a received Signal and
performing reverse energy dispersion on at least a portion of the received Signal; and
(b) analyzing the L1 signaling data reproduced in step (a) and outputting
transmission parameters.
[0071]
A first receiving Side program according to an aspect of the present
invention is used in a receiver for receiving L1 (Layer-1) signaling data storing
transmission parameters of a main Signal, energy dispersion having been performed
on at least a portion of the L1 signaling data, and error correction coding having
been performed on the entire L1 signaling data, the program causing the receiver to
perform the steps of: (a) reproducing the L1 signaling data by performing error
correction decoding on a received Signal and performing reverse energy dispersion
on at least a portion of the received Signal; and (b) analyzing the L1 signaling data
reproduced in step (a) and outputting transmission parameters.
[0072]
A first receiving Side integrated circuit according to an aspect of the present
invention is for receiving input of L1 (Layer-1) signaling data storing transmission
parameters of a main Signal, energy dispersion having been performed on at least a
portion of the L1 signaling data, and error correction coding having been performed
on the entire L1 signaling data, the integrated circuit comprising: an error correction
decoding and reverse energy dispersion circuit configured to reproduce the L1
signaling data by performing error correction decoding on a received Signal and
performing reverse energy dispersion on at least a portion of the received Signal; and
an L1 signaling data analysis circuit configured to analyze the reproduced L1
signaling data output by the error correction decoding and reverse energy dispersion
circuit and to output transmission parameters.
[0073]
The first receiver, the first reception method, the first receiving Side
program, and the first receiving Side integrated circuit do not require an increase in
dynamic range in order to avoid the influence of clipping, while suppressing an
increased calculation load and increased cost.
[0074]
A second receiver according to an aspect of the present invention is the first
receiver, wherein the main Signal is transmitted in PLPs (Physical Layer Pipes),
transmission parameters of each PLP being set independently, the energy dispersion
has only been performed when a total number of the PLPs exceeds a predetermined
number, and the error correction decoding and reverse energy dispersion unit only
performs the reverse energy dispersion when the total number of the PLPs exceeds
the predetermined number.
[0075]
A third receiver according to an aspect of the present invention is the second
receiver, wherein the L1 signaling data is divided into L1-pre signaling data and
L1-post signaling data, the L1-post signaling data storing the total number of the
PLPs, energy dispersion information indicating whether energy dispersion has been
performed is stored in the L1-pre signaling data, the energy dispersion has only been
performed on the L1-post signaling data, and the error correction decoding and
reverse energy dispersion unit performs the reverse energy dispersion on the L1-post
signaling data only when the energy dispersion information indicates that the energy
dispersion has been performed.
[0076]
Without using special information outside of the L1 signaling data, the third
receiver can receive a notification, from the transmitting end, regarding whether or
not energy dispersion has been performed.
[0077]
A fourth receiver according to an aspect of the present invention is the first
receiver, wherein the L1 signaling data is divided into L1-pre signaling data and
L1-post signaling data, and the error correction decoding and reverse energy
dispersion unit performs the reverse energy dispersion using a PRBS (Pseudo
Random Binary Sequence) and initializes the PRBS at a start of the L1-pre signaling
data.
[0078]
A fifth receiver according to an aspect of the present invention is the fourth
receiver, wherein the error correction decoding and reverse energy dispersion unit
also initializes the PRBS at a start of the L1-post signaling data.
[0079]
A Sixth receiver according to an aspect of the present invention is the fifth
receiver, wherein the L1-post signaling data is formed by a plurality of error
correction code blocks, and the error correction decoding and reverse energy
dispersion unit also initializes the PRBS at a start of each error correction code block
in the L1-post signaling data.
[0080]
A seventh receiver according to an aspect of the present invention is the first
receiver, wherein the error correction decoding and reverse energy dispersion unit
includes: an error correction decoding unit configured to perform the error
correction decoding on the energy-dispersed, error correction coded L1 signaling
data; and a reverse energy dispersion unit configured to perform the reverse energy
dispersion on the error correction decoded L1 signaling data output by the error
correction decoding unit.
[0081]
An eighth receiver according to an aspect of the present invention is the first
receiver, wherein the error correction decoding and reverse energy dispersion unit
includes: a reverse energy dispersion unit configured to perform the reverse energy
dispersion on the energy-dispersed, error correction coded L1 signaling data; and an
error correction decoding unit configured to perform the error correction decoding
on the reverse energy-dispersed L1 signaling data output by the reverse energy
dispersion unit.
[0082]
A ninth receiver according to an aspect of the present invention is for
receiving error correction coded L1 (Layer-1) signaling data storing transmission
parameters of a main Signal, a bit pattern of a portion of the L1 signaling data having
been inverted upon generation of the L1 signaling data, the receiver comprising: an
error correction decoding unit configured to perform error correction decoding on
the error correction coded L1 signaling data; and an L1 signaling data analyzer
configured to analyze the error correction decoded L1 signaling data output by the
error correction decoding unit and to output transmission parameters, wherein the L1
signaling data analyzer analyzes the L1 signaling data using the inversionn of the bit
pattern of the portion of the L1 signaling data.
[0083]
A second reception method according to an aspect of the present invention
is for receiving L1 (Layer-1) signaling data storing transmission parameters of a
main Signal, energy dispersion having been performed on at least a portion of the L1
signaling data, and error correction coding having been performed on the entire L1
signaling data, the reception method comprising the steps of: (a) reproducing the L1
signaling data by performing error correction decoding on a received Signal and
performing reverse energy dispersion on at least a portion of the received Signal; and
(b) analyzing the L1 signaling data reproduced in step (a) and outputting
transmission parameters.
[0084]
The ninth receiver and the second reception method do not require an
increase in dynamic range in order to avoid the influence of clipping, while
suppressing an increased calculation load and increased cost.
[0085]
A tenth receiver according to an aspect of the present invention is the ninth
receiver, wherein the main Signal is transmitted in PLPs (Physical Layer Pipes),
transmission parameters of each PLP being set independently, the bit pattern of the
portion of the L1 signaling data has been inverted only when a total number of the
PLPs exceeds a predetermined number, and the L1 signaling data analyzer analyzes
the L1 signaling data by determining, based on the total number of the PLPs and on
the predetermined number, whether the bit pattern of the portion of the L1 signaling
data for the transmission parameters has been inverted.
[0086]
An eleventh receiver according to an aspect of the present invention is the
ninth receiver, wherein the main Signal is transmitted in PLPs (Physical Layer Pipes),
transmission parameters of each PLP being set independently, the L1 signaling data
is divided into L1-pre signaling data and L1-post signaling data, and a portion of the
L1 signaling data is a portion of the L1-post signaling data pertaining to a portion of
the PLPs and excluding a PLP_ID.
[0087]
A twelfth receiver according to an aspect of the present invention is the
eleventh receiver, wherein the portion of the PLPs is composed of all PLPs having
an odd ID number or all PLPs having an even ID number.
[0088]
A thirteenth receiver according to an aspect of the present invention is for
receiving error correction coded L1 (Layer-1) signaling data storing transmission
parameters of a main Signal, upon generation of the L1 signaling data, use of an
extension field having been switched on, and each bit of the extension field having
been assigned a value of 1 or of 0 so as to decrease a difference between a total
number of 0 bits and a total number of 1 bits of the L1 signaling data, the receiver
comprising: an error correction decoding unit configured to perform error correction
decoding on the error correction coded L1 signaling data; and an L1 signaling data
analyzer configured to analyze the error correction decoded L1 signaling data output
by the error correction decoding unit and to output transmission parameters.
[0089]
A third reception method according to an aspect of the present invention is
for receiving error correction coded L1 (Layer-1) signaling data storing transmission
parameters of a main Signal, upon generation of the L1 signaling data, use of an
extension field having been switched on, and each bit of the extension field having
been assigned a value of 1 or of 0 so as to decrease a difference between a total
number of 0 bits and a total number of 1 bits of the L1 signaling data, the reception
method comprising the steps of: (a) performing error correction decoding on the
error correction coded L1 signaling data; and (b) analyzing the L1 signaling data that
is error correction decoded in step (a) and outputting transmission parameters.
[0090]
The thirteenth receiver and the third reception method do not require an
increase in dynamic range in order to avoid the influence of clipping, while
suppressing an increased calculation load and increased cost.
[0091]
A fourteenth receiver according to an aspect of the present invention is the
thirteenth receiver, wherein the main Signal is transmitted in PLPs (Physical Layer
Pipes), transmission parameters of each PLP being set independently, and use of the
extension field has been switched on only when a total number of the PLPs exceeds
a predetermined number.
[0092]
The fourteenth receiver switches off use of the extension field in the case of
a transmission service in which the number of PLPs does not exceed the
predetermined number. The fourteenth receiver can therefore avoid an increase in
transmission quantity.
[0093]
A fifteenth receiver according to an aspect of the present invention is the
thirteenth receiver, wherein the L1 signaling data is divided into L1-pre signaling
data and L1-post signaling data, and the extension field is an L1-post extension field
in the L1-post signaling data.
[0094]
The fifteenth receiver allows for direct use of the structure of the L1-post
signaling data in the DVB-T2 format.
[0095]
The following describes embodiments of the present invention in detail with
reference to the drawings.
[0096]
Embodiment 1
Fig. 1 shows the structure of a transmitter 100 in Embodiment 1 of the
present invention. Structural elements that are the same as a conventional transmitter
bear the same reference Signs, and a description thereof is omitted.
[0097]
As compared to the conventional transmitter 1000 of Fig. 32, the transmitter
100 of Fig. 1 further includes an energy dispersion unit 121 in an L1 signaling data
coder 111.
[0098]
In the transmitter 100 of Fig. 1, the energy dispersion unit 121 performs
energy dispersion in order on the L1-pre signaling data and the L1-post signaling
data generated by the L1 signaling data generator 1021. The L1-pre error correction
coder 1031 performs error correction coding, based on BCH coding and LDPC
coding, on the energy-dispersed L1-pre signaling data. The L1-post error correction
coder 1032 performs error correction coding, based on BCH coding and LDPC
coding, on the energy-dispersed L1-post signaling data.
[0099]
Fig. 2 shows the structure of the energy dispersion unit 121 of Fig. 1. The
energy dispersion unit 121 uses a 15th order PRBS (Pseudo Random Binary
Sequence) as a dispersion sequence, as shown in the following expression.
[0100]
1 + X14 + X15
As shown in Fig. 2, in the energy dispersion unit 121, the L1-pre signaling
data and the L1-post signaling data are input into a combination unit 131 from the
L1 signaling data generator 1021. The combination unit 131 outputs bits of the
L1-pre signaling data in order from the first to the last bit and then outputs bits of
the L1-post signaling data in order from the first to the last bit. An EXOR
(ExcluS1ve OR) circuit 133 performs an EXOR calculation on the 14th bit and 15th
bit output from a 15-bit shift register 132. An EXOR circuit 134 performs an EXOR
calculation on the output of the EXOR circuit 133 and each of (i) the bits of the
L1-pre signaling data and (ii) the L1-post signaling data. A distribution unit 135
outputs the energy-dispersed L1-pre signaling data, output by the EXOR circuit 134,
to the L1-pre error correction coder 1031 and outputs the energy-dispersed L1-post
signaling data to the L1-post error correction coder 1032. Note that at the timing of
the first bit of the L1-pre signaling data, an initial value of "100101010000000" is
assigned to the 15-bit shift register 132. From the second bit to the last bit of the
L1-pre signaling data, and from the first bit to the last bit of the subsequent L1-post
signaling data, the 15-bit shift register 132 operates sequentially, without assignment
of the initial value.
[0101]
Other operations are the same as the conventional transmitter 1000 of Fig.
32.
[0102]
Fig. 3 shows the structure of a receiver 150 in Embodiment 1 of the present
invention. Structural elements that are the same as a conventional receiver bear the
same reference Signs, and a description thereof is omitted.
[0103]
As compared to the conventional receiver 1100 of Fig. 33, the receiver 150
of Fig. 3 further includes a reverse energy dispersion unit 171 in an L1 signaling
data decoder 161.
[0104]
In the receiver 150 of Fig. 3, the reverse energy dispersion unit 171
performs reverse energy dispersion in order on the L1 -pre signaling data decoded by
the L1-pre error correction decoder 1131 and the L1-post signaling data decoded by
the L1-post error correction decoder 1132 to return these data to their state before
the energy dispersion performed at the transmitting end by the energy dispersion unit
121. The structure of the reverse energy dispersion unit 171 is the same as the
structure of the energy dispersion unit 121 in Fig. 2. The source of input for the
combination unit 131 is the L1-pre error correction decoder 1131 and the L1-post
error correction decoder 1132, and the destination of output from the distribution
unit 135 is the L1 signaling data analyzer 1125. The L1 signaling data analyzer 1125
analyzes the L1-pre signaling data and the L1-post signaling data after reverse
energy dispersion and outputs the transmission parameters.
[0105]
S1nce the reverse energy dispersion unit 171 is a structural element that
reverses the energy dispersion performed at the transmitting end by the energy
dispersion unit 121, the reverse energy dispersion unit 171 uses the 15th order PRBS
in the following expression as a dispersion sequence, just as the energy dispersion
unit 121 does.
[0106]
1+X14 + X15
The initial value assigned to the shift register 132 in the reverse energy
dispersion unit 171 and the timing of assignment of the initial value need to match
the initial value assigned to the shift register 132 in the energy dispersion unit 121
and the timing of assignment of the initial value. Therefore, in the reverse energy
dispersion unit 171, an initial value of "100101010000000" is assigned to the 15-bit
shift register 132 at the timing of the first bit of the L1-pre signaling data. From the
second bit to the last bit of the L1-pre signaling data, and from the first bit to the last
bit of the subsequent L1-post signaling data, the 15-bit shift register 132 operates
sequentially, without assignment of the initial value.
[0107]
Other operations are the same as the conventional receiver 1100 of Fig. 33.
[0108]
Note that in the receiver 150 of Fig. 3, structural elements other than the
antenna 1111 and the tuner 1112 may be provided as an integrated circuit 151.
[0109]
With the above structure, even when the number of PLPs is large, a large
bias in the mapping data of the L1-pre signaling data and the L1-post signaling data
is randomized, thus avoiding concentration of power in specific samples within the
P2 symbols. As a result, the influence of clipping in the receiver 150 can be avoided
without requiring an increase in dynamic range, while suppressing an increased
calculation load and increased cost of the receiver 150.
[0110]
Embodiment 2
Fig. 4 shows the structure of a transmitter 200 in Embodiment 2 of the
present invention. Structural elements that are the same as a conventional transmitter
and as the transmitter of Embodiment 1 bear the same reference Signs, and a
description thereof is omitted.
[0111]
As compared to the conventional transmitter 1000 of Fig. 32, the transmitter
200 of Fig. 4 further includes an energy dispersion unit 121 in an L1 signaling data
coder 211. The location in which the energy dispersion unit 121 is added differs,
however, between Embodiment 1 and Embodiment 2.
[0112]
In the transmitter 200 of Fig. 4, the energy dispersion unit 121 performs
energy dispersion in order on the error correction coded L1-pre signaling data output
by the L1-pre error correction coder 1031 and the error correction coded L1-post
signaling data output by the L1-post error correction coder 1032. The structure of
the energy dispersion unit 121 is as shown in Fig. 2. The source of input and
destination of output of information differs between the energy dispersion unit 121
of Embodiment 1 and the energy dispersion unit 121 of Embodiment 2.
[0113]
The L1-pre mapper 1023 maps the error correction coded, energy-dispersed
L1-pre signaling data to I/Q coordinates, outputting mapping data for the L1-pre signaling data.
[0114]
The L1-post bit interleaver 1025 interleaves the error correction coded,
energy-dispersed L1-post signaling data in units of bits,
[0115]
Other operations are the same as the conventional transmitter 1000 of Fig.
32.
[0116]
Fig. 5 shows the structure of a receiver 250 in Embodiment 2 of the present
invention. Structural elements that are the same as a conventional receiver and the
receiver of Embodiment 1 bear the same reference Signs, and a description thereof is
omitted.
[0117]
As compared to the conventional receiver 1100 of Fig. 33, the receiver 250
of Fig. 5 further includes a reverse energy dispersion unit 171 in an L1 signaling
data decoder 261. The location in which the reverse energy dispersion unit 171 is
added differs, however, between Embodiment 1 and Embodiment 2.
[0118]
In the receiver 250 of Fig. 5, the reverse energy dispersion unit 171
performs reverse energy dispersion in order on the demapped L1-pre signaling data
output by the L1-pre demapper 1121 and on the demapped, bit-deinterleaved
L1-post signaling data output by the L1-post bit deinterleaver 1123, thus reversing
the energy dispersion performed at the transmitting end by the energy dispersion unit
121. The structure of the reverse energy dispersion unit 171 is the same as the
energy dispersion unit 121 shown in Fig. 2. The source of input and destination of
output of information, however, differs between the reverse energy dispersion unit
171 of Embodiment 1 and the reverse energy dispersion unit 171 of Embodiment 2.
[0119]
The L1-pre error correction decoder 1131 performs error correction
decoding of the L1-pre signaling data, on which reverse energy dispersion has been
performed, based on LDPC decoding and BCH decoding. The L1-post error
correction decoder 1132 performs error correction decoding of the L1-post signaling
data, on which reverse energy dispersion has been performed, based on LDPC
decoding and BCH decoding.
[0120]
Other operations are the same as the conventional receiver 1100 of Fig. 33.
[0121]
Note that in the receiver 250 of Fig. 5, structural elements other than the
antenna 1111 and the tuner 1112 may be provided as an integrated circuit 251.
[0122]
With the above structure, even when the number of PLPs is large, a large
bias in the mapping data of the L1-pre signaling data and the L1-post signaling data
is randomized, thus avoiding concentration of power in specific samples within the
P2 symbols. As a result, the influence of clipping in the receiver 250 can be avoided
without requiring an increase in dynamic range, while suppressing an increased
calculation load and increased cost of the receiver 250.
[0123]
In Embodiment 1, energy dispersion is only performed on information bits
of error correction coding based on BCH coding and LDPC coding. By contrast, in
Embodiment 2, energy dispersion is performed on information bits and on parity bits
of error correction coding based on BCH coding and LDPC coding. Therefore, as
compared to Embodiment 1, Embodiment 2 offers the possibility of further
suppressing bias in the mapping data of the L1 signaling data.
[0124]
Embodiment 3
Fig. 6 shows the structure of a transmitter 300 in Embodiment 3 of the
present invention. Structural elements that are the same as a conventional transmitter
bear the same reference Signs, and a description thereof is omitted.
[0125]
As compared to the conventional transmitter 1000 of Fig. 32, the transmitter
300 of Fig. 6 differs in the configuration of an L1 signaling data generator 321 in an
L1 signaling data coder 311.
[0126]
In the transmitter 300 of Fig. 6, the L1 signaling data generator 321
generates L1 signaling data from transmission parameters, i.e. transforms
transmission parameters into L1 signaling data (L1-pre signaling data and L1-post
signaling data) and outputs the L1 signaling data. At this point, the L1 signaling data
generator 321 inverts the bit pattern in the L1-post signaling data of the L1-post
signaling data portions (excluding the PLPI_ID) pertaining to PLPs with an
odd-numbered PLP_ID. Note that the L1 signaling data generator 321 does not
invert the bit pattern of other portions of the L1-post signaling data.
[0127]
The L1-pre error correction coder 1031 performs error correction coding,
based on BCH coding and LDPC coding, on the L1-pre signaling data output by the
L1 signaling data generator 321. On the other hand, the L1-post error correction
coder 1032 performs error correction coding, based on BCH coding and LDPC
coding, on the L1-post signaling data (the bit pattern of which has been inverted)
output by the L1 signaling data generator 321.
[0128]
Fig. 7 shows the Ll-pre signaling data and the Ll-post signaling data when
adopting the present embodiment for the transmission parameters when the number
of PLPs is 255, as shown in Fig. 34. The bit pattern inversion excludes the PLP_ID
and is performed on the bits surrounded by the dotted-line in Fig. 7.
[0129]
Note that instead of inverting the bit pattern in the Ll-post signaling data of
the Ll-post signaling data portions (excluding the PLP_ID) pertaining to PLPs with
an odd-numbered PLP_ID, the L1 signaling data generator 321 may invert the bit
pattern in the Ll-post signaling data of the Ll-post signaling data portions
(excluding the PLP_ID) pertaining to PLPs with an even-numbered PLP_ID.
[0130]
Other operations are the same as the conventional transmitter 1000 of Fig.
32.
[0131]
Fig. 8 shows the structure of a receiver 350 in Embodiment 3 of the present
invention. Structural elements that are the same as a conventional receiver bear the
same reference Signs, and a description thereof is omitted.
[0132]
As compared to the conventional receiver 1100 of Fig. 33, the receiver 350
of Fig. 8 differs in the configuration of an L1 signaling data analyzer 371 in an L1
signaling data decoder 361.
[0133]
In the receiver 350 of Fig. 8, the L1 signaling data analyzer 371 analyzes the
decoded L1-pre signaling data and L1-post signaling data, outputting the
transmission parameters. Among the L1-post signaling data, the L1 signaling data
analyzer 371 follows a selected PLP instruction to extract and analyze the
transmission parameters for the PLP selected by the user. At this point, the L1
signaling data analyzer 371 determines, based on the PLP_ID, whether the bit
pattern of the L1-post signaling data portion pertaining to the PLP selected by the
user has been inverted. If not, the L1 signaling data analyzer 371 analyses the
information as is. If, however, the bit pattern has been inverted, the L1 signaling data
analyzer 371 first inverts the bit pattern, then performs analysis and outputs the
transmission parameters.
[0134]
Note that in Embodiment 3, Since the bit pattern of PLPs whose PLP_ID is
an odd number is inverted at the transmitting end, it is determined that the bit pattern
has been inverted when the PLP_ID of the PLP selected by the user is odd, and that
the bit pattern has not been inverted when the PLP_ID is even.
[0135]
Note that when the target of inversion at the transmitting end is the bit
pattern of PLPs whose PLP_ID is even, it is determined that the bit pattern has been
inverted when the PLP_ID of the PLP selected by the user is even, and that the bit
pattern has not been inverted when the PLP_ID is odd.
[0136]
Other operations are the same as the conventional receiver 1100 of Fig. 33.
[0137]
Note that in the receiver 350 of Fig. 8, structural elements other than the
antenna 1111 and the tuner 1112 may be provided as an integrated circuit 351.
[0138]
With the above structure, even when the number of PLPs is large, a large
bias in the mapping data of the L1-pre signaling data and the L1-post signaling data
is prevented, thus avoiding concentration of power in specific samples within the P2
symbols. As a result, the influence of clipping in the receiver 350 can be avoided
without requiring an increase in dynamic range, while suppressing an increased
calculation load and increased cost of the receiver.
[0139]
Embodiment 4
Fig. 9 shows the structure of a transmitter 400 in Embodiment 4 of the
present invention. Structural elements that are the same as a conventional transmitter
bear the same reference Signs, and a description thereof is omitted.
[0140]
As compared to the conventional transmitter 1000 of Fig. 32, the transmitter
400 of Fig. 9 differs in the configuration of an L1 signaling data generator 421 in an
L1 signaling data coder 411.
[0141]
In the transmitter 400 of Fig. 9, the L1 signaling data generator 421
generates L1 signaling data from transmission parameters, i.e. transforms
transmission parameters into L1 signaling data (L1-pre signaling data and L1-post
signaling data) and outputs the L1 signaling data. At this point, the L1 signaling data
generator 421 switches on use of the L1-post extension field (the portion surrounded
by the dotted line in Fig. 31) in the Ll-post signaling data shown in Fig. 31 and fills
a predetermined number of bits of the Ll-post extension field in the Ll-post
signaling data with l's. One possible reference for deciding on the number of
predetermined bits is the number of PLPs. For example, the number of bits per PLP
to be filled with l's may be determined. The product of this number and the number
of PLPs then becomes the number of predetermined bits. The number of bits to be
filled with l's per PLP is determined, for example, to be a predetermined proportion
(such as 80%) of the bits in the Ll-post signaling data for one PLP. Note that the
method of determining the predetermined number of bits with reference to the
number of PLPs is not limited to the above method.
[0142]
The L1 signaling data generator 421 may count the number of 0's and 1 's in
the L1-pre signaling data and the Ll-post signaling data, deciding on the number of
predetermined bits that would make the number of 0's and l's even. The L1
signaling data generator 421 then fills the predetermined number of bits of the
Ll-post extension field of the Ll-post signaling data with the value (0 or 1) that
occurs less. In this case, if the number of l's in the L1-pre signaling data or the
Ll-post signaling data is larger, then the predetermined number of bits are filled
with 0's. Conversely, if the number of 0's in the L1-pre signaling data or the Ll-post
signaling data is larger, then the predetermined number of bits are filled with 1 's.
Note that instead of deciding on the predetermined number of bits so that the
number of 0's and l's becomes even, a predetermined number of bits may be
decided on so that the difference between the number of 0's and of 1 's falls within a
predetermined value (for example, a value determined based on the results of
Simulation, or measurement in an actual device, of the difference between the
number of 0's and 1 's such that bias in the mapping data does not cause negative
influence at the receiving end).
[0143]
The L1-pre error correction coder 1031 performs error correction coding,
based on BCH coding and LDPC coding, on the L1-pre signaling data output by the
L1 signaling data generator 421. On the other hand, the L1-post error correction
coder 1032 performs error correction coding, based on BCH coding and LDPC
coding, on the L1-post signaling data (with the predetermined number of bits of the
L1-post extension field having been filled) output by the L1 signaling data generator
421.
[0144]
Other operations are the same as the conventional transmitter 1000 of Fig.
32.
[0145]
In this context, the L1-post extension field is a field provided for future
extension of the L1 signaling data. Since the L1-post extension field may be ignored
at the receiving end, a receiver 450 having the same structure as the conventional
receiver 1100 of Fig. 33 can decode a DVB-T2 transmission Signal.
[0146]
Note that as shown in Fig. 10, in the receiver 450, structural elements other
than the antenna 1111 and the tuner 1112 may be provided as an integrated circuit
451.
[0147]
With the above structure, even when the number of PLPs is large, a large
bias in the mapping data of the L1-pre signaling data and the L1-post signaling data
is prevented, thus avoiding concentration of power in specific samples within the P2
symbols. As a result, the influence of clipping in the receiver 450 can be avoided
without requiring an increase in dynamic range, while suppressing an increased
calculation load and increased cost of the receiver 450. In particular, Embodiment 4
has the advantage that a conventional receiver is useable without modification.
[0148]
Considerations Regarding Embodiments 1 and 2
The inventors examined the improvement when adopting Embodiments 1
and 2 to the transmission parameters when the number of PLPs shown in Fig. 34
was 255 and to the transmission parameters when the number of PLPs was smaller
than 255. Figs. 11A through 11C show the results. The analysis was performed on a
DVB-T2 transmission Signal (a Signal in the time domain after an IFFT).
[0149]
Fig. 11A is a table summarizing the results of analysis. For the number of
PLPs between 1 and 255, the proportion of the L1 signaling data in the P2 symbols
(NumLl/NumActiveCarrier) is also shown. In Fig. 11 A, "NumL1PreCells" is the
number of cells of L1-pre signaling data per frame. "NumL1PostCells" is the
number of cells of L1-post signaling data per frame. "NumActiveCarrier" is the
number of active carriers per symbol. "NumP2Symbols" is the number of P2
symbols per frame. "PAPR w/o Scramble" is the PAPR of the conventional
transmitter 1000. "PAPR w Scramble before Coding" is the PAPR when adopting
Embodiment 1, and "PAPR w Scramble after Coding" is the PAPR when adopting
Embodiment 2.
[0150]
The horizontal axis of Fig. 11B shows the number of PLPs, and the
horizontal axis of Fig. 11C shows the proportion of the L1 signaling data in the P2
symbols. The vertical axis of Figs. 11B and 11C shows the PAPR, defined as
follows.
PAPR = peak power of the entire sample included in the P2 symbols /
average power of all symbols excluding P2 symbols
[0151]
As Figs. 11B and 11C show, the PAPR (PAPR w/o Scramble) of the
conventional transmitter 1000 increases by 13.7 dB when the number of PLPs
increases from one to 255. On the other hand, the PAPR (PAPR w Scramble before
Coding) when adopting Embodiment 1 remains constant. The PAPR (PAPR w
Scramble after Coding) when adopting Embodiment 2 also remains constant.
[0152]
Based on the above, the energy dispersion of Embodiments 1 and 2 clearly
provides a great improvement in the PAPR. Furthermore, it is clear that when the
number of PLPs is one, or when the proportion of L1 signaling data in the P2
symbols is small and the PAPR of the P2 symbols is equivalent to the data symbols,
the energy dispersion of Embodiments 1 and 2 does not exert a negative influence.
[0153]
Figs. 11B and 11C show that when the number of PLPs is 15 or 31, the
PAPR is nearly the same as when the number of PLPs is one, even in the
conventional example that does not adopt Embodiment 1 or 2.
[0154]
Based on this fact, Embodiments 1 through 4 may, for example, be modified
so that when the number of PLPs is 31 or less, operations are performed as in the
conventional example, whereas when the number of PLPs exceeds 31, operations
are performed as described in Embodiments 1 through 4. Note that the number of
PLPs for switching between operations as in the conventional example and
operations as described in Embodiments 1 through 4 is not limited to "31", as a
different number may be used. For example, the number of PLPs for switching
operations may be determined in accordance with the deS1red PAPR.
[0155]
This modification is described below in detail in Embodiments 5 through 8.
[0156]
Embodiment 5
Fig. 12 shows the structure of a transmitter 100A in Embodiment 5 of the
present invention. Structural elements that are the same as a conventional transmitter
and as the transmitter of Embodiment 1 bear the same reference Signs, and a
description thereof is omitted.
[0157]
As compared to the transmitter 100 of Fig. 1 in Embodiment 1, the
transmitter 100A of Fig. 12 differs in the configuration of an L1 signaling data
generator 1021A and an energy dispersion unit 121A in an L1 signaling data
generator 111 A. Furthermore, an energy dispersion control unit 126 is added.
[0158]
The L1 signaling data generator 1021A generates L1 signaling data from
transmission parameters, i.e. transforms transmission parameters into L1 signaling
data (L1-pre signaling data and L1-post signaling data) and outputs the L1 signaling
data. At this point, if the number of PLPs exceeds a predetermined number, the L1
signaling data generator 1021A stores, in the Ll-pre signaling data, information
indicating that energy dispersion has been performed at the transmitting end. If the
number of PLPs does not exceed a predetermined number, the L1 signaling data
generator 1021A stores, in the Ll-pre signaling data, information indicating that
energy dispersion has not been performed at the transmitting end. The field in which
this information is stored is, for example, a RESERVED field in the Ll-pre signaling
data.
[0159]
The energy dispersion control unit 126 identifies the number of PLPs from
the transmission parameters. When the number of PLPs exceeds the predetermined
number, the energy dispersion control unit 126 turns the energy dispersion
operations of the energy dispersion unit 121A ON, whereas when the number of
PLPs does not exceed the predetermined number, the energy dispersion control unit
126 turns the energy dispersion operations of the energy dispersion unit 121A OFF.
[0160]
When the energy dispersion operations have been turned ON by the energy
dispersion control unit 126, the energy dispersion unit 121A performs energy
dispersion in order on the L1-post signaling data output by the L1 signaling data
generator 1021A and outputs the energy-dispersed L1-post signaling data to the
L1-post error correction coder 1032. On the other hand, when the energy dispersion
operations have been turned OFF by the energy dispersion control unit 126, the
energy dispersion unit 121A outputs L1-post signaling data on which energy
dispersion has not been performed (identical to the L1-post signaling data output by
the L1 signaling data generator 1021A) to the Ll-post error correction coder 1032.
[0161]
Fig. 13 shows the structure of the energy dispersion unit 121A of Fig. 12.
The energy dispersion unit 121A uses a 15th order PRBS as a dispersion sequence, as
shown in the following expression.
[0162]
1+X14 + X15
A selector 136 in the energy dispersion unit 121A is controlled by the
energy dispersion control unit 126 so that, when the energy dispersion operations are
OFF (when the number of PLPs does not exceed the predetermined number), the
selector 136 selects the Ll-post signaling data output by the L1 signaling data
generator 1021A and outputs the Ll-post signaling data to the Ll-post error
correction coder 1032. On the other hand, the selector 136 is controlled by the
energy dispersion control unit 126 so that, when the energy dispersion operations are
ON (when the number of PLPs exceeds the predetermined number), the selector 136
selects the energy-dispersed Ll-post signaling data output by the EXOR circuit 134
and outputs the Ll-post signaling data to the Ll-post error correction coder 1032.
Note that at the timing of the first bit of the Ll-post signaling data, an initial value of
"100101010000000" is assigned to the 15-bit shift register 132. From the second bit
to the last bit of the Ll-post signaling data, the 15-bit shift register 132 operates
sequentially, without assignment of the initial value.
[0163]
In this context, it is necessary at the receiving end to determine whether or
not energy dispersion was performed at the transmitting end. Therefore, the number
of PLPs used as the reference for whether to perform energy dispersion is stored in
the L1-post signaling data. If energy dispersion is Simply performed on the L1-post
signaling data, it will be impossible at the receiving end to determine whether or not
to perform reverse energy dispersion. In Embodiment 5, therefore, an indication of
whether energy dispersion is performed is stored in the L1-pre signaling data. The
L1-pre signaling data, which stores this indication of whether energy dispersion is
performed, is not energy dispersed; rather, energy dispersion is performed only on
the L1-post signaling data. The same is true in Embodiment 6 below as well.
[0164]
The L1-pre error correction coder 1031 performs error correction coding,
based on BCH coding and LDPC coding, on the L1-pre signaling data output by the
L1 signaling data generator 1021 A. The L1-post error correction coder 1032
performs error correction coding, based on BCH coding and LDPC coding, on the
energy-dispersed L1-post signaling data, or on the L1-post signaling data on which
energy dispersion has not been performed, output by the energy dispersion unit
121A.
[0165]
Other operations are the same as the conventional transmitter 1000 of Fig.
32.
[0166]
Fig. 14 shows the structure of a receiver 150A in Embodiment 5 of the
present invention. Structural elements that are the same as a conventional receiver
and the receiver of Embodiment 1 bear the same reference Signs, and a description
thereof is omitted.
[0167]
As compared to the receiver 150 of Fig. 3 in Embodiment 1, the receiver
150A of Fig. 14 differs in the configuration of a reverse energy dispersion unit 171A
and an L1 signaling data analyzer 1125A in an L1 signaling data decoder 161A.
Furthermore, a reverse energy dispersion control unit 176 is added.
[0168]
The L1 signaling data analyzer 1125A analyzes whether the decoded L1 -pre
signaling data output by the L1-pre error correction decoder 1131 has been energy
dispersed at the transmitting end and outputs the results of analysis to the reverse
energy dispersion control unit 176.
[0169]
Based on the results of analysis from the L1 signaling data analyzer 1125A,
the reverse energy dispersion control unit 176 turns reverse energy dispersion
operations of the reverse energy dispersion unit 171A ON when energy dispersion
has been performed at the transmitting end and turns reverse energy dispersion
operations of the reverse energy dispersion unit 171A OFF when energy dispersion
has not been performed at the transmitting end.
[0170]
When reverse energy dispersion operations have been turned ON by the
reverse energy dispersion control unit 176, the reverse energy dispersion unit 171A
performs reverse energy dispersion in order on the decoded L1-post signaling data
output by the L1-post error correction decoder 1132, outputting the reverse
energy-dispersed L1-post signaling data to the L1 signaling data analyzer 1125A. On
the other hand, when reverse energy dispersion operations have been turned OFF by
the reverse energy dispersion control unit 176, the reverse energy dispersion unit
171A outputs the L1-post signaling data on which reverse energy dispersion has not
been performed (identical to the decoded L1-post signaling data output by the
L1-post error correction decoder 1132) to the L1 signaling data analyzer 1125A. The
structure of the reverse energy dispersion unit 171A is the same as that of the energy
dispersion unit 121A shown in Fig. 13. The source of input is the L1-post error
correction decoder 1132, and the destination of output is the L1 signaling data
analyzer 1125A. A selector 136 in the reverse energy dispersion unit 171A is
controlled by the reverse energy dispersion control unit 176 so that, when the
reverse energy dispersion operations are OFF (when the number of PLPs does not
exceed the predetermined number), the selector 136 selects the L1-post signaling
data output by the L1-post error correction decoder 1132 and outputs the L1-post
signaling data to the L1 signaling data analyzer 1125A. On the other hand, the
selector 136 is controlled by the reverse energy dispersion control unit 176 so that,
when the energy dispersion operations are ON (when the number of PLPs exceeds
the predetermined number), the selector 136 selects the energy dispersed L1-post
signaling data output by the EXOR circuit 134 and outputs the L1-post signaling
data to the L1 signaling data analyzer 1125A. The L1 signaling data analyzer 1125A
analyzes the L1-pre signaling data and the L1-post signaling data and outputs the
transmission parameters.
[0171]
S1nce the reverse energy dispersion unit 171A is a structural element that
reverses the energy dispersion performed at the transmitting end by the energy
dispersion unit 121 A, the reverse energy dispersion unit 171A uses the 15th order
PRBS in the following expression as a dispersion sequence, just as the energy
dispersion unit 121Adoes.
[0172]
1+X14 + X15
The initial value assigned to the shift register 132 in the reverse energy
dispersion unit 171A and the timing of assignment of the initial value need to match
the initial value assigned to the shift register 132 in the energy dispersion unit 121A
and the timing of assignment of the initial value. Therefore, in the reverse energy
dispersion unit 171A, an initial value of "100101010000000" is assigned to the
15-bit shift register 132 at the timing of the first bit of the L1-post signaling data.
From the second bit to the last bit of the L1-post signaling data, the 15-bit shift
register 132 operates sequentially, without assignment of the initial value.
[0173]
Other operations are the same as the conventional receiver 1100 of Fig. 33.
[0174]
Note that in the receiver 150A of Fig. 14, structural elements other than the
antenna 1111 and the tuner 1112 may be provided as an integrated circuit 151 A.
[0175]
With the above structure, even when the number of PLPs is large, a large
bias in the mapping data of the L1-pre signaling data and the L1-post signaling data
is randomized, thus avoiding concentration of power in specific samples within the
P2 symbols. As a result, the influence of clipping in the receiver 150A can be
avoided without requiring an increase in dynamic range, while suppressing an
increased calculation load and increased cost of the receiver 150A. Furthermore, the
above structure offers the advantage that a conventional receiver can receive a
broadcast service in which the number of PLPs does not exceed the predetermined
number, Since in this case energy dispersion is not performed.
[0176]
Embodiment 6
Fig. 15 shows the structure of a transmitter 200A in Embodiment 6 of the
present invention. Structural elements that are the same as a conventional transmitter
and as the transmitter of Embodiments 1, 2, and 5 bear the same reference Signs, and
a description thereof is omitted.
[0177]
As compared to the transmitter 200 of Fig. 4 in Embodiment 2, the
transmitter 200A of Fig. 15 differs in the configuration of an L1 signaling data
generator 1021A and an energy dispersion unit 121A in an L1 signaling data
generator 111A. Furthermore, an energy dispersion control unit 126 is added. The
location in which the energy dispersion unit 121A is added differs, however,
between Embodiment 5 and Embodiment 6.
[0178]
In the transmitter 200A of Fig. 15, when the energy dispersion operations
have been turned ON by the energy dispersion control unit 126, the energy
dispersion unit 121A performs energy dispersion in order on the error correction
coded L1-post signaling data output by the L1-post error correction coder 1032 and
outputs the energy-dispersed L1-post signaling data to the L1-post bit interleaver
1025. On the other hand, when the energy dispersion operations have been turned
OFF by the energy dispersion control unit 126, the energy dispersion unit 121A
outputs error correction coded L1-post signaling data on which energy dispersion
has not been performed (identical to the error correction coded L1-post signaling
data output by the L1-post error correction coder 1032) to the L1-post bit interleaver
1025. The structure of the energy dispersion unit 121A is as shown in Fig. 13. The
source of input and destination of output of information differs between the energy
dispersion unit 121A of Embodiment 5 and the energy dispersion unit 121A of
Embodiment 6.
[0179]
The L1-pre mapper 1023 maps the error correction coded L1-pre signaling
data, output by the L1-pre error correction coder 1031, to I/Q coordinates, outputting
mapping data for the L1-pre signaling data. On the other hand, the L1-post bit
interleaver 1025 interleaves, in units of bits, the error correction coded,
energy-dispersed L1-post signaling data, or the error correction coded L1-post
signaling data on which energy dispersion has not been performed, output by the
energy dispersion unit 121A.
[0180]
Other operations are the same as the conventional transmitter 1000 of Fig.
32.
[0181]
Fig. 16 shows the structure of a receiver 250A in Embodiment 6 of the
present invention. Structural elements that are the same as a conventional receiver
and the receiver of Embodiments 1, 2, and 5 bear the same reference Signs, and a
description thereof is omitted.
[0182]
As compared to the receiver 250 of Fig. 5 in Embodiment 2, the receiver
250A of Fig. 16 differs in the configuration of a reverse energy dispersion unit 171A
and an L1 signaling data analyzer 1125A in an L1 signaling data decoder 261 A.
Furthermore, a reverse energy dispersion control unit 176 is added. The location in
which the reverse energy dispersion unit 171A is added differs, however, between
Embodiment 5 and Embodiment 6.
[0183]
In the receiver 250A of Fig. 16, when reverse energy dispersion operations
have been turned ON by the reverse energy dispersion control unit 176, the reverse
energy dispersion unit 171A performs reverse energy dispersion in order on the
L1-post signaling data output by the L1-post bit deinterleaver 1123, thus reversing
the energy dispersion performed at the transmitting end by the energy dispersion unit
121A. The reverse energy dispersion unit 171A then outputs the Ll-post signaling
data on which reverse energy dispersion has been performed to the Ll-post error
correction decoder 1132. On the other hand, when reverse energy dispersion
operations have been turned OFF by the reverse energy dispersion control unit 176,
the reverse energy dispersion unit 171A outputs the Ll-post signaling data on which
reverse energy dispersion has not been performed (identical to the Ll-post signaling
data output by the Ll-post bit deinterleaver 1123) to the Ll-post error correction
decoder 1132. The structure of the reverse energy dispersion unit 171A is the same
as the energy dispersion unit 121A shown in Fig. 13. The source of input and
destination of output of information, however, differs between the reverse energy
dispersion unit 171A of Embodiment 5 and the reverse energy dispersion unit 171A
of Embodiment 6.
[0184]
The L1-pre error correction decoder 1131 performs error correction
decoding of the demapped L1-pre signaling data, output by the L1-pre demapper
1121, based on LDPC decoding and BCH decoding. The L1-post error correction
decoder 1132 performs error correction decoding, based on LDPC decoding and
BCH decoding, on the L1-post signaling data on which reverse energy dispersion
has been performed, or the L1-post signaling data on which reverse energy
dispersion has not been performed, output by the reverse energy dispersion unit
171A.
[0185]
Other operations are the same as the conventional receiver 1100 of Fig. 33.
[0186]
Note that in the receiver 250A of Fig. 16, structural elements other than the
antenna 1111 and the tuner 1112 may be provided as an integrated circuit 251 A.
[0187]
With the above structure, even when the number of PLPs is large, a large
bias in the mapping data of the L1-pre signaling data and the L1-post signaling data
is randomized, thus avoiding concentration of power in specific samples within the
P2 symbols. As a result, the influence of clipping in the receiver 250A can be
avoided without requiring an increase in dynamic range, while suppressing an
increased calculation load and increased cost of the receiver 250A. Furthermore, the
above structure offers the advantage that a conventional receiver is useable without
modification for a broadcast service in which the number of PLPs does not exceed
the predetermined number, Since in this case energy dispersion is not performed.
[0188]
In Embodiment 5, energy dispersion is only performed on information bits
of error correction coding based on BCH coding and LDPC coding. By contrast, in
Embodiment 6, energy dispersion is performed on information bits and on parity bits
of error correction coding based on BCH coding and LDPC coding. Therefore, as
compared to Embodiment 5, Embodiment 6 offers the possibility of further
suppressing bias in the mapping data of the L1 signaling data.
[0189]
Embodiment 7
Fig. 17 shows the structure of a transmitter 300A in Embodiment 7 of the
present invention. Structural elements that are the same as a conventional transmitter
bear the same reference Signs, and a description thereof is omitted.
[0190]
As compared to the transmitter 300 of Fig. 6 in Embodiment 3, the
transmitter 300A of Fig. 17 differs in the configuration of an L1 signaling data
generator 321A in an L1 signaling data coder 311 A.
[0191]
In the transmitter 300A of Fig. 17, the L1 signaling data generator 321A
generates L1 signaling data from transmission parameters, i.e. transforms
transmission parameters into L1 signaling data (L1-pre signaling data and L1-post
signaling data) and outputs the L1 signaling data. At this point, the L1 signaling data
generator 321A identifies the number of PLPs from the transmission parameters.
When the identified number of PLPs does not exceed a predetermined number, the
L1 signaling data generator 321A does not invert the bit pattern in the Ll-post
signaling data of the Ll-post signaling data portions pertaining to PLPs with an
odd-numbered PLP_ID. On the other hand, when the identified number of PLPs
exceeds a predetermined number, the L1 signaling data generator 321A inverts the
bit pattern in the Ll-post signaling data of the Ll-post signaling data portions
(excluding the PLP_ID) pertaining to PLPs with an odd-numbered PLP_ID. Note
that the L1 signaling data generator 321A does not invert the bit pattern of other
portions of the L1-post signaling data.
[0192]
The L1-pre error correction coder 1031 performs error correction coding,
based on BCH coding and LDPC coding, on the L1-pre signaling data output by the
L1 signaling data generator 321 A. On the other hand, the L1-post error correction
coder 1032 performs error correction coding, based on BCH coding and LDPC
coding, on the L1-post signaling data (the bit pattern of which either has or has not
been inverted) output by the L1 signaling data generator 321A.
[0193]
Note that instead of inverting the bit pattern in the L1-post signaling data of
the L1-post signaling data portions (excluding the PLP_ID) pertaining to PLPs with
an odd-numbered PLP_ID, the L1 signaling data generator 321A may invert the bit
pattern in the L1-post signaling data of the L1-post signaling data portions
(excluding the PLP_ID) pertaining to PLPs with an even-numbered PLP_ID.
[0194]
Other operations are the same as the conventional transmitter 1000 of Fig.
32.
[0195]
Fig. 18 shows the structure of a receiver 350A in Embodiment 7 of the
present invention. Structural elements that are the same as a conventional receiver
bear the same reference Signs, and a description thereof is omitted.
[0196]
As compared to the receiver 350 of Fig. 8 in Embodiment 3, the receiver
350A of Fig. 18 differs in the configuration of an L1 signaling data analyzer 371A in
an L1 signaling data coder 361 A.
[0197]
In the receiver 350A of Fig. 18, the L1 signaling data analyzer 371A
analyzes the decoded L1-pre signaling data and L1-post signaling data, outputting
the transmission parameters. Among the L1-post signaling data, the L1 signaling
data analyzer 371A follows a selected PLP instruction to extract and analyze the
transmission parameters for the PLP selected by the user. At this point, the L1
signaling data analyzer 371A determines, based on the number of PLPs and the
PLP_ID, whether the bit pattern has been inverted. If not, the L1 signaling data
analyzer 371A analyses the information as is. If, however, the bit pattern has been
inverted, the L1 signaling data analyzer 371A first inverts the bit pattern, then
performs analysis and outputs the transmission parameters.
[0198]
Note that in Embodiment 7, Since the bit pattern of PLPs whose PLP_ID is
an odd number is inverted at the transmitting end, it is determined that the bit pattern
has been inverted when the PLP_ID of the PLP selected by the user is odd and the
number of PLPs exceeds the predetermined number, and that the bit pattern has not
been inverted in any other case.
[0199]
Note that when the target of inversion at the transmitting end is the bit
pattern of PLPs whose PLP ID is even, it is determined that the bit pattern has been
inverted when the PLP_ID of the PLP selected by the user is even and the number of
PLPs exceeds the predetermined number, and that the bit pattern has not been
inverted in any other case.
[0200]
Other operations are the same as the conventional receiver 1100 of Fig. 33.
[0201]
With the above structure, even when the number of PLPs is large, a large
bias in the mapping data of the L1-pre signaling data and the L1-post signaling data
is randomized, thus avoiding concentration of power in specific samples within the
P2 symbols. As a result, the influence of clipping in the receiver 350A can be
avoided without requiring an increase in dynamic range, while suppressing an
increased calculation load and increased cost of the receiver 350A. Furthermore, the
above structure offers the advantage that a conventional receiver is useable without
modification for a broadcast service in which the number of PLPs does not exceed
the predetermined number, Since in this case the bit pattern is not inverted.
[0202]
Embodiment 8
Fig. 19 shows the structure of a transmitter 400A in Embodiment 8 of the
present invention. Structural elements that are the same as a conventional transmitter
bear the same reference Signs, and a description thereof is omitted.
[0203]
As compared to the transmitter 400 of Fig. 9 in Embodiment 3, the
transmitter 400A of Fig. 19 differs in the configuration of an L1 signaling data
generator 421A in an L1 signaling data coder 411 A.
[0204]
In the transmitter 400A of Fig. 19, the L1 signaling data generator 421A
generates L1 signaling data from transmission parameters, i.e. transforms
transmission parameters into L1 signaling data (L1-pre signaling data and L1-post
signaling data) and outputs the L1 signaling data. At this point, the L1 signaling data
generator 421A determines the number of PLPs from the transmission parameters.
When the number of PLPs does not exceed a predetermined number, the L1
signaling data generator 421A switches off use of the L1-post extension field (the
portion surrounded by the dotted line in Fig. 31) in the L1-post signaling data shown
in Fig. 31. On the other hand, when the number of PLPs exceeds a predetermined
number, the L1 signaling data generator 421A switches on use of the Ll-post
extension field (the portion surrounded by the dotted line in Fig. 31) in the Ll-post
signaling data shown in Fig. 31 and fills a predetermined number of bits of the
Ll-post extension field in the Ll-post signaling data with l's. The predetermined
number of bits may be decided on by referring to the number of PLPs, or by
counting the number of bits that are 0's and the number of bits that are 1 's in the
L1-pre signaling data and the L1-post signaling data, as described in Embodiment 4.
With the latter approach, the predetermined number of bits may in some cases be
filled with 0's.
[0205]
The L1-pre error correction coder 1031 performs error correction coding,
based on BCH coding and LDPC coding, on the L1-pre signaling data output by the
L1 signaling data generator 421 A. On the other hand, the L1-post error correction
coder 1032 performs error correction coding, based on BCH coding and LDPC
coding, on the L1-post signaling data (with the predetermined number of bits of the
L1-post extension field either having been filled or not having been filled) output by
the L1 signaling data generator 421 A.
[0206]
Other operations are the same as the conventional transmitter 1000 of Fig.
32.
[0207]
As described in Embodiment 4, the L1-post extension field is a field
provided for future extension of the L1 signaling data. Since the L1-post extension
field may be ignored at the receiving end, a receiver 450A, shown in Fig. 20, that
has the same structure as the conventional receiver 1100 of Fig. 33 can decode the
DVB-T2 transmission Signal.
[0208]
Note that as shown in Fig. 20, in the receiver 450A, structural elements
other than the antenna 1111 and the tuner 1112 may be provided as an integrated
circuit 451 A.
[0209]
With the above structure, even when the number of PLPs is large, a large
bias in the mapping data of the L1-pre signaling data and the L1-post signaling data
is prevented, thus avoiding concentration of power in specific samples within the P2
symbols. As a result, the influence of clipping in the receiver 450A can be avoided
without requiring an increase in dynamic range, while suppressing an increased
calculation load and increased cost of the receiver. Furthermore, the receiver
switches off use of the L1-post extension field of the L1-post signaling data when
the number of PLPs does not exceed a predetermined number, thereby preventing a
decrease in transmission capacity of the main Signal. In particular, Embodiment 8
has the advantage that a conventional receiver is useable without modification.
[0210]
Embodiment 9
The following describes a structural example of an application of the
transmission methods and reception methods shown in the above embodiments and
a system using the application.
[0211]
Fig. 21 shows an example of the structure of a system that includes devices
implementing the transmission methods and reception methods described in the
above embodiments. The transmission method and reception method described in
the above embodiments are implemented in a digital broadcasting system 600, as
shown in Fig. 21, that includes a broadcasting station 601 and a variety of receivers
such as a television 611, a DVD recorder 612, a Set Top Box (STB) 613, a computer
620, an in-car television 641, and a mobile phone 630.
[0212]
Specifically, the broadcasting station 601 transmits multiplexed data, in
which video data, audio data, and the like are multiplexed, using the transmission
methods in the above embodiments over a predetermined broadcasting band.
[0213]
An antenna (for example, antennas 610 and 640) internal to each receiver,
or provided externally and connected to the receiver, receives the Signal transmitted
from the broadcasting station 601. Each receiver obtains the multiplexed data by
using the reception methods in the above embodiments to demodulate the Signal
received by the antenna. In this way, the digital broadcasting system 600 obtains the
advantageous effects of the present invention described in the above embodiments.
[0214]
The video data included in the multiplexed data has been coded with a
moving Picture coding method compliant with a standard such as Moving Picture
Experts Group (MPEG)2, MPEG4-Advanced Video Coding (AVC), VC-1, or the
like. The audio data included in the multiplexed data has been encoded with an
audio coding method compliant with a standard such as Dolby Audio Coding (AC)-3,
Dolby Digital Plus, Meridian Lossless Packing (MLP), Digital Theater Systems
(DTS), DTS-HD, Pulse Coding Modulation (PCM), or the like.
[0215]
Fig. 22 is a schematic view illustrating an exemplary structure of a receiver
650 for carrying out the reception methods described in the above embodiments. The
receiver 650 shown in Fig. 22 corresponds to a component that is included, for
example, in the television 611, the DVD recorder 612, the STB 613, the computer
620, the in-car television 641, the mobile phone 630, or the like illustrated in Fig. 21.
The receiver 650 includes a tuner 651, for transforming a high-frequency Signal
received by an antenna 685 into a baseband Signal, and a demodulation unit 652, for
demodulating multiplexed data from the baseband Signal obtained by frequency
conversion. The reception methods described in the above embodiments are
implemented in the demodulation unit 652, thus obtaining the advantageous effects
of the present invention described in the above embodiments.
[0216]
The receiver 650 includes a stream input/output unit 653, a Signal
processing unit 654, an AV output unit 655, an audio output unit 656, and a video
display unit 657. The stream input/output unit 653 demultiplexes video and audio
data from multiplexed data obtained by the demodulation unit 652. The Signal
processing unit 654 decodes the demultiplexed video data into a video Signal using
an appropriate moving Picture decoding method and decodes the demultiplexed
audio data into an audio Signal using an appropriate audio decoding method. The AV
output unit 655 outputs the Signals output by the Signal processing unit 654 to other
units. The audio output unit 656, such as a speaker, produces audio output according
to the decoded audio Signal. The video display unit 657, such as a display monitor,
produces video output according to the decoded video Signal.
[0217]
For example, the user may operate the remote control 680 to select a
channel (of a TV program or audio broadcast), so that information indicative of the
selected channel is transmitted to an operation input unit 660. In response, the
receiver 650 demodulates, from among Signals received with the antenna 650, a
Signal carried on the selected channel and applies error correction decoding, so that
reception data is extracted. At this time, the receiver 650 receives control symbols
included in a Signal corresponding to the selected channel and containing
information indicating the transmission method (the transmission method,
modulation method, error correction method, and the like in the above
embodiments) of the Signal. With this information, the receiver 650 is enabled to
make appropriate settings for the receiving operations, demodulation method,
method of error correction decoding, and the like to duly receive data included in
data symbols transmitted from a broadcasting station (base station). Although the
above description is directed to an example in which the user selects a channel using
the remote control 680, the same description applies to an example in which the user
selects a channel using a selection key provided on the receiver 650.
[0218]
With the above structure, the user can view a broadcast program that the
receiver 650 receives by the reception methods described in the above embodiments.
[0219]
The receiver 650 according to this embodiment may additionally include a
recording unit (drive) 658 for recording various data onto a recording medium, such
as a magnetic disk, optical disc, or a non-volatile semiconductor memory. Examples
of data to be recorded by the recording unit 658 include data contained in
multiplexed data that is obtained as a result of demodulation and error correction by
the demodulation unit 652, data equivalent to such data (for example, data obtained
by compressing the data), and data obtained by processing the moving Pictures
and/or audio. Note that the term "optical disc" used herein refers to a recording
medium, such as Digital Versatile Disc (DVD) or BD (Blu-ray Disc), that is readable
and writable with the use of a laser beam. Further, the term "magnetic disk" used
herein refers to a recording medium, such as a floppy disk (FD, registered
trademark) or hard disk, that is writable by magnetizing a magnetic substance with
magnetic flux. Still further, the term "non-volatile semiconductor memory" refers to
a recording medium, such as flash memory or ferroelectric random access memory,
composed of semiconductor element(s). Specific examples of non-volatile
semiconductor memory include an SD card using flash memory and a flash Solid
State Drive (SSD). It should be naturally appreciated that the specific types of
recording media mentioned herein are merely examples, and any other types of
recording mediums may be usable.
[0220]
With the above structure, the user can record a broadcast program that the
receiver 650 receives with any of the reception methods described in the above
embodiments, and time-shift viewing of the recorded broadcast program is possible
anytime after the broadcast.
[0221]
In the above description of the receiver 650, the recording unit 658 records
multiplexed data obtained as a result of demodulation and error correction by the
demodulation unit 652. However, the recording unit 658 may record part of data
extracted from the data contained in the multiplexed data. For example, the
multiplexed data obtained as a result of demodulation and error correction by the
demodulation unit 652 may contain contents of data broadcast service, in addition to
video data and audio data. In this case, new multiplexed data may be generated by
multiplexing the video data and audio data, without the contents of broadcast service,
extracted from the multiplexed data demodulated by the demodulation unit 652, and
the recording unit 658 may record the newly generated multiplexed data.
Alternatively, new multiplexed data may be generated by multiplexing either of the
video data and audio data contained in the multiplexed data obtained as a result of
demodulation and error correction decoding by the demodulation unit 652, and the
recording unit 658 may record the newly generated multiplexed data. The recording
unit 658 may also record the contents of data broadcast service included, as
described above, in the multiplexed data.
[0222]
The receiver 650 described in the present invention may be included in a
television, a recorder (such as DVD recorder, Blu-ray recorder, HDD recorder, SD
card recorder, or the like), or a mobile telephone. In such a case, the multiplexed
data obtained as a result of demodulation and error correction decoding by the
demodulation unit 652 may contain data for correcting errors (bugs) in software
used to operate the television or recorder or in software used to prevent disclosure of
personal or confidential information. If such data is contained, the data is installed
on the television or recorder to correct the software errors. Further, if data for
correcting errors (bugs) in software installed in the receiver 650 is contained, such
data is used to correct errors that the receiver 650 may have. This arrangement
ensures more stable operation of the TV, recorder, or mobile phone in which the
receiver 650 is implemented.
[0223]
Note that it may be the stream input/output unit 653 that handles extraction
of data from the whole data contained in multiplexed data obtained as a result of
demodulation and error correction decoding by the demodulation unit 652 and
multiplexing of the extracted data. More specifically, under instructions given from a
control unit not illustrated in the figures, such as a CPU, the stream input/output unit
653 demultiplexes video data, audio data, contents of data broadcast service etc.
from the multiplexed data demodulated by the demodulation unit 652, extracts
specific Pieces of data from the demultiplexed data, and multiplexes the extracted
data Pieces to generate new multiplexed data. The data Pieces to be extracted from
demultiplexed data may be determined by the user or determined in advance for the
respective types of recording mediums.
[0224]
With the above structure, the receiver 650 is enabled to extract and record
only data necessary to view a recorded broadcast program, which is effective to
reduce the Size of data to be recorded.
[0225]
In the above description, the recording unit 658 records multiplexed data
obtained as a result of demodulation and error correction decoding by the
demodulation unit 652. Alternatively, however, the recording unit 658 may record
new multiplexed data generated by multiplexing video data newly yielded by
encoding the original video data contained in the multiplexed data obtained as a
result of demodulation and error correction decoding by the demodulation unit 652.
Here, the moving Picture coding method to be employed may be different from that
used to encode the original video data, so that the data Size or bit rate of the new
video data is smaller than the original video data. Here, the moving Picture coding
method used to generate new video data may be of a different standard from that
used to generate the original video data. Alternatively, the same moving Picture
coding method may be used but with different parameters. Similarly, the recording
unit 658 may record new multiplexed data generated by multiplexing audio data
newly obtained by encoding the original audio data contained in the multiplexed
data obtained as a result of demodulation and error correction decoding by the
demodulation unit 652. Here, the audio coding method to be employed may be
different from that used to encode the original audio data, such that the data Size or
bit rate of the new audio data is smaller than the original audio data.
[0226]
The process of converting the original video or audio data contained in the
multiplexed data obtained as a result of demodulation and error correction decoding
by the demodulation unit 652 into the video or audio data of a different data Size or
bit rate is performed, for example, by the stream input/output unit 653 and the Signal
processing unit 654. More specifically, under instructions given from the control unit
such as the CPU, the stream input/output unit 653 demultiplexes video data, audio
data, contents of data broadcast service etc. from the multiplexed data obtained as a
result of demodulation and error correction decoding by the demodulation unit 652.
Under instructions given from the control unit, the Signal processing unit 654
converts the demultiplexed video data and audio data respectively using a motion
Picture coding method and an audio coding method each different from the method
that was used in the conversion applied to obtain the video and audio data. Under
instructions given from the control unit, the stream input/output unit 653 multiplexes
the newly converted video data and audio data to generate new multiplexed data.
Note that the Signal processing unit 654 may conduct the conversion of either or
both of the video or audio data according to instructions given from the control unit.
In addition, the Sizes of video data and audio data to be obtained by encoding may
be specified by a user or determined in advance for the types of recording mediums.
[0227]
With the above arrangement, the receiver 650 is enabled to record video and
audio data after converting the data to a Size recordable on the recording medium or
to a Size or bit rate that matches the read or write rate of the recording unit 658. This
arrangement enables the recoding unit to duly record a program, even if the Size
recordable on the recording medium is smaller than the data Size of the multiplexed
data obtained as a result of demodulation and error correction decoding by the
demodulation unit 652, or if the rate at which the recording unit records or reads is
lower than the bit rate of the multiplexed data. Consequently, time-shift viewing of
the recorded program by the user is possible anytime after the broadcast.
[0228]
Furthermore, the receiver 650 additionally includes a stream output
interface (IF) 659 for transmitting multiplexed data demodulated by the
demodulation unit 652 to an external device via a transport medium 670. In one
example, the stream output IF 659 may be a radio communication device that
transmits multiplexed data via a wireless medium (equivalent to the transport
medium 670) to an external device by modulating the multiplexed data with in
accordance with a wireless communication method compliant with a wireless
communication standard such as Wi-Fi (registered trademark, a set of standards
including IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, and IEEE 802.1 In), WiGiG
Wireless HD, Bluetooth, ZigBee, or the like. The stream output IF 659 may also be a
wired communication device that transmits multiplexed data via a transmission line
(equivalent to the transport medium 670) Physically connected to the stream output
IF 659 to an external device, modulating the multiplexed data using a
communication method compliant with wired communication standards, such as
Ethernet (registered trademark), Universal Serial Bus (USB), Power Line
Communication (PLC), or High-Definition Multimedia Interface (HDMI).
[0229]
With the above structure, the user can use, on an external device,
multiplexed data received by the receiver 650 using the reception method described
according to the above embodiments. The usage of multiplexed data by the user
mentioned herein includes use of the multiplexed data for real-time viewing on an
external device, recording of the multiplexed data by a recording unit included in an
external device, and transmission of the multiplexed data from an external device to
a yet another external device.
[0230]
In the above description of the receiver 650, the stream output IF 659
outputs multiplexed data obtained as a result of demodulation and error correction
decoding by the demodulation unit 652. However, the receiver 650 may output data
extracted from data contained in the multiplexed data, rather than the whole data
contained in the multiplexed data. For example, the multiplexed data obtained as a
result of demodulation and error correction decoding by the demodulation unit 652
may contain contents of data broadcast service, in addition to video data and audio
data. In this case, the stream output IF 659 may output multiplexed data newly
generated by multiplexing video and audio data extracted from the multiplexed data
obtained as a result of demodulation and error correction decoding by the
demodulation unit 652. In another example, the stream output IF 659 may output
multiplexed data newly generated by multiplexing either of the video data and audio
data contained in the multiplexed data obtained as a result of demodulation and error
correction decoding by the demodulation unit 652.
[0231]
Note that it may be the stream input/output unit 653 that handles extraction
of data from the whole data contained in multiplexed data obtained as a result of
demodulation and error correction decoding by the demodulation unit 652 and
multiplexing of the extracted data. More specifically, under instructions given from a
control unit not illustrated in the figures, such as a Central Processing Unit (CPU),
the stream input/output unit 653 demultiplexes video data, audio data, contents of
data broadcast service etc. from the multiplexed data demodulated by the
demodulation unit 652, extracts specific Pieces of data from the demultiplexed data,
and multiplexes the extracted data Pieces to generate new multiplexed data. The data
Pieces to be extracted from demultiplexed data may be determined by the user or
determined in advance for the respective types of the stream output IF 659.
[0232]
With the above structure, the receiver 650 is enabled to extract and output
only data necessary for an external device, which is effective to reduce the
bandwidth used to output the multiplexed data.
[0233]
In the above description, the stream output IF 659 outputs multiplexed data
obtained as a result of demodulation and error correction decoding by the
demodulation unit 652. Alternatively, however, the stream output IF 659 may output
new multiplexed data generated by multiplexing video data newly yielded by
encoding the original video data contained in the multiplexed data obtained as a
result of demodulation and error correction decoding by the demodulation unit 652.
The new video data is encoded with a moving Picture coding method different from
that used to encode the original video data, so that the data Size or bit rate of the new
video data is smaller than the original video data. Here, the moving Picture coding
method used to generate new video data may be of a different standard from that
used to generate the original video data. Alternatively, the same moving Picture
coding method may be used but with different parameters. Similarly, the stream
output IF 659 may output new multiplexed data generated by multiplexing audio
data newly obtained by encoding the original audio data contained in the
multiplexed data obtained as a result of demodulation and error correction decoding
by the demodulation unit 652. The new audio data is encoded with an audio coding
method different from that used to encode the original audio data, such that the data
Size or bit rate of the new audio data is smaller than the original audio data.
[0234]
The process of converting the original video or audio data contained in the
multiplexed data obtained as a result of demodulation and error correction decoding
by the demodulation unit 652 into the video or audio data of a different data Size of
bit rate is performed, for example, by the stream input/output unit 653 and the Signal
processing unit 654. More specifically, under instructions given from the control unit,
the stream input/output unit 653 demultiplexes video data, audio data, contents of
data broadcast service etc. from the multiplexed data obtained as a result of
demodulation and error correction decoding by the demodulation unit 652. Under
instructions given from the control unit, the Signal processing unit 654 converts the
demultiplexed video data and audio data respectively using a motion Picture coding
method and an audio coding method each different from the method that was used in
the conversion applied to obtain the video and audio data. Under instructions given
from the control unit, the stream input/output unit 653 multiplexes the newly
converted video data and audio data to generate new multiplexed data. Note that the
Signal processing unit 654 may perform the conversion of either or both of the video
or audio data according to instructions given from the control unit. In addition, the
Sizes of video data and audio data to be obtained by conversion may be specified by
the user or determined in advance for the types of the stream output IF 659.
[0235]
With the above structure, the receiver 650 is enabled to output video and
audio data after converting the data to a bit rate that matches the transfer rate
between the receiver 650 and an external device. This arrangement ensures that even
if multiplexed data obtained as a result of demodulation and error correction
decoding by the demodulation unit 652 is higher in bit rate than the data transfer rate
to an external device, the stream output IF duly outputs new multiplexed data at an
appropriate bit rate to the external device. Consequently, the user can use the new
multiplexed data on another communication device.
[0236]
Furthermore, the receiver 650 also includes an audio and visual output
interface (hereinafter, AV output IF) 661 that outputs video and audio Signals
decoded by the Signal processing unit 654 to an external device via an external
transport medium. In one example, the AV output IF 661 may be a wireless
communication device that transmits modulated video and audio Signals via a
wireless medium to an external device, using a wireless communication method
compliant with wireless communication standards, such as Wi-Fi (registered
trademark), which is a set of standards including IEEE 802.11a, IEEE 802,11b,
IEEE 802.11g, and IEEE 802.11n, WiGiG, Wireless HD, Bluetooth, ZigBee, or the
like. In another example, the AV output IF 661 may be a wired communication
device that transmits modulated video and audio Signals via a transmission line
Physically connected to the AV output IF 661 to an external device, using a
communication method compliant with wired communication standards, such as
Ethernet (registered trademark), USB, PLC, HDMI, or the like. In yet another
example, the AV output IF 661 may be a terminal for connecting a cable to output
the video and audio Signals in analog form.
[0237]
With the above structure, the user is allowed to use, on an external device,
the video and audio Signals decoded by the Signal processing unit 654.
[0238]
Furthermore, the receiver 650 additionally includes an operation input unit
660 for receiving a user operation. According to control Signals indicative of user
operations input to the operation input unit 660, the receiver 650 performs various
operations, such as switching the power ON or OFF, switching the reception channel,
switching the display of subtitle text ON or OFF, switching the display of subtitle
text to another language, changing the volume of audio output of the audio output
unit 656, and changing the settings of channels that can be received.
[0239]
Additionally, the receiver 650 may have a function of displaying the antenna
level indicating the quality of the Signal being received by the receiver 650. Note
that the antenna level is an indicator of the reception quality calculated based on, for
example, the Received Signal Strength Indication, Received Signal Strength
Indicator (RSSI), received field strength, Carrier-to-noise power ratio (C/N), Bit
Error Rate (BER), packet error rate, frame error rate, and channel state information
of the Signal received on the receiver 650. In other words, the antenna level is a
Signal indicating the level and quality of the received Signal. In this case, the
demodulation unit 652 also includes a reception quality measuring unit for
measuring the received Signal characteristics, such as Rssi, received field strength,
C/N, BER, packet error rate, frame error rate, and channel state information. In
response to a user operation, the receiver 650 displays the antenna level (i.e., Signal
indicating the level and quality of the received Signal) on the video display unit 657
in a manner identifiable by the user. The antenna level (i.e., Signal indicating the
level and quality of the received Signal) may be numerically displayed using a
number that represents Rssi, received field strength, C/N, BER, packet error rate,
frame error rate, channel state information or the like. Alternatively, the antenna
level may be displayed using an image representing Rssi, received field strength,
C/N, BER, packet error rate, frame error rate, channel state information or the like.
When video data and audio data composing a program are transmitted hierarchically,
the receiver 650 may also display the Signal level (signal indicating the level and
quality of the received Signal) for each hierarchical level.
[0240]
With the above structure, users are able to grasp the antenna level (signal
indicating the level and quality of the received Signal) numerically or visually during
reception with the reception methods shown in the above embodiments.
[0241]
Although the receiver 650 is described above as having the audio output
unit 656, video display unit 657, recording unit 658, stream output IF 659, and AV
output IF 7911, it is not necessary for the receiver 650 to have all of these units. As
long as the receiver 650 is provided with at least one of the units described above,
the user is enabled to use multiplexed data obtained as a result of demodulation and
error correction decoding by the demodulation unit 652. The receiver 650 may
therefore include any combination of the above-described units depending on its
intended use.
Multiplexed Data
The following is a detailed description of an exemplary structure of
multiplexed data. The data structure tyPically used in broadcasting is an MPEG2
transport stream (TS), so therefore the following description is given by way of an
example related to MPEG2-TS. It should be naturally appreciated, however, that the
data structure of multiplexed data transmitted by the transmission and reception
methods described in the above embodiments is not limited to MPEG2-TS and the
advantageous effects of the above embodiments are achieved even if any other data
structure is employed.
[0242]
Fig. 23 is a view illustrating an exemplary multiplexed data structure. As
illustrated in Fig. 80, multiplexed data is obtained by multiplexing one or more
elementary streams, which are elements constituting a broadcast program
(programme or an event which is part of a program) currently provided through
respective services. Examples of elementary streams include a video stream, audio
stream, presentation graphics (PG) stream, and interactive graphics (IG) stream. In
the case where a broadcast program carried by multiplexed data is a movie, the
video streams represent main video and sub video of the movie, the audio streams
represent main audio of the movie and sub audio to be mixed with the main audio,
and the PG stream represents subtitles of the movie. The term "main video" used
herein refers to video images normally presented on a screen, whereas "sub video"
refers to video images (for example, images of text explaining the outline of the
movie) to be presented in a small window inserted within the video images. The IG
stream represents an interactive display constituted by presenting GUI components
on a screen.
[0243]
Each stream contained in multiplexed data is identified by an identifier
called P_ID uniquely assigned to the stream. For example, the video stream carrying
main video images of a movie is assigned with "0x1011", each audio stream is
assigned with a different one of "0x1100" to "OxlllF", each PG stream is assigned
with a different one of "0x1200" to "0xl21F", each IG stream is assigned with a
different one of "0x1400" to "0xl41F", each video stream carrying sub video
images of the movie is assigned with a different one of "0x1B00" to "0x1B1F", each
audio stream of sub-audio to be mixed with the main audio is assigned with a
different one of "0x1A00" to "1x1AlF".
[0244]
Fig. 24 is a schematic view illustrating an example of how the respective
streams are multiplexed into multiplexed data. First, a video stream 701 composed
of a plurality of video frames is converted into a PES packet sequence 702 and then
into a TS packet sequence 703, whereas an audio stream 704 composed of a plurality
of audio frames is converted into a PES packet sequence 705 and then into a TS
packet sequence 706. Similarly, the PG stream 711 is first converted into a PES
packet sequence 712 and then into a TS packet sequence 713, whereas the IG stream
714 is converted into a PES packet sequence 715 and then into a TS packet sequence
716. The multiplexed data 717 is obtained by multiplexing the TS packet sequences
(703, 706, 713 and 716) into one stream.
[0245]
Fig. 25 illustrates the details of how a video stream is divided into a
sequence of PES packets. In Fig. 25, the first tier shows a sequence of video frames
included in a video stream. The second tier shows a sequence of PES packets. As
indicated by arrows yyl, yy2, yy3, and yy4 shown in Fig. 25, a plurality of video
presentation units, namely I Pictures, B Pictures, and P Pictures, of a video stream
are separately stored into the payloads of PES packets on a Picture-by-Picture baS1s.
Each PES packet has a PES header and the PES header stores a Presentation
Time-Stamp (PTS) and Decoding Time-Stamp (DTS) indicating the display time and
decoding time of a corresponding Picture.
[0246]
Fig. 26 illustrates the format of a TS packet to be eventually written as
multiplexed data. The TS packet is a fixed length packet of 188 bytes and has a
4-byte TS header containing such information as P_ID identifying the stream and a
184-byte TS payload carrying actual data. The PES packets described above are
divided to be stored into the TS payloads of TS packets. In the case of BD-ROM,
each TS packet is attached with a TPExtraHeader of 4 bytes to build a 192-byte
source packet, which is to be written as multiplexed data. The TP_Extra_Header
contains such information as an Arrival_Time_Stamp (ATS). The ATS indicates a
time for starring transfer of the TS packet to the P_ID filter of a decoder. As shown on
the lowest tier in Fig. 26, multiplexed data includes a sequence of source packets
each bearing a source packet number (SPN), which is a number incrementing
sequentially from the start of the multiplexed data.
[0247]
In addition to the TS packets storing streams such as video, audio, and PG
streams, multiplexed data also includes TS packets storing a Program Association
Table (PAT), a Program Map Table (PMT), and a Program Clock Reference (PCR).
The PAT in multiplexed data indicates the P_ID of a PMT used in the multiplexed
data, and the P_ID of the PAT is "0". The PMT includes P_IDs identifying the
respective streams, such as video, audio and subtitles, contained in multiplexed data
and attribute information (frame rate, aspect ratio, and the like) of the streams
identified by the respective P_IDs. In addition, the PMT includes various types of
descriptors relating to the multiplexed data. One of such descriptors may be copy
control information indicating whether or not copying of the multiplexed data is
permitted. The PCR includes information for synchronizing the Arrival Time Clock
(ATC), which is the time axis of ATS, with the System Time Clock (STC), which is
the time axis of PTS and DTS. More specifically, the PCR packet includes
information indicating an STC time corresponding to the ATS at which the PCR
packet is to be transferred.
[0248]
Fig. 27 is a view illustrating the data structure of the PMT in detail. The
PMT starts with a PMT header indicating the length of data contained in the PMT.
Following the PMT header, descriptors relating to the multiplexed data are disposed.
One example of a descriptor included in the PMT is copy control information
described above. Following the descriptors, Pieces of stream information relating to
the respective streams included in the multiplexed data are arranged. Each Piece of
stream information is composed of stream descriptors indicating a stream type
identifying a compression codec employed for a corresponding stream, a P_ID of the
stream, and attribute information (frame rate, aspect ratio, and the like) of the stream.
The PMT includes as many stream descriptors as the number of streams included in
the multiplexed data.
[0249]
When recorded onto a recoding medium, for example, the multiplexed data
is recorded along with a multiplexed data information file.
[0250]
Fig. 28 is a view illustrating the structure of the multiplexed data
information file. As illustrated in Fig. 28, the multiplexed data information file is
management information of corresponding multiplexed data and is composed of
multiplexed data information, stream attribute information, and an entry map. Note
that multiplexed data information files and multiplexed data are in a one-to-one
relationship.
[0251]
As illustrated in Fig. 28, the multiplexed data information is composed of a
system rate, playback start time, and playback end time. The system rate indicates
the maximum transfer rate of the multiplexed data to the P_ID filter of a system target
decoder, which is described later. The multiplexed data includes ATSs at intervals set
so as not to exceed the system rate. The playback start time is set to the time
specified by the PTS of the first video frame in the multiplexed data, whereas the
playback end time is set to the time calculated by adding the playback period of one
frame to the PTS of the last video frame in the multiplexed data.
[0252]
Fig. 29 illustrates the structure of stream attribute information contained in
multiplexed data information file. As illustrated in Fig. 29, the stream attribute
information includes Pieces of attribute information of the respective streams
included in multiplexed data, and each Piece of attribute information is registered
with a corresponding P_ID. That is, different Pieces of attribute information are
provided for different streams, namely a video stream, an audio stream, a PG stream
and an IG stream. The video stream attribute information indicates the compression
codec employed to compress the video stream, the resolutions of individual Pictures
constituting the video stream, the aspect ratio, the frame rate, and so on. The audio
stream attribute information indicates the compression codec employed to compress
the audio stream, the number of channels included in the audio stream, the language
of the audio stream, the sampling frequency, and so on. These Pieces of information
are used to initialize a decoder before playback by a player.
[0253]
In the present embodiment, from among the Pieces of information included
in the multiplexed data, the stream type included in the PMT is used. In the case
where the multiplexed data is recorded on a recording medium, the video stream
attribute information included in the multiplexed data information file is used. More
specifically, the moving Picture coding method and device described in any of the
above embodiments may be modified to additionally include a step or unit of setting
a specific Piece of information in the stream type included in the PMT or in the
video stream attribute information. The specific Piece of information is for
indicating that the video data is generated by the moving Picture coding method and
device described in the embodiment. With the above structure, video data generated
by the moving Picture coding method and device described in any of the above
embodiments is distinguishable from video data compliant with other standards.
[0254]
Fig. 30 illustrates an exemplary structure of a video and audio output device
750 that includes a receiver 754 for receiving a modulated Signal carrying video and
audio data or data for data broadcasting from a broadcasting station (base station).
Note that the structure of the receiver 754 corresponds to the receiver 650 illustrated
in Fig. 22. The video and audio video output device 750 is installed with an
Operating System (OS), for example, and also with a communication device 756 (a
device for a wireless Local Area Network (LAN) or Ethernet, for example) for
establishing an Internet connection. With this structure, hypertext (World Wide Web
(WWW)) 753 provided over the Internet can be displayed on a display area 751
Simultaneously with images 752 reproduced on the display area 751 from the video
and audio data or data provided by data broadcasting. By operating a remote control
(which may be a mobile phone or keyboard) 757, the user can make a selection on
the images 752 reproduced from data provided by data broadcasting or the hypertext
753 provided over the Internet to change the operation of the video and audio video
output device 750. For example, by operating the remote control to make a selection
on the hypertext 753 provided over the Internet, the user can change the WWW Site
currently displayed to another Site. Alternatively, by operating the remote control
757 to make a selection on the images 752 reproduced from the video or audio data
or data provided by the data broadcasting, the user can transmit information
indicating a selected channel (such as a selected broadcast program or audio
broadcasting). In response, an interface (IF) 755 acquires information transmitted
from the remote control, so that the receiver 754 operates to obtain reception data by
demodulation and error correction of a Signal carried on the selected channel. At this
time, the receiver 754 receives control symbols included in a Signal corresponding to
the selected channel and containing information indicating the transmission method
of the Signal. With this information, the receiver 754 is enabled to make appropriate
settings for the receiving operations, demodulation method, method of error
correction decoding, and the like to duly receive data included in data symbols
transmitted from a broadcasting station (base station). Although the above
description is directed to an example in which the user selects a channel using the
remote control 757, the same description applies to an example in which the user
selects a channel using a selection key provided on the video and audio video output
device 750.
[0255]
In addition, the video and audio video output device 750 may be operated
via the Internet. For example, a terminal connected to the Internet may be used to
make settings on the video and audio video output device 750 for pre-programmed
recording (storing). (The video and audio video output device 750 therefore would
have the recording unit 658 as illustrated in Fig. 22.) In this case, before starting the
pre-programmed recording, the video and audio video output device 750 selects the
channel, so that the receiver 754 operates to obtain reception data by demodulation
and error correction decoding of a Signal carried on the selected channel. At this time,
the receiver 754 receives control symbols included in a Signal corresponding to the
selected channel and containing information indicating the transmission method (the
transmission method, modulation method, error correction method, and the like in
the above embodiments) of the Signal. With this information, the receiver 754 is
enabled to make appropriate settings for the receiving operations, demodulation
method, method of error correction decoding, and the like to duly receive data
included in data symbols transmitted from a broadcasting station (base station).
[0256]
Modifications
The present invention is not limited to the above-described embodiments
but rather may be implemented in any form in order to achieve the object of the
present invention or a related or associated object thereof. For example, the
following modifications are possible.
[0257]
(1) In Embodiments 1 and 2, the energy dispersion at the transmitting end
and the reverse energy dispersion at the receiving end are applied to the entire L1
signaling data, but the present invention is not limited in this way. The energy
dispersion at the transmitting end and the reverse energy dispersion at the receiving
end may be applied to only a portion of the L1 signaling data (such as the L1-post signaling data).
[0258]
In Embodiments 5 and 6, the energy dispersion at the transmitting end and
the reverse energy dispersion at the receiving end are applied to the entire L1-post
signaling data in the L1 signaling data, but the present invention is not limited in this
way. The energy dispersion at the transmitting end and the reverse energy dispersion
at the receiving end may be applied to only a portion of the L1-post signaling data,
or may be applied to the entire L1 signaling data if a mechanism is adopted to
provide notification to the receiving end, separate from the L1 signaling data,
regarding whether energy dispersion has been applied.
[0259]
(2) The poS1tions for adding a structural element that applies energy
dispersion to the L1 signaling data at the transmitting end and a structural element
that applies reverse energy dispersion to the L1 signaling data at the receiving end is
not limited to the poS1tions described in Embodiments 1, 2, 5, and 6. For example,
these structural elements may be added at the following poS1tions.
[0260]
At the transmitting end, an energy dispersion unit may be added between
the L1-pre error correction coder 1031 and the L1-pre mapper 1023, and between
the Ll-post bit interleaver 1025 and the Ll-post mapper 1026. At the receiving end,
a reverse energy dispersion unit may be added between the L1-pre demapper 1121
and the L1-pre error correction decoder 1131, and between the Ll-post demapper
1122 and the Ll-post bit deinterleaver 1123.
[0261]
At the transmitting end, an energy dispersion unit may be added between
the Ll-post bit interleaver 1025 and the Ll-post mapper 1026, and at the receiving
end, a reverse energy dispersion unit may be added between the Ll-post demapper
1122 and the Ll-post bit deinterleaver 1123.
[0262]
(3) In Embodiments 1, 2, 5, and 6, the energy dispersion units 121 and 121 A,
as well as the reverse energy dispersion units 171 and 171A, use a 15th order pseudo
random binary sequence, but the present invention is not limited in this way. The
pseudo random binary sequence may have a different number of orders. For example,
a 19th order pseudo random binary sequence or a 23rd order pseudo random binary
sequence may be used.
[0263]
Furthermore, the initial value of the 15-bit shift register 132 is not limited to
being "100101010000000" as above. The initial value may be a different value, such
as "111111111111111" or "101010101010101".
[0264]
In Embodiments 1 and 2, the initial value is assigned to the shift register
132 at the first bit of the L1-pre signaling data, but assignment is not limited in this
way. For example, the initial value may also be assigned to the shift register 132 at
the first bit of the L1-post signaling data, or the initial value may be assigned to the
shift register 132 at the first bit of each BCH/LDPC code block in the L1-post
signaling data. In Embodiments 5 and 6, the initial value is assigned to the shift
register 132 at the first bit of the L1-post signaling data, but assignment is not
limited in this way. For example, the initial value may also be assigned at the first bit
of each BCH/LDPC code block in the L1-post signaling data.
[0265]
In Embodiments 1 and 2, energy dispersion at the transmitting end and
reverse energy dispersion at the receiving end are performed with one structural
element, but the present invention is not limited in this way. For example, energy
dispersion at the transmitting end and reverse energy dispersion at the receiving end
may be divided up between L1-pre signaling data and L1-post signaling data and
performed by different structural elements. In this case, in the structural element that
performs energy dispersion and the structural element that performs reverse energy
dispersion on the L1-pre signaling data, the initial value is for example assigned to
the shift register at the first bit of the L1-pre signaling data. In the structural element
that performs energy dispersion and the structural element that performs reverse
energy dispersion on the L1-post signaling data, the initial value is for example
assigned to the shift register at the first bit of the L1-post signaling data, and may
also be assigned to the shift register at the first bit of each BCH/LDPC code block in
the L1-post signaling data.
[0266]
(4) In Embodiments 3 and 7, the L1 signaling data generators 321 and 321A
invert the bit pattern in the L1-post signaling data of the L1-post signaling data
portions (excluding the PLP_ID) pertaining to PLPs with either an even-numbered
or an odd-numbered PLP_ID. Alternatively, a method may be adopted to invert the
bit pattern of a portion of the L1 signaling data that allows for prevention of a large
bias in the mapping data of the L1-pre signaling data and the L1-post signaling data,
such as inversion of the bit pattern of L1-post signaling data portions (excluding the
PLP_ID) pertaining to a portion of PLPs. In this case, the L1 signaling data
analyzers 371 and 371A in the receivers 350 and 350A make determinations in
accordance with the bit pattern inversion by the L1 signaling data generators 321
and 321 A. Note that the portion of PLPs may be the PLPs whose PLP_ID is in the
earlier half of the PLP_IDs or whose PLP_ID is in the later half. Furthermore, the
number of the portion of PLPs need not be half the total number of PLPs.
[0267]
(5) In Embodiments 4 and 8, the L1 signaling data generators 421 and 421A
switch on use of the L1-post extension field and fill a predetermined number of bits
with 1 's or with 0's, but the present invention is not limited in this way. A large bias
in the mapping data of the L1-pre signaling data and the L1-post signaling data may
be prevented by filling a predetermined number of bits with 1 's and a predetermined
number of bits with 0's.
[0268]
(6) Either a portion or the entirety of each of the integrated circuits 151,
151A, 251, 251A, 351, 351A, 451, and 451A in Embodiments 1 through 8 may be
integrated into one chip.
[0269]
All or a portion of the structural elements of the transmitters 100,100 A, 200,
200A, 300, 300A, 400, and 400A in Embodiments 1 through 8 may be formed as an
integrated circuit. In this case, either a portion or the entirety of the integrated circuit
may be integrated into one chip.
[0270]
In Embodiments 1 through 8, the integrated circuits 151, 151A, 251, 251A,
351, 351 A, 451, and 451A include the structural elements other than the antenna
1111 and the tuner 1112 of the receivers 150, 150A, 250, 250A, 350, 350A, 450, and
450A respectively, but the integrated circuits are not limited in this way. The
integrated circuits may include the structural elements other than the antenna 1111,
or a portion of the structural elements other than the antenna 1111 and the tuner 1112.
In this case, either a portion or the entirety of the integrated circuit may be integrated
into one chip. Furthermore, the receivers 150, 150A, 250, 250A, 350, 350A, 450,
and 450A need not be made into integrated circuits.
[0271]
The above integrated circuits are, for example, implemented as an LS1.
Although referred to here as an LS1, depending on the degree of integration, the
terms IC, system LS1, super LS1, or ultra LS1 are also used. In addition, the method
for assembling integrated circuits is not limited to LS1, and a dedicated
communication circuit or a general-purpose processor may be used. An FPGA,
which is programmable after the LS1 is manufactured, or a reconfigurable processor,
which allows reconfiguration of the connection and setting of circuit cells inside the
LS1, may be used. Furthermore, if technology for forming integrated circuits that
replace LS1s emerges, owing to advances in semiconductor technology or to another
derivative technology, the integration of functional blocks may naturally be
accomplished using such technology. The application of biotechnology or the like is
possible.
[0272]
(8) Embodiments 1 through 8 describe transmitters and receivers based on
the DVB-T2 standard, but the present invention is not limited in this way. A
transmitter and a receiver that apply the present invention to a future transmission
format, such as DVB-NGH, may be provided.
[0273]
(9) S1nce Embodiments 1 through 8 describe transmitters and receivers
based on the DVB-T2 standard, error correction coding based on BCH coding and
LDPC coding is performed at the transmitting end, and error correction decoding
based on BCH decoding and LDPC decoding is performed at the receiving end. The
present invention is not, however, limited in this way. Different codes may be used,
such as a Reed Solomon code and a convolutional code. Furthermore, it is not
necessary to use two codes. The number of codes used may be one, or may be three
or greater.
[0274]
(10) S1nce Embodiments 4 and 8 describe transmitters and receivers based
on the DVB-T2 standard, the extension field that is used is the L1-post extension
field of the L1-post signaling data. The present invention is not, however, limited in
this way. For example, if Embodiments 4 and 8 are applied to a different format, the
extension field specified by that format would be used.
[0275]
(11) A program listing steps for a transmission method and a reception
method according to Embodiments 1 through 8 may be stored in a program memory.
A CPU may read the program from the program memory and execute the read
program.
[0276]
(12) Embodiments 1 through 8 and modifications thereto may be combined
as needed.
[Industrial Applicability]
[0277]
The transmitter, transmission method, receiver, reception method, integrated
circuit, and program according to the present invention are particularly useful with
the DVB standard.
[Reference Signs List]
[0278]
100, 200, 300,400, 1000 transmitter
100A, 200A, 300A, 400A, 1000A transmitter
111,211,311,411 L1 signaling data coder
111A,211A,311A,411A L1 signaling data coder
121,121A energy dispersion unit
126 energy dispersion control unit
131 combination unit
132 shift register
133,134 EXOR circuit
135 distribution unit
136 selector
150, 250, 350,450,1100 receiver
150A,250A,350A,450A receiver
151,251, 351,451 integrated circuit
151 A, 251A, 351A, 451A integrated circuit
161, 261, 361, 1117 L1 signaling data decoder
161 A, 261 A, 361A L1 signaling data decoder
171, 171A reverse energy dispersion unit
176 reverse energy dispersion control unit
321, 421, 1021 L1 signaling data generator
321A, 421A, 1021A L1 signaling data generator
371,371A, 1125, 1125A L1 signaling data analyzer
600 digital broadcast system
601 broadcasting station
610, 640, 685 antenna
611 television
612 recorder
613 STB
620 computer
630 mobile phone
641 in-car television
650 receiver
651 tuner
652 demodulation unit
653 stream input/output unit
654 S1gnal processing unit
655 AV output unit
656 audio output unit
657 video display unit
658 recording unit
659 stream output interface
660 operation input unit
661 AV output IF
670,675 medium
680 remote control
701 video stream
702, 705, 712, 715 PES packet sequence
703,706,713,716 TS packet
704 audio stream
711 presentation graphics stream
714 interactive graphics
717 multiplexed data
750 video and audio output device
751 area for displaying video
752 video images
753 hypertext
754 receiver
755 IF
756 communication device
757 remote control
1011 main Signal coder
1013 frame builder
1014 OFDM Signal generator
1022 L1 error correction coder
1023 L1-pre mapper
1025 L1-post bit interleaver
1026 L1 -post mapper
1031 L1 -pre error correction coder
1032 L1-post error correction coder
1111 antenna
1112 tuner
1113 A/D converter
1114 OFDM demodulator
1115 selected PLP/L1 signaling data extraction unit
1116 main Signal decoder
1121 L1-pre demapper
1122 L1 -post demapper
1123 L1-post bit deinterleaver
1124 L1 error correction decoder
1131 L1 -pre error correction decoder
1132 L1 -post error correction decoder
WE CLAIM
1. A transmitter comprising:
an L1 (Layer-1) signaling data generator configured to generate, from
transmission parameters of a main Signal, L1 signaling data storing the transmission
parameters;
an energy dispersion and error correction coding unit configured to perform
energy dispersion on at least a portion of the L1 signaling data output by the L1
signaling data generator and to perform error correction coding on the L1 signaling
data; and
a mapper configured to perform mapping on the energy-dispersed, error
correction coded L1 signaling data output by the energy dispersion and error
correction coding unit, wherein
the L1 signaling data is divided into L1-pre signaling data and L1-post signaling data, the L1-post
signaling data storing the total number of the PLPs,
the L1 signaling data generator stores, in the L1-pre signaling data, energy
dispersion information indicating whether energy dispersion has been performed,
and
the energy dispersion and error correction coding unit performs the energy
dispersion on the L1-post signaling data only when information indicating that
energy dispersion has been performed is stored in the L1-pre signaling data.
2. A receiver for receiving L1 (Layer-1) signaling data storing transmission
parameters of a main Signal,
energy dispersion having been performed on at least a portion of the L1
signaling data, and error correction coding having been performed on the entire L1 signaling data,
the receiver comprising:
an error correction decoding and reverse energy dispersion unit configured
to reproduce the L1 signaling data by performing error correction decoding on a
received Signal and performing reverse energy dispersion on at least a portion of the
received Signal; and
an L1 signaling data analyzer configured to analyze the reproduced L1
signaling data output by the error correction decoding and reverse energy dispersion
unit and to output transmission parameters, wherein
the L1 signaling data is divided into L1-pre signaling data and L1-post
signaling data, the Ll-post signaling data storing the total number of the PLPs,
energy dispersion information indicating whether energy dispersion has
been performed is stored in the L1-pre signaling data,
the energy dispersion has only been performed on the Ll-post signaling data,
and
the error correction decoding and reverse energy dispersion unit performs
the reverse energy dispersion on the Ll-post signaling data only when the energy
dispersion information indicates that the energy dispersion has been performed.
3.. A transmission method comprising the steps of:
(a) generating, from transmission parameters of a main Signal, L1 (Layer-1)
signaling data storing the transmission parameters;
(b) performing energy dispersion on at least a portion of the L1 signaling
data generated in step (a) and performing error correction coding on the L1 signaling
data; and
(c) performing mapping on the L1 signaling data that is energy-dispersed
and error correction coded in step (b) wherein
the L1 signaling data is divided into L1-pre signaling data and Ll-post
signaling data, the Ll-post signaling data storing the total number of the PLPs,
in step (a), energy dispersion information indicating whether energy
dispersion has been performed is stored in the L1-pre signaling data, and
in step (b), the energy dispersion is performed on the Ll-post signaling data
only when information indicating that energy dispersion has been performed is
stored in the L1-pre signaling data.
4. A reception method for receiving L1 (Layer-1) signaling data storing
transmission parameters of a main Signal,
energy dispersion having been performed on at least a portion of the L1
signaling data, and error correction coding having been performed on the entire L1 signaling data,
the reception method comprising the steps of:
(a) reproducing the L1 signaling data by performing error correction
decoding on a received Signal and performing reverse energy dispersion on at least a
portion of the received Signal; and
(b) analyzing the L1 signaling data reproduced in step (a) and outputting
transmission parameters, wherein
the L1 signaling data is divided into L1-pre signaling data and L1-post
signaling data, the L1-post signaling data storing the total number of the PLPs,
energy dispersion information indicating whether energy dispersion has
been performed is stored in the L1-pre signaling data,
the energy dispersion has only been performed on the L1-post signaling data,
and
in step (a), the reverse energy dispersion is performed on the L1-post
signaling data only when the energy dispersion information indicates that the energy
dispersion has been performed.

ABSTRACT

A transmitter 100 includes an L1 signaling data coder 111. In the L1
signaling data coder 111, an L1 signaling data generator 1021 converts transmission
parameters into L1-pre signaling data and L1-post signaling data and outputs the
L1-pre signaling data and the L1-post signaling data, an energy dispersion unit 121
performs energy dispersion on the L1-pre signaling data and the L1-post signaling
data in order, and an L1 error correction coder 1022 performs error correction
coding, based on BCH coding and LDPC coding, on the energy-dispersed L1-pre
signaling data. This allows for randomization of a large bias in mapping data of the
L1-pre signaling data and the L1-post signaling data, thus solving the problem of
concentration of power in a specific sample within P2 symbols.