Integrated Multi-datastream Transmission Technology
Field of the invention
The present disclosure relates to wireless communication technology,
more particularly, to integrated multi-datastream modulation technology.
Background of the invention
Hierarchical modulation (HM) technology is used to transmit different
data streams together, for example, a first data stream and a second data
stream. From the point of view of constellation diagram, hierarchical
modulation modulates an upgrade constellation (namely second data
stream) on the basis of a primary constellation (namely first data stream).
FIG. l shows a kind of constellation map of 16QAM hierarchical
modulation in prior art. This constellation map includes 16 constellations
as shown by 16 black points. Any modulation symbol, which includes 4
bits, can be mapped into one of the 16 constellations. The front two bits in
the modulation symbol correspond to a first data stream, while the last
two bits correspond to a second data stream. The constellations
corresponding to the modulation symbols of the same first data stream are
located in the same quadrant. Such 16QAM hierarchical modulation may
be considered as the sum of two QPSK constellations, wherein a first data
stream corresponds to a primary QPSK constellation as shown by four
diagonal circles, while a second data stream corresponds to an upgrade
QPSK constellation as shown by four constellations in each quadrants
(relative to the diagonal circle in the quadrant).
Dirty Paper Coding (DPC) modulation technology has a constellation
mapping feature similar to hierarchical modulation, constellation map of
which may also be consider as the sum of a primary constellation and an
upgrade constellation. In the prior art, a technology scheme has been
proposed that the data stream of unicast service and the data stream of
multimedia broadcast service (MBMS) are transmitted together based on
the Dirty Paper Coding modulation technology in the Orthogonal
Frequency Division Multiplexing (OFDM) system, wherein, the unicast
service data stream corresponds to a first data stream, while the MBMS
data stream corresponds to a second data stream. Such technology scheme
is based on the following assumption: Multiple base stations work on a
single frequency network (SFN) manner for MBMS data stream.
However, there also exists a need for the technology scheme that
multiple data streams (e.g., unicast service data stream and MBMS data
stream) are transmitted together in case of single cell network
environment.
Summary of the invention
FIG.2 shows the simulation result of the modulation scheme of the
16QAM hierarchical modulation and 16QAM DPC in the prior art. The
simulation conditions are as followed: Maximum transmission power of
base station (BS) is 43dBm, Bandwidth is 5MHz, Subcarrier space is
15Hz, FFT size is 512, Inter site distance is 500m, Strength ratio of a first
data stream to second data stream is 2, Turbo code with the code rate of
1/3 has been applied for the coding scheme, Two-stage QPSK as shown in
FIG. l has been applied for the modulation scheme, Log-map algorithm
has been applied for the decoding, AWGN has been applied for the
channel condition and Ideal channel estimation has been applied for the
channel estimation scheme. In FIG.2 abscissa represents the ratio of the
average power E of the 16QAM symbols to noise power spectrum density
N0, while vertical coordinate represents bit error rate. As shown in the
figure, the performance curve with triangle marks is for the first data
stream in case of 16QAM hierarchical modulation scheme, the
performance curve with quadrel marks is for the second data stream in
case of 16QAM hierarchical modulation scheme, the performance curve
with strigula marks is for the first data stream in case of 16QAM DPC
modulation scheme and the performance curve with cross marks is for the
second data stream in case of 16QAM DPC modulation scheme. As shown
in FIG.2, there is an apparent performance difference between the first
data stream and the second data stream in case of 16QAM hierarchical
modulation scheme and 16QAM DPC modulation scheme. For a second
data stream (e.g., MBMS data stream), the received power of the second
data stream at user equipment may be compensated due to the sum of the
signal from multiple base stations to improve the reception performance
of a second data stream when multiple base stations work on a single
frequency network manner.
However, the apparent performance difference between a first data
stream and a second data stream cannot be overcome by using hierarchical
modulation technology or DPC modulation technology in the prior art in
single cell network environment. The reception performance of a second
data stream may be unbearable so that the integrated multi-datastream
transmission loses its desired effects.
Thus there exists a need for a new technology scheme to reduce or
eliminate the performance gap for multiple data streams in BER in order
to enable multiple data streams to be transmitted integrated in single cell
network environment.
According to one aspect of the present invention, there is provided a
modulation equipment, comprising: a symbol integration means,
configured to combine a first bit stream with a second bit stream to form a
symbol to be modulated; a symbol mapping means, configured to map the
symbol to be modulated into a QAM modulation symbol according to a
set of predetermined mapping rules; wherein, in the set of predetermined
mapping rules, multiple constellations corresponding to any first bit
stream are located in at least two quadrants in the constellation diagram,
while multiple constellations corresponding to any second bit stream are
located in at least two quadrants in the constellation diagram.
According to another aspect of the present invention, there is provided
a modulation method, wherein, said method comprises steps of:
combining a first bit stream with a second bit stream to form a symbol to
be modulated; mapping the symbol to be modulated into a QAM
modulation symbol according to a set of predetermined mapping rules;
wherein, in the set of predetermined mapping rules, multiple
constellations corresponding to any first bit stream are located in at least
two quadrants in the constellation diagram, while multiple constellations
corresponding to any second bit stream are located in at least two
quadrants in the constellation diagram.
According to a further aspect of the present invention, there is
provided a transmitter for transmitting integrated multi-datastream signal,
comprising: a subcarrier mapping equipment, configured to transform first
type of service data stream(s) into a first bit stream corresponding to each
subcarrier; a Serial/Parallel converter, configured to transform a second
type of service data stream into a second bit stream corresponding to each
subcarrier; a modulation equipment, configured to combine the first bit
stream and the second bit stream corresponding to each subcarrier to form
a symbol to be modulated, and to map the symbol to be modulated into a
QAM modulation symbol according to a set of predetermined mapping
rules; a signal forming equipment, configured to generate OFDM signal
according to the QAM symbol in each subcarrier.
According to a still further aspect of the present invention, there is
provided a method of transmitting integrated multiple service data in a
base station in a wireless communication system, wherein, said method
comprises steps of: broadcasting indication information related to an
integrated service data, wherein the indication information includes a set
of predetermined mapping rules and the integrated service data includes a
first type of service data and a second type of service data; transmitting
the scheduling information of the first type of service and the signaling of
the second type of service; combining a first type of service data and a
second type of service data according to the set of predetermined mapping
rules, to generate integrated service data; transmitting the integrated
service data.
The integrated transmission of a first type of service data and a second
type of service data (e.g., unicast service data and MBMS data) may be
supported and has a better performance than the prior art especially in
single cell network environment by using the method, equipment and
device in the present invention.
Brief description of drawings
With reference to the following detailed description of the
non-restrictive embodiments, other features, objects and advantages of the
present invention will be more apparent;
FIG. l shows a kind of constellation map of 16QAM hierarchical
modulation in prior art;
FIG.2 shows the simulation result of the modulation scheme of the
16QAM hierarchical modulation and 16QAM DPC in the prior art;
FIG.3 shows a block diagram of a modulation equipment according to
an embodiment of the present invention;
FIG.4 shows a flowchart of a modulation method according to an
embodiment of the present invention;
FIG.5a, 5b, 5c and 5d respectively shows a 16QAM constellation map
according to an respective embodiment of the present invention;
FIG.6 shows a block diagram of a transmitter for transmitting
integrated multi-datastream signal according to an embodiment of the
present invention;
FIG.7 shows a method flowchart of an integrated multi-datastream
transmission in a wireless communication system according to an
embodiment of the present invention;
Wherein, throughout different figures, same or similar reference
numerals refer to corresponding features.
Detailed description of embodiments
FIG.3 shows a block diagram of a modulation equipment according
to an embodiment of the present invention. As shown, modulation
equipment 10 includes symbol integration means 101 and symbol
mapping means 102. Modulation equipment 10 is typically set in the
transmitter, which transmits integrated multi-datastream signal.
Symbol integration means 101 is configured to combine a first bit
stream with a second bit stream to form a symbol to be modulated.
Symbol mapping means 102 is configured to map the symbol to be
modulated into a QAM modulation symbol according to a set of
predetermined mapping rules.
Wherein, in the set of predetermined mapping rules, multiple
constellations corresponding to any first bit stream are located in at least
two quadrants in the constellation diagram, while multiple constellations
corresponding to any second bit stream are located in at least two
quadrants in the constellation diagram.
FIG.4 shows a flowchart of a modulation method according to an
embodiment of the present invention. As shown, the modulation method
includes two steps S101 and SI 02. The modulation method is typically
implemented in the transmitter, which transmits integrated
multi-datastream signal.
In step S101, a first bit stream and a second bit stream are combined to
form a symbol to be modulated.
In step SI 02, the symbol to be modulated is mapped into a QAM
modulation symbol according to a set of predetermined mapping rules.
Wherein, in the set of predetermined mapping rules, multiple
constellations corresponding to any first bit stream are located in at least
two quadrants in the constellation diagram, while multiple constellations
corresponding to any second bit stream are located in at least two
quadrants in the constellation diagram.
Modulation equipment 10 shown in FIG.3 is generally used to execute
the modulation method shown in FIG.4. Symbol integration means 101 is
used to execute step S101 and symbol mapping means 102 is used to
execute step SI 02. The set of predetermined mapping rules are generally
stored in the memory of the transmitter (e.g., base station) or the receiver
(e.g., user equipment).
According to an embodiment of the present invention, 16QAM is
applied for the modulation scheme. One symbol includes four bits
information, wherein a first bit stream and a second bit stream occupies
two bits respectively.
According to an embodiment of the present invention, 64QAM is
applied for the modulation scheme. One symbol includes six bits
information, wherein the information ratio may be: a first bit stream
occupies four bits and a second bit stream occupies two bits; or both a
first bit stream and a second bit stream occupy three bits; or a first bit
stream occupies two bits and a second bit stream occupies four bits.
According to other embodiments of the present invention, 32QAM and
128QAM etc. may also be applied for the modulation scheme. The ratio of
a first bit stream to a second bit stream in a symbol may also be adjusted
according to the demand.
As described above, 16QAM hierarchical modulation in the prior art
as shown in FIG. l may be considered as the sum of two QPSK
constellations. A first data stream corresponds to an primary QPSK
constellation as shown by four diagonal circles, while a second data
stream corresponds to an upgrade QPSK constellation as shown by four
constellations in each quadrants (relative to the diagonal circle in the
quadrant). From intuitive point of view, the constellations corresponding
to the modulation symbols of the same first data stream are located in the
same quadrant, and the constellation distance of the primary QPSK
constellation is greater than the constellation distance of the upgrade
QPSK constellation. Explained from the point of view of energy, the
average energy per bit of a first data stream is higher than the average
energy per bit of a second data stream, so that it causes the difference of
the reception performance (BER) between a first data stream and a second
data stream.
In the set of predetermined mapping rules in the present invention,
multiple constellations corresponding to any first bit stream are located in
at least two quadrants in the constellation diagram, while multiple
constellations corresponding to any second bit stream are located in at
least two quadrants in the constellation diagram. A first bit stream and a
second bit stream are integrated as an entire to be mapped to the complex
plane without the feature of the sum of two low-dimension QAM or
QPSK in hierarchical modulation or DPC modulation of the prior art, so
that the difference between the average energy per bit of a first data
stream and the average energy per bit of a second data stream is reduced
or even eliminated. Therefore the difference of the reception performance
(BER) between a first data stream and a second data stream may also be
reduced or even eliminated.
According to some embodiments of the present invention, in the
modulation equipment 10 as shown in FIG.3, or in the modulation method
as shown in FIG.4, a first bit stream includes unicast service data, while a
second bit stream includes MBMS data.
According to some embodiments of the present invention, the
modulation equipment 10 as shown in FIG.3 and the modulation method
as shown in FIG4 are applied in single cell network environment.
According to an embodiment of the present invention, 16QAM is
applied for the modulation scheme and the constellation map
corresponding to the set of predetermined mapping rules is shown in
FIG.5a . One symbol includes four bits information, wherein a first bit
stream and a second bit stream occupies two bits respectively. A symbol is
represented as a bit sequence bob^b^ in this embodiment, a first bit
stream corresponds to bob , while a second bit stream corresponds to b2b3.
As shown, four symbols, of which the first bit stream is 10, are symbol
1000, 1001, 1010 and 101 1. The corresponding four constellations are
respectively located in the second quadrant and the third quadrant in the
complex plane and the pattern constructed by these four constellations is a
rectangle which is symmetrical relative to the x axis of the complex plane
and the long side of which is parallel to the y axis of the complex plane.
Similarly, the pattern constructed by the four constellations corresponding
to the four symbols, of which the first bit stream is 00, the pattern
constructed by the four constellations corresponding to the four symbols,
of which the first bit stream is 0 1 and the pattern constructed by the four
constellations corresponding to the four symbols, of which the first bit
stream is 11, are also a rectangle. Four symbols, of which the second bit
stream is 00, are symbol 1000, 1100, 0000 and 0100. The corresponding
four constellations are respectively located in the first quadrant and the
second quadrant in the complex plane and the pattern constructed by these
four constellations is a rectangle which is symmetrical relative to the y
axis of the complex plane and the long side of which is parallel to the x
axis of the complex plane. Similarly, the pattern constructed by the four
constellations corresponding to the four symbols, of which the second bit
stream is 0 1, the pattern constructed by the four constellations
corresponding to the four symbols, of which the second bit stream is 10
and the pattern constructed by the four constellations corresponding to the
four symbols, of which the second bit stream is 11, are also a rectangle. In
this embodiment, the patterns constructed by the constellations
corresponding to the symbols with a same first bit stream constitute a first
set of patterns, which includes four rectangles; the patterns constructed by
the constellations corresponding to the symbols with a same second bit
stream constitute a second set of patterns, which also includes four
rectangles; any pattern in the first set of patterns and a corresponding
pattern in the second set of patterns are symmetrical relative to line y=x or
line y=-x by pairs in the complex plane in the constellation diagram.
According to another embodiment of the present invention, 16QAM is
applied for the modulation scheme and the constellation map
corresponding to the set of predetermined mapping rules is shown in
FIG.5b. One symbol includes four bits information, wherein a first bit
stream and a second bit stream occupies two bits respectively. A symbol is
represented as a bit sequence bobibibs, in this embodiment, a first bit
stream corresponds to bobi, while a second bit stream corresponds to b2b3.
As shown, four symbols, of which the first bit stream is 10, are symbol
1000, 100 1, 10 10 and 101 1. The corresponding four constellations are
respectively located in the second quadrant and the third quadrant in the
complex plane and the pattern constructed by these four constellations is a
rectangle which is not symmetrical relative to the x axis of the complex
plane and the long side of which is parallel to the y axis of the complex
plane. Similarly, the pattern constructed by the four constellations
corresponding to the four symbols, of which the first bit stream is 00, the
pattern constructed by the four constellations corresponding to the four
symbols, of which the first bit stream is 0 1 and the pattern constructed by
the four constellations corresponding to the four symbols, of which the
first bit stream is 11, are also a rectangle. Four symbols, of which the
second bit stream is 00, are symbol 1000, 1 00, 0000 and 0100. The
corresponding four constellations are respectively located in the first
quadrant and the second quadrant in the complex plane and the pattern
constructed by these four constellations is a rectangle which is not
symmetrical relative to the y axis of the complex plane and the long side
of which is parallel to the x axis of the complex plane. Similarly, the
pattern constructed by the four constellations corresponding to the four
symbols, of which the second bit stream is 01, the pattern constructed by
the four constellations corresponding to the four symbols, of which the
second bit stream is 10 and the pattern constructed by the four
constellations corresponding to the four symbols, of which the second bit
stream is 11, are also a rectangle. In this embodiment, the patterns
constructed by the constellations corresponding to the symbols with a
same first bit stream constitute a first set of patterns, which includes four
rectangles; the patterns constructed by the constellations corresponding to
the symbols with a same second bit stream constitute a second set of
patterns, which also includes four rectangles; any pattern in the first set of
patterns and a corresponding pattern in the second set of patterns are
symmetrical relative to line y=x or line y=-x by pairs in the complex plane
in the constellation diagram.
According to a further embodiment of the present invention, 16QAM
is applied for the modulation scheme and the constellation map
corresponding to the set of predetermined mapping rules is shown in
FIG.5c. One symbol includes four bits information, wherein a first bit
stream and a second bit stream occupies two bits respectively. A symbol is
represented as a bit sequence bob b2b3, in this embodiment, a first bit
stream corresponds to bobi, while a second bit stream corresponds to b2b3.
As shown, four symbols, of which the first bit stream is 10, are symbol
1000, 100 1, 1010 and 101 1. The corresponding four constellations are
respectively located in the second quadrant and the third quadrant in the
complex plane and the pattern constructed by these four constellations is a
line parallel to y axis in the complex plane. Similarly, the pattern
constructed by the four constellations corresponding to the four symbols,
of which the first bit stream is 00, the pattern constructed by the four
constellations corresponding to the four symbols, of which the first bit
stream is 0 1 and the pattern constructed by the four constellations
corresponding to the four symbols, of which the first bit stream is 11, are
also a line parallel to y axis in the complex plane. Four symbols, of which
the second bit stream is 00, are symbol 1000, 1100, 0000 and 0100. The
corresponding four constellations are respectively located in the first
quadrant and the second quadrant in the complex plane and the pattern
constructed by these four constellations is a line parallel to x axis in the
complex plane. Similarly, the pattern constructed by the four
constellations corresponding to the four symbols, of which the second bit
stream is 0 1, the pattern constructed by the four constellations
corresponding to the four symbols, of which the second bit stream is 10
and the pattern constructed by the four constellations corresponding to the
four symbols, of which the second bit stream is 11, are also a line parallel
to x axis in the complex plane. In this embodiment, the patterns
constructed by the constellations corresponding to the symbols with a
same first bit stream constitute a first set of patterns, which includes four
lines parallel to y axis in the complex plane; the patterns constructed by
the constellations corresponding to the symbols with a same second bit
stream constitute a second set of patterns, which also includes four lines
parallel to x axis in the complex plane; any pattern in the first set of
patterns and a corresponding pattern in the second set of patterns are
symmetrical relative to line y=x or line y=-x by pairs in the complex plane
in the constellation diagram.
According to an embodiment of the present invention, 16QAM is
applied for the modulation scheme and the constellation map
corresponding to the set of predetermined mapping rules is shown in
FIG.5d. One symbol includes four bits information, wherein a first bit
stream and a second bit stream occupies two bits respectively. A symbol is
represented as a bit sequence bobib2b3, in this embodiment, a first bit
stream corresponds to bob , while a second bit stream corresponds to b2b3.
As shown, four symbols, of which the first bit stream is 10, are symbol
1000, 1001, 1010 and 101 1. The corresponding four constellations are
respectively located in the four quadrants in the complex plane and the
pattern constructed by these four constellations is a trapezoid of which the
upper bottom and lower bottom are parallel to x axis in the complex plane.
Similarly, the pattern constructed by the four constellations corresponding
to the four symbols, of which the first bit stream is 00, the pattern
constructed by the four constellations corresponding to the four symbols,
of which the first bit stream is 0 1 and the pattern constructed by the four
constellations corresponding to the four symbols, of which the first bit
stream is 11, are also a trapezoid. Four symbols, of which the second bit
stream is 00, are symbol 1000, 1100, 0000 and 0100. The corresponding
four constellations are respectively located in the four quadrants in the
complex plane and the pattern constructed by these four constellations is a
trapezoid of which the upper bottom and lower bottom are parallel to y
axis in the complex plane. Similarly, the pattern constructed by the four
constellations corresponding to the four symbols, of which the second bit
stream is 0 1, the pattern constructed by the four constellations
corresponding to the four symbols, of which the second bit stream is 10
and the pattern constructed by the four constellations corresponding to the
four symbols, of which the second bit stream is 11, are also a trapezoid. In
this embodiment, the patterns constructed by the constellations
corresponding to the symbols with a same first bit stream constitute a first
set of patterns, which includes four trapezoids; the patterns constructed by
the constellations corresponding to the symbols with a same second bit
stream constitute a second set of patterns, which also includes four
trapezoids; any pattern in the first set of patterns and a corresponding
pattern in the second set of patterns are symmetrical relative to line y=x or
line y=-x by pairs in the complex plane in the constellation diagram.
Above FIGs. 5a, 5b, 5c and 5d have shown 16QAM constellation
mapping. The amount of information for a first bit stream is as same as
the amount of information for a second bit stream (both two bits). The
four predetermined mapping rules as described above all meet the
following two conditions: (1) Multiple constellations corresponding to
any first bit stream are located in at least two quadrants in the
constellation diagram, while multiple constellations corresponding to any
second bit stream are located in at least two quadrants in the constellation
diagram; (2) the constellation distribution patterns corresponding to a first
bit stream and the constellation distribution patterns corresponding to a
second bit stream are symmetrical relative to line y=x or line y=-x,
wherein, x and y represent the coordinate axis in the complex plane of the
constellation diagram. Because both of the two conditions described
above have been met at the same time, especially the second condition has
been met, there is no relationship of high or low level between a first bit
stream and a second bit stream any more, so that the difference between
the average energy per bit of a first data stream and a second data stream
is reduced or even eliminated. Therefore, the difference of the reception
performance (BER) between a first data stream and a second data stream
will be also reduced or even eliminated. It is intelligible to those skilled in
the art that, various predetermined mapping rules which meet the two
conditions described above at the same time may also be designed for the
situation in which the amount of information for a first bit stream is as
same as the amount of information for a second bit stream, for example,
the situation in which a first bit stream and a second bit stream occupies
two bits respectively when modulated by 16QAM, or the situation in
which a first bit stream and a second bit stream occupies three bits
respectively when modulated by 64QAM.
FIG.6 shows a block diagram of a transmitter for transmitting
integrated multi-datastream signal according to an embodiment of the
present invention. As shown, the transmitter in this embodiment includes:
Serial/Parallel converter 7, subcarrier mapping equipment 8, modulation
equipment 10 and signal forming equipment 9.
In OFDM system, data signal are carried in frequency band(s).
Integrated multi-datastream signal will be carried in the same
time-frequency resources. In each frequency band, the total bandwidth is
divided into multiple subcarriers which are orthogonal with each other. As
shown in FIG.6, in this embodiment, a first type of service data and a
second type of service data, for example, unicast service data and MBMS
data, are transmitted in integration. In a certain frequency band, MBMS
data stream is transmitted over all the frequency band, and second bit
streams corresponding to each subcarrier are generated from MBMS data
stream by means of the transformation of S/P converter 7; each unicast
service data stream corresponds one or more subcarriers allocated for
carrying signal, and first bit streams corresponding to each subcarrier are
generated from a number of unicast service data streams by means of the
process of subcarrier mapping equipment 8.
For a first bit stream and a second data stream on each subcarrier,
symbol integration means 101 in modulation equipment 10 is configured
to combine a first bit stream with a second bit stream to form a symbol to
be modulated. Symbol mapping means 102 in modulation equipment 10 is
configured to map the symbol to be modulated into a QAM modulation
symbol according to the set of predetermined mapping rules. Wherein, in
the set of predetermined mapping rules, multiple constellations
corresponding to any first bit stream are located in at least two quadrants
in the constellation diagram, while multiple constellations corresponding
to any second bit stream are located in at least two quadrants in the
constellation diagram. For example, but not limited to, the set of
predetermined mapping rules here corresponds to any constellation map
shown in FIG 5a, 5b, 5c and 5d. After the process described above,
modulation equipment 10 generates QAM symbols on each subcarrier.
Signal forming equipment 9 is configured to combine control
signaling with QAM symbols on each subcarrier generated by modulation
equipment 10 together so as to generate OFDM signal of this frequency
band.
FIG.7 shows a method flowchart of an integrated multi-datastream
transmission in a wireless communication system according to an
embodiment of the present invention.
The system includes base station 1, first user equipment 2 and second
user equipment 3 as shown.
Base station 1, for example, but not limited to, evolved Node B (eNB),
includes generally a transmitter as shown in FIG.6 for transmitting
integrated multi-datastream. There may exist first user equipment(s) 2 to
receive a first type of service, for example, but not limited to, unicast
service. There may exist multiple second user equipments 3 to receive a
second type of service, for example, but not limited to, MBMS. In this
embodiment, single cell transmission mode is applied for a second type of
service.
Without loss of generality, a first type of service and a second type of
service are integrated in a certain time unit and the length of the time unit
of the integrated service is defined by the system. Based on the scheduling,
base station 1 decides to involve the service(s) of first user equipment(s) 2
in integration with a second type of service. In the time unit, the set of
predetermined mapping rules applied for the integration of a first type of
service data and a second type of service data corresponds to, for example,
but not limited to, the constellation maps shown in FIG.5a,5b,5c and 5d.
In step Sl l , base station 1 will broadcast indication information
related to an integrated service data, the indication information including
when to execute the set of predetermined mapping rules and the applied
modulation scheme etc. Wherein, indication information is also used to
indicate which first user equipments are involved into the integrated
service.
In step S121 , base station 1 will transmit the signaling of a second
type of service to second user equipment 3.
In step SI22, base station 1 will transmit the scheduling information
of the first type of service to first user equipment 2.
In step SI3, base station 1 will combine a first type of service data and
a second type of service data according to a set of predetermined mapping
rules, to generate integrated service data. The process includes application
of the modulation method as shown in FIG.4.
In step SI4, base station 1 will transmit the integrated service data.
On the side of the first user equipment 2, the following procedures
will be executed correspondingly.
In step S21 (not shown), first user equipment 2 will receive the
indication information related to an integrated service data and determine
whether the integrated service data includes its first type of service data.
If the integrated service data includes its first type of service data, first
user equipment 2 will continue to execute the following procedures.
In step S22 (not shown), first user equipment 2 will receive the
scheduling information of the first type of service.
In step S23, first user equipment 2 will receive the integrated service
data according to the indication information related to the integrated
service data and the scheduling information of the first type of service,
and demodulate its first type of service data therein.
On the side of the second user equipment 3, the following procedures
will be executed correspondingly.
In step S3 1 (not shown), second user equipment 3 will receive the
indication information related to an integrated service data and determine
whether the integrated service data includes its second type of service
data. If the integrated service data includes its second type of service data,
second user equipment 3 will continue to execute the following
procedures.
In step S32 (not shown), second user equipment 3 will receive the
signaling of a second type of service and determine whether to receive the
transmitting second type of service. If determined to receive the
transmitting second type of service, step S33 will be continued to be
executed.
In step S33, second user equipment 3 will receive an integrated service
data according to the indication information related to the integrated
service data and the scheduling information of a second type of service,
and demodulate the second type of service data therein.
According to an embodiment of the present invention, in the cell of
the base station 1, interference coordination technology is applied for a
first type of service, for example, unicast service. Specifically, the system
divides the frequency resource to a number of reuse sets and allocates the
user to each reuse set by using power control method; the users located in
the center of the cell may transmit and receive by using lower power and
are allocated to the reuse set with the reuse factor of 1; the users located
in the edge of the cell need to transmit and receive with higher power and
are allocated to the reuse set with the reuse factor greater than 1 (for
example, 3, 7). The users located respectively in the edge of the
neighboring cells are allocated to the different reuse sets. Therefore,
before the step S11 as described above, it is necessary for the system to
determine, in a certain cell, that the first type of service data of which first
user equipments will be combined with a second type of service data to be
transmitted together.
Without loss of generality, the method, equipment and device in the
present invention may be applied in Long Term Evolution (LTE) system.
It is intelligible to those skilled in the art that, the method, equipment and
device in the present invention may also be applied to other systems.
Following conditions have been applied to proceed the simulation
experiment: In single cell scenario, unicast data and MSMS service data
are transmitted in integration by applying the modulation scheme of
16QAM constellation maps as shown in FIG.5a and 5c and 16QAM DPC
modulation scheme in the prior art, respectively. The link layer simulation
result by applying the modulation schemes shown in FIG. 5a and 5c
indicates that link layer simulation performance for the two situations is
very close. In the system level simulation experiment, when applying the
modulation scheme as shown in FIG.5a, both MBMS coverage ( defined
as the percentage of UEs with MBMS packet error rate below 0.01) and
effective frequency efficiency are better than the simulation result when
applying 16QAM DPC modulation in the prior art. When applying the
modulation scheme as shown in FIG.5a, there are no explicit impacts on
the simulation results for different unicast service user equipments
selection schemes, for example, random selection or selection of unicast
service user equipments with maximum feedback of the channel quality
indicator (CQI).
It is intelligible to those skilled in the art that, various equipments in
the present invention could be realized by hardware module, by function
module in the software and also by hardware module integrated with
software function module.
It is intelligible to those skilled in the art that, the embodiments
described above are exemplary but not limited. Different technology
features appearing in different embodiments can be combined so as to
implement beneficial effects. Based on the research of the drawings,
specification and claims, it is intelligible to those skilled in the art that,
the alternative embodiments of these disclosed embodiments could be
implemented. In the claims, term "include" doesn't exclude other
equipments or steps; an indefinite article "a" doesn't exclude multiple;
terms "first" and "second" are used to indicate name other than any
specific order. Any drawings indicator in the claims should not be
understood as the limitation to the protection scope. The function of
multiple parts appearing in the claims can be implemented by a single
hardware or software. Certain technology features appearing in the
different subordinate claims don't mean that these technology features
cannot be combined so as to acquire beneficial effects.
CLAIMS
1.A modulation equipment, comprising:
a symbol integration means, configured to combine a first bit stream
with a second bit stream to form a symbol to be modulated;
a symbol mapping means, configured to map the symbol to be
modulated into a QAM modulation symbol according to a set of
predetermined mapping rules;
wherein, in the set of predetermined mapping rules, multiple
constellations corresponding to any first bit stream are located in at least two
quadrants in the constellation map, multiple constellations corresponding to
any second bit stream are located in at least two quadrants in the constellation
map.
2. A modulation equipment according to claim 1, wherein, in the set of
predetermined mapping rules, the constellation distribution patterns
corresponding to a first bit stream and the constellation distribution patterns
corresponding to a second bit stream are symmetrical relative to line y=x or
line y=-x, wherein, x and y represent the coordinate axis in the complex plane
of the constellation map.
3. A modulation equipment according to claim 2, wherein, in the set of
predetermined mapping rules, patterns constructed by multiple constellations
corresponding to any first bit stream or any second bit stream include
rectangle or line.
4. A modulation equipment according to any one of claims 1 to 3,
wherein, the first bit stream includes unicast service data, the second bit
stream includes multimedia broadcast multicast service data.
5. A modulation equipment according to claim 4, wherein, the
modulation equipment is disposed in single cell scenario.
6.A modulation method, comprising steps of:
combining a first bit stream with a second bit stream to form a symbol
to be modulated;
mapping the symbol to be modulated into a QAM modulation symbol
according to a set of predetermined mapping rules;
wherein, in the set of predetermined mapping rules, multiple
constellations corresponding to any first bit stream are located in at least two
quadrants in the constellation map, multiple constellations corresponding to
any second bit stream are located in at least two quadrants in the constellation
map.
7. A modulation method according to claim 6, wherein, in the set of
predetermined mapping rules, the constellation distribution patterns
corresponding to a first bit stream and the constellation distribution patterns
corresponding to a second bit stream are symmetrical relative to line y=x or
line y=-x, wherein, x and y represent the coordinate axis in the complex plane
of the constellation map.
8. A modulation method according to claim 7, wherein, in the set of
predetermined mapping rules, patterns constructed by multiple constellations
corresponding to any first bit stream or any second bit stream include
rectangle or line.
9.A modulation method according to any one of claims 6 to 8, wherein,
the first bit stream includes unicast service data, the second bit stream
includes multimedia broadcast multicast service data.
10. A modulation method according to claim 9, wherein, the
modulation method is applied in single cell scenario.
11. A transmitter for transmitting integrated multi-datastream signal,
comprising:
a subcarrier mapping equipment, configured to transform first type of
service data stream(s) into a first bit stream corresponding to each subcarrier;
a Serial/Parallel converter, configured to transform a second type of
service data stream into a second bit stream corresponding to each subcarrier;
a modulation equipment, configured to combine the first bit stream and
the second bit stream corresponding to each subcarrier to form a symbol to be
modulated, and to map the symbol to be modulated into a QAM modulation
symbol according to a set of predetermined mapping rules;
a signal forming equipment, configured to generate OFDM signal
according to the QAM symbol in each subcarrier.
12. A transmitter according to claim 11, wherein, the first type of
service data includes unicast service data, the second type of service data
includes multimedia broadcast multicast service data.
13. A method of transmitting integrated multiple service data in a base
station in a wireless communication system, comprising steps of:
broadcasting indication information related to an integrated service
data, wherein the indication information includes a set of predetermined
mapping rules and the integrated service data includes a first type of service
data and a second type of service data;
transmitting the scheduling information of the first type of service and
the signaling of the second type of service;
combining a first type of service data and a second type of service data
according to the set of predetermined mapping rules, to generate integrated
service data;
transmitting the integrated service data.
14. A method according to claim 13, wherein, the first type of service
data includes unicast service data, the second type of service data includes
multimedia broadcast multicast service data.