JP5622646B2 - Transmitting apparatus, receiving apparatus, wireless communication apparatus, and wireless communication method - Google Patents

Description

  The present invention relates to a multiple-input multiple-output (MIMO) system or a single-input multiple-output (SIMO) system that transmits multiple types of data streams in parallel, and in particular, data with different priorities (importance). The present invention relates to a transmission device, a reception device, a wireless communication device, and a wireless communication method of a system for transmitting streams in parallel.

  As a conventional system for transmitting a plurality of types of data streams in parallel, there is a wireless communication system described in Patent Document 1.

  The wireless communication system described in Patent Document 1 is a combination of space / time coding and a MIMO system. The processing on the transmission side and the processing on the reception side in this system will be briefly described as follows.

  On the transmission side, a basic stream (hereinafter referred to as high priority data) transmitted at a rate that can be received by all users, and an extended stream (hereinafter referred to as a rate that can be received by some users with good channel conditions). Symbol data is generated by performing error correction coding processing, interleaver processing, and mapping processing on each of the data. Then, space / time encoding processing is performed on each of the symbol data corresponding to the high priority data and the symbol data corresponding to the low priority data. The space / time encoding processing here means transmission diversity processing or spatial multiplexing processing. Further, a combination process is performed on the symbol data of the high priority data and the low priority data after the space / time encoding process, and transmission data for each transmission antenna is generated. The combination processing here means time division multiplexing (TDM) or superposition processing, and is processing for combining high priority data and low priority data in units of transmission antennas. . The TDM in this combining process assigns high priority data and low priority data to different time slots, and the superposition process is performed by multiplying each of the high priority data and low priority data by a weighting coefficient. Are multiplexed.

  On the other hand, on the reception side, high-priority data symbol data and low-priority data symbol data are restored based on reception data received by a plurality of reception antennas according to the combining process used on the transmission side. . Then, the restored high-priority data symbol data and low-priority data symbol data are subjected to spatial / temporal decoding processing according to the spatial / temporal encoding processing used on the transmission side. Mapping processing, deinterleaver processing, and error correction decoding processing are performed to demodulate high priority data and low priority data.

  As described above, in the wireless communication system described in Patent Document 1, the high priority data and the low priority data are applied to the high priority data and the low priority data by independently applying the space / time encoding process. Hierarchical coding is realized in the sense that different error rate performance and throughput performance can be obtained for each degree data. That is, in the space / time encoding process used on the transmission side, the fact that the error rate performance and the throughput performance change depending on whether the transmission diversity process is selected or the spatial multiplexing process is selected is used.

Japanese Patent No. 4509116

  In the conventional wireless communication system described above, hierarchical coding is realized by applying space / time coding processing to high priority data and low priority data independently of each other. The processing is performed on the assumption that data transmitted from a plurality of transmission antennas can be received on the receiving side. However, in general, in wireless communication, data transmitted from each transmission antenna cannot always be received at the receiving side. In a wireless communication system that transmits data with different priorities, it is desirable that at least high priority data be demodulated even if some of the data transmitted from each transmission antenna cannot be received. .

The present invention has been made in view of the above, and when transmitting high priority data from N _t (N _t ≧ 1) transmission antennas, K _t (0 <K _t <N _t ) Even when signals transmitted from a plurality of transmission antennas, that is, signals transmitted from some of the transmission antennas cannot be received at the receiving side, some of the received signals (transmitted from N _t −K _t transmission antennas) It is an object of the present invention to obtain a transmission device, a reception device, a wireless communication device, and a wireless communication method that can demodulate high priority data based on the received signal.

  In order to solve the above-described problems and achieve the object, the present invention is a transmission apparatus that transmits high priority data and low priority data using a plurality of transmission antennas, and supports the high priority data. As a configuration for generating a transmission sequence to be transmitted, an error correction encoding means for error correction encoding the high priority data, and an information bit sequence of the high priority data after error correction encoding is copied and the Copying means for generating the same number of information bit sequences as a plurality of transmission antennas, and the check bit sequence after the permutation of the check bit sequence among the high priority data after error correction coding A rearrangement unit that generates a sequence capable of decoding the information bit sequence using a part of the information bit sequence, and the number of sequences generated by the rearrangement unit is the same as the number of the transmission antennas And dividing the information bit sequence so that the information bit sequence can be decoded using each of the divided sequences, and further combining any one of the divided sequences with the information bit sequence output from the copying means to obtain a high priority. High-priority transmission sequence generation means for generating a data transmission sequence for each transmission antenna.

  According to the transmitting apparatus of the present invention, even when a signal transmitted from a certain transmitting antenna cannot be received on the receiving side, information bits and check bits are allocated so that error correction decoding can be performed in units of transmitting antennas. Therefore, on the receiving side, if the signal transmitted from at least one transmission antenna can be received, the high priority data can be decoded.

FIG. 1-1 is a diagram illustrating a configuration example of a first embodiment of a transmission device included in a wireless communication device according to the present invention. FIG. 1-2 is a diagram illustrating a configuration example of a first embodiment of a receiving device included in a wireless communication device according to the present invention. FIG. 2 is a diagram illustrating a configuration example of the error correction coding unit. FIG. 3 is a diagram illustrating an example of mapping. FIG. 4 is a diagram illustrating a configuration example of a receiving apparatus according to the second embodiment. FIG. 5A is a diagram illustrating a configuration example of a transmission apparatus according to the third embodiment. FIG. 5-2 is a diagram illustrating a configuration example of a receiving device according to the third embodiment. FIG. 6 is a diagram illustrating another configuration example of the receiving apparatus according to the third embodiment. FIG. 7-1 is a diagram illustrating a configuration example of a transmission apparatus according to the fourth embodiment. FIG. 7-2 is a diagram of a configuration example of the receiving apparatus according to the fourth embodiment.

  Embodiments of a transmission device, a reception device, a wireless communication device, and a wireless communication method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1-1 is a diagram illustrating a configuration example of Embodiment 1 of a transmission device included in a wireless communication device according to the present invention, and FIG. 1-2 is a reception device included in the wireless communication device according to the present invention. It is a figure which shows the structural example of this Embodiment 1. FIG. In the present embodiment, a plurality of types of data (high priority) are transmitted from the wireless communication apparatus including the transmission apparatus illustrated in FIG. 1-1 to the wireless communication apparatus including the reception apparatus illustrated in FIG. An example of transmitting data and low priority data) will be described. In FIGS. 1-1 and 1-2, stream # 1 is a high priority data stream, and stream # 2 is a low priority data stream.

1-1 includes an error correction encoding unit 101, 102, a copy unit 111, a rearrangement unit 112, a plurality of interleavers 121, an interleaver 122, a division unit 130, a plurality of symbol mapping units 141, and A plurality of transmission antennas 151 are provided, and the number of interleavers 121 and symbol mapping units 141 is equal to the number of transmission antennas 151 (N _t ). In addition, the error correction coding unit 101, the copy unit 111, the rearrangement unit 112, and the interleaver 121 perform processing on the high priority data stream, and the error correction coding unit 102, the interleaver 122, and the division unit 130 Processes for low priority data streams.

1-2 includes error correction decoding units 201 and 202, likelihood combining unit 211, rearrangement unit 212, a plurality of deinterleavers 221, a deinterleaver 222, a plurality of demapping units 231, A MIMO equalization unit 240 and a plurality of reception antennas 251 are provided, and the number of deinterleavers 221 and demapping units 231 is equal to the number of transmission antennas 151 provided by the transmission-side wireless communication device (transmission device) (N _t ). The number of receiving antennas 251 is _Nr . Further, the error correction decoding unit 201, the likelihood combining unit 211, the rearrangement unit 212, and the deinterleaver 221 perform processing on the high priority data stream, and the error correction decoding unit 202 and the deinterleaver 222 perform processing. Processes for low priority data streams.

In the transmission apparatus of FIG. 1-1, the error correction encoding unit 101 performs error correction encoding processing on high priority data. The information bit sequence is output to the copy unit 111, and the check bit sequence that is a redundant bit sequence is output to the rearrangement unit 112. The error correction encoding unit 102 performs error correction encoding processing for low priority data. Copy unit 111 generates an input signal (information bit sequence) copied the same number of streams and the number of transmit antennas N _t by the error correction coding unit 101. Rearranger 112 rearranges the input signal (check bit sequence) from error correction encoder 101. At this time, the receiving side performs rearrangement so that the information bit sequence copied by the copy unit 111 can be decoded using a part of the check bit sequence after rearrangement. Each interleaver 121 generates a transmission bit sequence by combining the information bit sequence input from the copy unit 111 and the check bit sequence input from the rearrangement unit 112, and further interleaves the transmission bit sequence. Note that the interleaver 121 operates as a high-priority transmission sequence generation unit. The interleaver 122 interleaves the encoded sequence of low priority data that is a transmission bit sequence input from the error correction encoding unit 102. The dividing unit 130 divides the encoded sequence of the low priority data after the interleaving process so as to be allocated to each transmission antenna 151. The dividing unit 130 operates as a low priority transmission sequence generation unit. The symbol mapping unit 141 synthesizes the high-priority data and low-priority data encoded sequences (sequences input from the interleaver 121 and sequences input from the dividing unit 130) allocated to each transmission antenna 151. Perform processing and mapping processing.

  In the receiving apparatus of FIG. 1, MIMO equalization section 240 performs propagation path estimation using the received signal received by each receiving antenna 251, performs equalization processing on the received signal, and transmits a spatially multiplexed signal. The data is separated into symbol data for each antenna 151. The demapping unit 231 performs demapping processing on the symbol data for each transmission antenna 151 subjected to MIMO equalization, and calculates likelihood information per bit. The deinterleaver 221 individually deinterleaves the likelihood information corresponding to the high priority data among the likelihood information per bit calculated in the demapping process for each transmission antenna 151. The deinterleaver 222 deinterleaves the likelihood information for the low priority data among the likelihood information per bit calculated by the demapping process. Likelihood synthesizer 211 is copied by the same data transmitted from each transmission antenna 151 of the transmission apparatus, ie, copy section 111 of the transmission apparatus, out of the likelihood information of the high priority data after deinterleaving. The likelihood information of the data (corresponding to the above information bit sequence) is synthesized by the number of transmission antennas in bit units. The rearrangement unit 212 out of the likelihood information of the high priority data after deinterleaving is divided by the transmission device and assigned to each transmission antenna 151, that is, the rearrangement unit 112 of the transmission device. The likelihood information of the data (corresponding to the check bit sequence described above) rearranged so as to be assigned for each transmission antenna 151 is rearranged so as to be restored to the rearrangement process of the rearrangement unit 112 of the transmission apparatus. A rearrangement process is performed (the reverse process of the rearrangement unit 112 is performed). The error correction decoding unit 201 corresponds to the error correction encoding process performed by the error correction encoding unit 101 of the transmission apparatus on the likelihood information of the high priority data after being combined by the likelihood combining unit 211. High-priority data is restored by performing error correction decoding processing. The error correction decoding unit 202 performs error correction encoding processing performed by the error correction encoding unit 102 of the transmission apparatus on the likelihood information of the low priority data after the rearrangement unit 112 performs the rearrangement. The corresponding error correction decoding process is performed to restore the low priority data.

Hereinafter, specific configurations and operations will be described in detail with respect to unique components that perform characteristic processing in the transmission device and the reception device illustrated in FIGS. In the present embodiment and each of the embodiments described later, a case where the number of transmission antennas N _t = 2 and the number of reception antennas N _r = 4 will be described for ease of explanation. However, the present invention is not limited to the number of transmission / reception antennas. Note that when two transmission antennas are distinguished, one of them will be described as transmission antenna # 1 and the other as transmission antenna # 2.

<Error Correction Encoding Unit 101>
The error correction encoding unit 101 of the transmission apparatus performs error correction encoding processing for high priority data. As an example, an operation when using a turbo code having a coding rate R _H = 1/3 will be described. However, the error correction code and coding rate used in the present invention are not limited to this.

FIG. 2 is a diagram illustrating a configuration example of the error correction coding unit 101, specifically, a block configuration diagram for a turbo code having a coding rate R _H = 1/3. The error correction encoding unit 101 includes an interleaver 301 and recursive systematic convolutional encoding units 302 and 303. Stream # 1 (high priority data) that is input to the error correction coding unit 101 is input to the recursive systematic convolutional coding unit 302, and interleaver 301 interleaves the recursive systematic convolutional coding unit 303. Stream # 1 after being input. The turbo encoder which is the error correction encoding unit 101 shown in FIG. 2 performs systematic error correction encoding on stream # 1. That is, for input high priority data {d _H }, an information bit sequence {x _H } and a check bit (redundant bits for performing error correction decoding on the receiving side) sequences {c 1 _H } and {c 2 _H } Is output.

<Copy unit 111>
The copy unit 111 of the transmission apparatus generates a copy for the number of transmission antennas, that is, N _t = 2 for the information bit sequence {x _H } of the high priority data generated by the error correction coding unit 101. To do. Here, it is assumed that the information bit sequence of the copied high priority data is {x1 _H }, {x2 _H }.

<Reordering unit 112>
The rearrangement unit 112 of the transmission apparatus combines the check bit sequence {c1 _H } and {c2 _H } of the high priority data generated by the error correction encoding unit 101 with the information bit sequence {x _H }. Rearrangement processing is performed so that error correction decoding is possible. In the rearrangement process, check bit sequences {c1 _H } and {c2 _H } are converted into {c1 _H } = a ₁ , a ₂ , a ₃ ,..., A _M , {c _{1 H} } = b ₁ , b ₂ , b _When defined as ₃ ,..., B _M , for example, it is represented by the following equation (1).

Here, {y1 _H } is a rearrangement check bit sequence for transmission antenna # 1 (a check bit sequence transmitted from transmission antenna # 1 and subjected to rearrangement), and {y2 _H } is an rearrangement for transmission antenna # 2. This is a replacement check bit sequence. M is the check bit sequence length output from the error correction coding unit 101 and is defined by the following equation (2). In Expression (2), N is the code length of the code generated by the error correction coding unit 101.

By performing the rearrangement shown in the above equation (1), decoding processing can be performed for each transmission antenna by combining with the information bit sequence. That is, decoding processing is possible only with the information bit sequence {x1 _H } transmitted from the transmission antenna # 1 and the rearrangement check bit sequence {y1 _H }, and the information bit sequence {x2 _H transmitted from the transmission antenna # 2 is possible. } And the rearrangement check bit sequence {y2 _H } only, the decoding process can be performed.

<Interleaver 121>
The interleaver 121 of the transmission device performs an interleaving process on the information bit sequence and the reordering check bit sequence of the high priority data allocated for each transmission antenna. Since N _t = 2 here, the interleaving process is performed using the information bit sequence {x1 _H } of the high priority data allocated for the transmission antenna # 1 and the reordering check bit sequence {y1 _H }, and the transmission antenna # Interleave processing is performed with the information bit sequence {x2 _H } of the high priority data allocated for 2 and the reordering check bit sequence {y2 _H }. The sequence for the transmission antenna # 1 after the interleaving is {z1 _H } and {z2 _H } for the transmission antenna # 2.

<Division unit 130>
The division unit 130 of the transmission apparatus divides the sequence {y _L } obtained by performing the error correction coding process by the error correction coding unit 102 and the interleaving by the interleaver 122 on the low priority data, Allocate to transmit antenna. Here, since N _t = 2, the sequence {y _L } is divided into two. When the sequence {y _L } = s ₁ , s ₂ , s ₃ ,..., S _J is defined, a specific example of the division process can be expressed by the following equation (3). In the following equation (3), J is the code length of the code generated by the error correction coding unit 102.

<Symbol mapping unit 141>
The symbol mapping unit 141 of the transmission device performs symbol generation processing and mapping processing on the high priority data sequence and the low priority data sequence allocated to the transmission antenna. Here, since N _t = 2, the symbol mapping unit 141 corresponding to the transmission antenna # 1 performs symbol generation processing and mapping processing with the high priority data sequence {z1 _H } and the low priority data sequence {z1 _L }. The symbol mapping unit 141 corresponding to the transmission antenna # 2 performs symbol generation processing and mapping processing using the high priority data sequence {z2 _H } and the low priority data sequence {z2 _L }.

  Here, specific operations of the symbol generation process and the mapping process will be described. First, the symbol generation process will be described. In the symbol generation process, the high priority data series and the low priority data series are synthesized to generate symbol data. Here, in order to facilitate the explanation of the operation, as an example, it is assumed that 6-bit symbol data is generated, and the symbol data includes high-priority data 2 bits and low-priority data 4 bits. In this case, the symbol data is generated according to the following equation (4).

Here, {s1} is symbol data for the transmission antenna # 1, and {s2} is symbol data for the transmission antenna # 2. H ₁ and h ₂ are 2 bits of the high priority data sequence {z1 _H } in the transmission antenna # 1, and l ₁ , l ₂ , l ₃ , and l ₄ are low priority data in the transmission antenna # 1. It is 4 bits of the sequence {z1 _L }. Further, h ₁ ′ and h ₂ ′ are 2 bits of the high priority data sequence {z2 _H } in the transmission antenna # 2, and l ₁ ′, l ₂ ′, l ₃ ′, and l ₄ ′ are transmission antenna #. 4 of the low priority data series {z2 _L } in 2.

  Next, the mapping process will be described. In the mapping process, a signal point position is determined for symbol data obtained by symbol data generation, and a transmission symbol is generated. FIG. 3 shows an example of mapping. In FIG. 3, one point is tentatively determined from the upper 2 bits, that is, 2 bits of the high priority data, from the black circle signal point representing QPSK, and the black circle tentatively determined from the lower 4 bits, that is, 4 bits of the low priority data as described above. One point is determined from the white circle signal points representing 16QAM arranged around the signal point. Thus, 2 bits of high priority data are simultaneously mapped to QPSK represented by black circle signal points, and 4 bits of low priority data are simultaneously mapped to 16 QAM represented by white circle signal points. Here, the mapping method (PSK, FSK, ASK, QAM, etc.) used in the mapping process is merely an example, and the mapping method used for the high priority data and the low priority data is not particularly limited.

<MIMO equalization unit 240>
The MIMO equalization unit 240 of the receiving apparatus applies a MIMO equalization technique (zero forcing method, minimum mean square error (Minimum Mean)) to received symbols received by N _r = 4 reception antennas 251. By using the Square Error) method, etc., the transmission symbols transmitted from N _t = 2 transmission antennas are restored.

<Demapping unit 231>
The demapping unit 231 of the receiving apparatus performs likelihood information per bit for the high priority data and the low priority data by demapping processing on the transmission symbol for each transmission antenna restored by the MIMO equalization unit 240. Generate. Here, the likelihood information includes a hard decision value in addition to a soft decision value such as a log likelihood ratio (Log Likelihood Ratio). Further, the demapping unit 231 outputs the likelihood information per bit for the high priority data obtained to the next deinterleaver for each transmission antenna to which the high priority data is transmitted.

<Deinterleaver 221>
The deinterleaver 221 of the reception device deinterleaves the likelihood information per bit for the high priority data for each transmission antenna independently for each transmission antenna. Of the likelihood information per bit for the high priority data after deinterleaving, the likelihood information of information bits is output to likelihood combining section 211, and the likelihood information of check bits is output to rearrangement section 212.

<Likelihood combiner 211>
The likelihood combining unit 211 of the receiving apparatus combines likelihood information in information bits of high priority data transmitted from each transmission antenna for all transmission antennas. Information on the likelihood of information bits of the high priority data transmitted from the transmission antenna # 1 is {r1 _info } = u ₁ , u ₂ ,..., U _K , and information on the high priority data transmitted from the transmission antenna # 2. When the bit likelihood information is {r2 _info } = v ₁ , v ₂ ,..., V _K and K is the information bit length of the high priority data, the processing by the likelihood combining unit 211 is expressed by the following equation (5). Indicated by

  Here, f (u, v) is a majority function for u and v, and when u and v are hard decision values of u = 0, 1, and v = 0, 1, respectively, the majority function f (u, v) Outputs the result of taking a majority vote of 0 and 1 for u and v. However, when the numbers 0 and 1 are the same with respect to u and v, either 0 or 1 may be output. As shown in Expression (5), when the likelihood information is a log likelihood ratio, likelihood combining is performed by accumulating the likelihood information for the number of transmission antennas, and when the likelihood information is a hard decision value, the transmission antenna is used. A majority decision is made on the likelihood information for several minutes.

<Reordering unit 212>
The reordering section 212 of the receiving apparatus reorders the likelihood information of the check bits for the high priority data so as to restore the original information by performing a process reverse to the reordering process of the reordering section 112 on the transmission side. . Check the likelihood information of the check bits of the high priority data transmitted from the transmission antenna # 1 {r1 _check } = p ₁ , p ₂ ,..., P _L , and check the high priority data transmitted from the transmission antenna # 2. When the bit likelihood information is {r2 _check } = q ₁ , q ₂ ,..., QL, the rearrangement process by the rearrangement unit 212 is expressed by the following equation (6). In the following equation (6), {t _H } is a check bit sequence for high priority data after rearrangement processing, and L is a check bit sequence length for high priority data per transmission antenna.

  As described above, in the radio communication apparatus according to the present embodiment, the transmission side (transmission apparatus) copies the information bit sequence of the high priority data for the transmission antenna and also transmits the check bit sequence of the high priority data for each transmission antenna. To divide. At this time, the combination of the information bit sequence of high priority data and the check bit sequence assigned in units of transmission antennas divides the check bit sequence so that error correction decoding can be performed in units of transmission antennas (assigned to each transmission antenna). As a result, on the receiving side (receiving apparatus), for high priority data, the same information bit sequence is transmitted from each transmitting antenna, and therefore the likelihood information of the information bit sequence of each transmitting antenna is combined with likelihood. The check bit sequence is rearranged because different data is transmitted for each transmission antenna. Thereafter, error correction decoding processing is performed using the obtained information bit sequence and likelihood information of the check bit sequence, thereby decoding high priority data. Here, the transmission side assigns information bits and check bits so that error correction decoding can be performed in units of transmission antennas even if a signal transmitted from a certain transmission antenna cannot be received on the reception side. On the receiving side, if the signal transmitted from at least one transmission antenna can be received, the high priority data can be decoded. Further, since the radio communication device on the receiving side can decode high priority data without determining whether or not a signal transmitted from a certain transmission antenna has been received, the circuit scale can be reduced. This is because the transmission signal that could not be received inevitably has a very low likelihood as its likelihood information, and the bit having a low likelihood in the error correction decoding process does not greatly affect the decoding performance. Is used.

Embodiment 2. FIG.
The receiving-side radio communication apparatus (receiving apparatus) of Embodiment 1 does not determine whether or not the signal transmitted from each transmitting antenna has been received, and performs demodulation processing assuming that all transmitted signals have been received. Do. This utilizes the fact that the likelihood of a transmission signal that could not be received becomes very low. However, even if the likelihood is very low, it has a likelihood, which is a cause of deterioration in decoding performance. Therefore, in the present embodiment, the receiving side has a function of determining whether or not the signal transmitted from each transmitting antenna can be received at a level exceeding the specified threshold, and the likelihood regarding the signal determined to be unreceivable. Setting zero to zero prevents degradation of decoding performance.

  Details of the receiving apparatus according to the present embodiment will be described below. Note that the configuration and operation of the transmission apparatus are the same as those of the transmission apparatus of the first embodiment, and a description thereof will be omitted.

  FIG. 4 is a diagram illustrating a configuration example of a receiving apparatus according to the second embodiment. The part different from the receiving apparatus of Embodiment 1 (see FIG. 1-2) is a part in which a transmission antenna validity determining unit 421 is additionally inserted after the deinterleaver 221. In this embodiment, only the operation different from that of the receiving apparatus of Embodiment 1, that is, the operation of transmitting antenna validity determining section 421 will be described.

<Transmission antenna validity determination unit 421>
The transmission antenna validity determination unit 421 uses the likelihood information in bit units for the high priority data transmitted from each transmission antenna to determine whether or not the transmission signal from each transmission antenna has been received at a level exceeding a specified threshold. judge. If reception is not possible at a level exceeding the specified threshold, the corresponding likelihood information is set to zero for all bits for high priority data transmitted from the corresponding transmission antenna. The likelihood information here means a soft decision value.

The number of transmission antennas N _t = 2 and the likelihood information of the encoded bit sequence (information bit sequence + check bit sequence) of the high priority data transmitted from the transmission antenna # 1 is {u1 _code } = e ₁ , e ₂ ,..., E _N , the likelihood information of the encoded bit sequence (information bit sequence + check bit sequence) of the high priority data transmitted from the transmitting antenna # 2 is represented by {u2 _code } = f ₁ , f ₂ ,. It will be described as f _N.

  First, transmission antenna validity determination section 421 accumulates likelihood information of coded bit sequences for each transmission antenna according to the following equation (7).

  If the cumulative results U1 and U2 for the likelihood information for each transmission antenna are equal to or less than the specified threshold values, respectively, it is determined that the transmission signal from the corresponding transmission antenna could not be received. That is, when the threshold used for transmitting antenna validity determination is TH, if U1 ≦ TH, it is determined that the transmission signal from transmitting antenna # 1 could not be received, and the likelihood information of the encoded bit sequence of transmitting antenna # 1 Are all set to zero as shown in the following equation (8).

  Similarly, when U2 ≦ TH, it is determined that the transmission signal from the transmission antenna # 2 cannot be received, and the likelihood information of the encoded bit sequence of the transmission antenna # 2 is all as shown in the following equation (9). Set to zero.

  If U1> TH, it is determined that the transmission signal from transmission antenna # 1 has been received, and the likelihood information of the encoded bit sequence of transmission antenna # 1 is output as it is. Similarly, when U2> TH, it is determined that the transmission signal from transmission antenna # 2 has been received, and the likelihood information of the encoded bit sequence of transmission antenna # 2 is output as it is.

  As described above, the transmission antenna validity determination is performed for each transmission antenna. This is because a situation is assumed in which a shielding object enters between the transmission antenna and the reception antenna, and radio waves transmitted from the transmission antenna are blocked or attenuated.

  Here, the coding gain of the error correction code for the high priority data when it is determined that a signal transmitted from a certain transmission antenna cannot be received will be described with a specific example.

For example, it is assumed that an error correction code having a coding rate of 1/3 is used for high priority data on the transmission side. When the number of transmission antennas N _t = 2, on the transmission side, as described in the first embodiment, high priority data is encoded at a coding rate of 1/3, and information bits are copied to transmit antennas # 1, The check bits are rearranged to be decodable in combination with the information bits and assigned to the transmitting antennas # 1 and # 2. At this time, the combination of the information bit and the check bit of the high priority data distributed to the transmission antenna # 1 is an encoded sequence for an error correction code with an encoding rate of 1/2, and the transmission antenna # 2 is similarly encoded. This is an encoded sequence for an error correction code with a conversion rate of 1/2. Here, it is assumed that a signal transmitted from the transmitting antenna # 1 cannot be received. In this case, the receiving side can determine that the signal transmitted from the transmitting antenna # 1 has not been received by setting an appropriate threshold value based on the transmitting antenna validity determination. As a result, the error correction decoding process is performed after the likelihood information of the encoded sequence of the high priority data for the transmission antenna # 1 is set to zero. That is, the decoding process is performed using only the likelihood information of the encoded sequence of the high priority data for the transmission antenna # 2. For this reason, the coding gain of the error correction code for the high priority data is a coding gain of a coding rate of 1/2. The same applies to the case where the signal transmitted from the transmitting antenna # 2 cannot be received.

  As described above, in the present embodiment, a transmission antenna validity determination unit is inserted into the reception device of the wireless communication device described in Embodiment 1, and signals (high priority data) transmitted from each transmission antenna are received. It is determined whether or not the signal has been received at a level exceeding the specified threshold value. If the signal cannot be received at a level exceeding the specified threshold value, the likelihood information is set to zero and the decoding process is performed. Thereby, likelihood information with low reliability can be discarded, and degradation of decoding performance can be prevented. That is, the decoding performance can be improved as compared with the receiving apparatus described in the first embodiment.

Embodiment 3 FIG.
In the radio communication apparatuses according to the first and second embodiments, low priority data cannot be decoded on the receiving side unless signals transmitted from all transmission antennas can be received. This is because, after performing one error correction encoding process on the low priority data, a division process for distributing the encoded sequence of the low priority data to each transmission antenna is performed. On the other hand, in the radio communication apparatus according to the present embodiment, a signal transmitted from a certain transmission antenna is configured by performing individual error correction coding processing for each transmission antenna for low priority data. If the signal transmitted from the transmission antenna cannot be decoded, the signals transmitted from other transmission antennas can be decoded by individual error correction decoding processing.

5A and 5B are diagrams illustrating a configuration example of the wireless communication apparatus according to the third embodiment, and illustrate a modification of the wireless communication apparatus (transmitting apparatus, receiving apparatus) according to the first embodiment. . Specifically, a configuration example in the case of performing individual error correction coding processing for each transmission antenna on low priority data is shown. That is, the transmission apparatus illustrated in FIG. 5A includes the error correction coding unit 102, the interleaver 122, and the division unit 130 of the transmission apparatus described in Embodiment 1 (see FIG. 1-1). A plurality of error correction coding units 511 and a plurality of interleavers 521 are replaced. First, the division unit 501 divides the low-priority data according to the number of transmission antennas N _t , and divides it into each divided series. On the other hand, the plurality of error correction encoding units 511 and the plurality of interleavers 521 perform error correction encoding and interleaving, respectively. Each series after interleaving is input to the corresponding symbol mapping section 141.

  The receiving apparatus illustrated in FIG. 5-2 includes an error correction decoding unit 202 and a deinterleaver 222 of the receiving apparatus described in Embodiment 1 (see FIG. 1-2), a rearrangement unit 601, and a plurality of error corrections. It is replaced with a decoding unit 611 and a plurality of deinterleavers 621, and the original low-priority data is obtained by executing a process reverse to the process performed on the transmission device side for the received signal of the low-priority data. To restore. FIG. 6 is a diagram illustrating another configuration example of the wireless communication apparatus according to the third embodiment, and illustrates a modification of the wireless communication measure (receiving apparatus) according to the second embodiment. That is, the receiving apparatus shown in FIG. 6 includes an error correction decoding unit 202 and a deinterleaver 222 of the receiving apparatus described in Embodiment 2 (see FIG. 4), a rearrangement unit 701, and a plurality of error correction decodings. 711 and a plurality of deinterleavers 721, and the same low-priority data is obtained by executing the same processing as the reception apparatus shown in FIG. To restore. Note that the processing for high priority data is as described in the second embodiment. Further, the configuration of the transmission apparatus with respect to the reception apparatus in FIG. 6 is the same as that of the transmission apparatus shown in FIG.

  As described above, in the wireless communication measure of the present embodiment, individual error correction coding processing is performed for each transmission antenna with respect to low priority data. As a result, even when a signal transmitted from a certain transmission antenna cannot be received, the reception side (receiving device) can decode the received signal if the signal transmitted from another transmission antenna can be received. can do. That is, when a signal transmitted from a certain transmission antenna cannot be received, communication is disabled in the first and second embodiments, whereas in this embodiment, the communication state is maintained for low priority data. be able to.

Embodiment 4 FIG.
As described above, in the wireless communication apparatus according to the first embodiment, check bits for high priority data are distributed to each transmission antenna. At this time, check bits are distributed so that error correction decoding can be performed in units of transmission antennas by combining with information bits copied for each transmission antenna. On the other hand, in the present embodiment, a configuration is shown in which the processing is easier than in the first embodiment, and the same data, that is, the copied check bit is allocated to each transmission antenna with respect to the check bit for high priority data. .

  FIG. 7-1 is a diagram illustrating a configuration example of a transmission device included in the wireless communication device of the fourth embodiment, and FIG. 7-2 is a diagram of a reception device included in the wireless communication device of the fourth embodiment. It is a figure which shows the example of a structure. The difference from the wireless communication apparatus of the first embodiment is that, in the transmission apparatus, the rearrangement unit 112 of the transmission apparatus (see FIG. 1-1) described in the first embodiment is replaced with a copy unit 311. In the transmission apparatus according to the present embodiment, copy processing is also performed for check bits of high priority data. In the receiving apparatus, the rearrangement unit 212 of the receiving apparatus (see FIG. 1-2) described in Embodiment 1 is replaced with a likelihood combining unit 312, and likelihood information for check bits of high priority data. Also synthesize. That is, in the transmission apparatus, the check bits are copied and distributed for each transmission antenna in the same manner as the information bits of the high priority data. In accordance with this, since the same data is transmitted from each transmitting antenna in the same manner as the information bits of the high priority data, the likelihood information of the check bits is synthesized by the likelihood synthesizer.

  As described above, in the radio communication apparatus according to the present embodiment, for the high-priority data, the check bit and the check bit are copied and transmitted for each transmission antenna, so the radio communication apparatus according to the first embodiment. Compared with, the processing can be simplified.

  As described above, the transmission device, the reception device, and the wireless communication device according to the present invention are useful when communication is performed using a plurality of antennas, and in particular, a plurality of types of data having different priorities are transmitted and received in parallel. Suitable for wireless communication.

101, 102, 511 Error correction encoding unit 111, 311 Copy unit 112, 212, 601, 701 Rearrangement unit 121, 122, 301, 521 Interleaver 130, 501 Dividing unit 141 Symbol mapping unit 151 Transmitting antenna 201, 202, 611, 711 Error correction decoding unit 211, 312 Likelihood combining unit 221, 222, 621, 721 Deinterleaver 231 Demapping unit 240 MIMO equalizing unit 251 Receiving antenna 302, 303 Recursive systematic convolutional coding unit 421 Transmitting antenna Validity judgment part

Claims (12)

A transmission device that transmits high priority data and low priority data using a plurality of transmission antennas,
As a configuration for generating a transmission sequence corresponding to the high priority data,
Error correction encoding means for generating an information bit sequence, a first check bit sequence, and a second check bit sequence by error correction encoding the high priority data;
And copying means for generating the plurality of transmit antennas and the same number of information bit sequence by copying the information bit sequence,
Reordering means for distributing each bit of the first check bit sequence and each bit of the second check bit sequence to each of the plurality of transmission antennas to generate the same number of rearranged bit sequences as the plurality of transmission antennas. When,
High priority for generating a transmission sequence of high priority data for each transmission antenna by combining any one of a plurality of rearranged bit sequences generated by the rearranging unit and the information bit sequence output from the copying unit A transmission sequence generation means;
A transmission device comprising: The high-priority transmission sequence generation unit combines any one of the plurality of rearranged bit sequences with the information bit sequence output from the copy unit, and further performs interleaving to generate the transmission sequence The transmission apparatus according to claim 1, wherein: Error correction encoding means for error correcting encoding the low priority data;
Low-priority transmission sequence generation means for generating low-priority data transmission sequences by dividing the low-priority data after error correction coding so as to have the same number as the transmission antennas;
Transmission symbol data generating means for generating transmission symbol data by mapping the transmission sequence of the high priority data and the transmission sequence of the low priority data to the same symbol;
The transmission device according to claim 1, further comprising: Dividing means for dividing the low priority data so as to have the same number as the transmission antennas;
Low-priority transmission sequence generation means for individually generating error-correction coding for each of the divided low-priority data and generating a transmission sequence of low-priority data;
Transmission symbol data generating means for generating transmission symbol data by mapping the transmission sequence of the high priority data and the transmission sequence of the low priority data to the same symbol;
The transmission device according to claim 1, further comprising: A transmission device that transmits high priority data and low priority data using a plurality of transmission antennas,
As a configuration for generating a transmission sequence corresponding to the high priority data,
Error correction encoding means for error correction encoding the high priority data;
First copy means for copying the information bit sequence of the high priority data after error correction coding and generating the same number of information bit sequences as the plurality of transmission antennas;
A second copy means for copying a check bit sequence of the high priority data after error correction coding to generate the same number of check bit sequences as the plurality of transmission antennas;
A high-priority transmission sequence that generates a transmission sequence of high-priority data for each transmission antenna by combining the information bit sequence output from the first copying unit and the check bit sequence output from the second copying unit Generating means;
A transmission device comprising: A reception device that receives a signal transmitted from the transmission device according to any one of claims 1 to 4,
Demapping means for calculating likelihood information of each bit transmitted from each transmission antenna by performing demapping processing on symbol data for each transmission antenna;
Of the calculated likelihood information, likelihood information corresponding to information bit sequences of high priority data, likelihood combining means for combining likelihood information of the same information bits,
Of the calculated likelihood information, the likelihood information corresponding to the check bit sequence of the high priority data is combined, and the combined likelihood information is subjected to a process reverse to that of the rearranging means. Sorting means for sorting and
Error correction decoding means for performing error correction decoding of high priority data based on the combined likelihood information and the rearranged likelihood information;
A receiving apparatus comprising: Determination means for calculating a cumulative value for each transmission antenna of each piece of likelihood information corresponding to high priority data among the calculated likelihood information and determining whether or not each of the calculated cumulative values has reached a predetermined value ,
Further comprising
The likelihood combining means and the rearranging means treat the likelihood information of each bit transmitted from the transmission antenna corresponding to the cumulative value determined to have reached the predetermined value by the determination means as a processing target. The receiving device according to claim 6.   The determination means outputs the likelihood information of each bit transmitted from the transmission antenna corresponding to the accumulated value determined to have reached the predetermined value as it is to the likelihood combining means or the rearranging means, The likelihood information of each bit transmitted from the transmission antenna corresponding to the cumulative value determined not to reach the predetermined value is set to zero and output to the likelihood combining means or the rearranging means. The receiving device according to claim 7, characterized in that: Of the calculated likelihood information, error correction decoding means for performing error correction decoding of low priority data based on likelihood information corresponding to low priority data;
The receiving apparatus according to claim 6, 7 or 8, further comprising: A receiving device that receives a signal transmitted from the transmitting device according to claim 5,
Demapping means for calculating likelihood information of each bit transmitted from each transmission antenna by performing demapping processing on symbol data for each transmission antenna;
Of the calculated likelihood information, for likelihood information corresponding to an information bit sequence of high priority data, first likelihood combining means for combining likelihood information of the same information bits;
Of the calculated likelihood information, second likelihood combining means for combining likelihood information of the same information bits with respect to likelihood information corresponding to an information bit sequence of low priority data;
Error correction decoding of high priority data is performed based on the likelihood information after being synthesized by the first likelihood synthesis means and the likelihood information after being synthesized by the second likelihood synthesis means. Error correction decoding means;
A receiving apparatus comprising: The transmission device according to any one of claims 1 to 4,
The receiving device according to any one of claims 6 to 9,
A wireless communication apparatus comprising: A wireless communication method in a wireless communication system for transmitting and receiving high priority data and low priority data using a plurality of antennas,
As processing executed by the wireless communication device on the transmission side,
An error correction encoding step for generating an information bit sequence, a first check bit sequence, and a second check bit sequence by error correction encoding the high priority data;
And a copy step of the copy information bit sequence, and generates as many information bit sequence of transmission antennas,
The first check bit sequence and the second check bit sequence are assigned to each of the plurality of transmission antennas to generate the same number of rearranged bit sequences as the plurality of transmission antennas . A sorting step;
A high-priority transmission sequence generation step for generating a transmission sequence of high-priority data by combining any one of the generated plurality of rearranged bit sequences and the information bit sequence;
A mapping step of mapping the transmission sequence to generate symbol data for each transmission antenna;
Including
As processing executed by the wireless communication device on the receiving side,
A demapping step of calculating likelihood information of each bit transmitted from each transmission antenna by performing demapping processing on the symbol data for each transmission antenna;
Of the calculated likelihood information, for likelihood information corresponding to information bit sequences of high priority data, likelihood combining step for combining likelihood information of the same information bits,
Of the calculated likelihood information, the likelihood information corresponding to the check bit sequence of the high priority data is combined, and further, a process reverse to the first sorting step is performed on the combined likelihood information. A second reordering step to perform reordering;
An error correction decoding step for performing error correction decoding of high priority data based on the combined likelihood information and the rearranged likelihood information;
A wireless communication method comprising:

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