JP2002171298A - Radio transmitting apparatus and transmission signal mapping method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve reception performance and transmission efficiency including decoding and retransmission on the receiving side. SOLUTION: An S / P conversion unit 101a converts transmission data A from serial data to parallel data, and converts the parallel data to 16QAM mapping unit 102 as data to be mapped to high quality bits (S0, S1). Output. The S / P converter 101b converts the transmission data B from serial data to parallel data, and converts the parallel data into low quality bits (S2, S2).
The data is output to 16QAM mapping section 102 as data to be mapped to 3). 16QAM mapping unit 10
In 2, the transmission data A and B are mapped to the signal point constellation of 16QAM by Gray Cording. afterwards,
After digital modulation processing is performed on the transmission data A and B, the transmission data is transmitted to the communication partner via the antenna 105 after the data modulation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a radio transmission apparatus and a transmission signal mapping method in a digital radio communication system.

[0002]

2. Description of the Related Art In recent years, high-speed transmission has been performed in digital radio communication systems. In particular,
In the next-generation mobile communication system, it is expected that the amount of information on the downlink will far exceed the amount of information on the uplink, and therefore, high-speed transmission on the downlink is essential.

[0003] The frequency band used in a wireless communication system is limited, and if high-speed transmission is to be performed in this limited frequency band, a multi-level modulation method must be used as a modulation method. Multi-level modulation scheme, for example, BPS
In the K (Binary PSK) system, 1 bit is used for one symbol, in the QPSK (Quadrature PSK) system, 2 bits are used for one symbol, in the 8PSK (8-level PSK) system, 3 bits are used for one symbol, and 16QAM (16 Quadrature Ampl).
In the itude modulation method, 4 bits are used for one symbol,
64QAM system (64 Quadrature Amplitude Modulatio
In n), one symbol can transmit six bits at the same frequency. As described above, by increasing the number of levels of multi-level modulation, the amount of information that can be transmitted with one symbol can be increased, and high-speed transmission can be realized.

[0004]

However, when a conventional digital radio communication system uses a multi-level modulation scheme, mapping is performed for any bit without considering the quality of each bit, and all signal sequences are of the same quality. Transmitting.

For example, in a turbo encoder, it is necessary to transmit an uncoded signal sequence (systematic bits) and a coded signal sequence (parity bits).
Although the quality of the systematic bits has a greater effect on the quality of the performance of the decoding result than the quality of the parity bits, all signal sequences are transmitted with the same quality. For this reason, the quality of systematic bits may be degraded and the performance of the decoded result may be degraded.

Further, in order to reduce data delay, it is necessary to reduce the number of retransmissions when performing retransmission. For that purpose, it is necessary that data can be transmitted by one retransmission without fail so that retransmission does not occur again. However, when retransmission is performed, retransmission signals are mapped without considering the quality of each bit, and retransmission data and other data are transmitted at the same quality. Therefore, the probability of performing retransmission twice or more increases.

Further, like a report value of the line quality,
In a single data, the upper bits are mapped without considering the quality of each bit for all bits even if the error has a greater effect on the system than the lower bits. The signal sequence is transmitted with the same quality. For this reason, the quality of bits that are most affected by errors cannot be increased, and the performance of the system tends to deteriorate.

The present invention has been made in view of the above, and provides a radio transmission apparatus and a transmission signal mapping method capable of improving reception performance and transmission efficiency including decoding and retransmission on the reception side. The purpose is to:

[0009]

A radio transmitting apparatus according to the present invention comprises: a mapping means for mapping a multi-level modulation by preferentially allocating a specific signal sequence in a transmission signal to a bit having good transmission quality in the same symbol; Transmitting means for transmitting the multi-level modulated signal to a communication partner.

According to this configuration, since the specific signal sequence is transmitted with relatively high transmission quality, the specific signal sequence is received by the radio receiving device with high quality. Quality is improved.

[0011] In the wireless transmission apparatus of the present invention, the specific signal sequence may be a group consisting of upper bits of a plurality of bits, retransmission information, information of high importance, and information having a large effect on the system. Take a configuration that is at least one selected.

[0012] A radio transmitting apparatus according to the present invention includes a turbo coding means for performing turbo coding on a transmission signal, and a signal sequence (systematic bit) not coded in turbo coding for transmission quality in the same symbol. A configuration including mapping means for assigning priority to good bits for mapping of multi-level modulation and transmitting means for transmitting a multi-level modulated signal to a communication partner is adopted.

According to these configurations, since the systematic bits are transmitted with relatively high transmission quality, the systematic bits are received by the radio receiving apparatus with high quality, and the systematic bits after turbo decoding are transmitted. The reception quality is improved.

The radio transmission apparatus of the present invention employs a configuration in which Gray Cording is used in multilevel modulation in the above configuration.

According to this configuration, since the signal point arrangement is such that the average bit error rate can be reduced most, the best performance can be obtained.

[0016] A base station apparatus according to the present invention includes the above-mentioned radio transmitting apparatus. The communication terminal device of the present invention includes:
The wireless transmission device is provided. As a result, wireless communication can be performed with improved transmission efficiency and reception performance.

According to the transmission signal mapping method of the present invention, a mapping step of mapping a multi-level modulation by preferentially allocating a specific signal sequence in a transmission signal to a bit having good transmission quality in the same symbol, and performing a multi-level modulation mapping Transmitting a signal to a communication partner.

According to this method, since the specific signal sequence is transmitted with relatively high transmission quality, the specific signal sequence is received by the radio receiving apparatus with high quality. Quality is improved.

[0019] A transmission signal mapping method according to the present invention includes a turbo coding step of performing turbo coding on a transmission signal;
A mapping step of mapping systematic bits by assigning systematic bits to bits having good transmission quality in the same symbol in turbo coding to perform multi-level modulation, and a transmission step of transmitting a multi-level modulated signal to a communication partner. , Is provided.

According to this method, since the systematic bits are transmitted with a relatively high transmission quality, the systematic bits are received by the radio receiving apparatus with a high quality, and the reception after turbo decoding is performed. Quality is improved.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In multilevel modulation such as 16QAM, there is a difference in transmission quality from bit to bit. For example, the error rate for the same S / N (signal to noise) ratio differs depending on the bit position. The present inventor has found that by utilizing this fact, by assigning a specific signal sequence (data) preferentially according to the transmission quality for each bit, it is possible to improve the transmission quality and improve the reception performance on the receiving side. Was. here,
The specific signal sequence includes upper bits of a plurality of bits, retransmission information, information of high importance, information having a large effect on the system, and the like.

FIG. 1A shows 16QAM Gray Cording.
FIG. 1B is a diagram showing a signal point arrangement in FIG.
It is a figure which shows the signal point arrangement | positioning in Gray Cording of 4QAM. This Gray Coding means that even if noise or the like is superimposed and erroneously determined as a symbol next to one symbol,
Bit mapping that requires only bit errors.

In 16QAM shown in FIG.
One symbol is represented by 4 bits, and S0 to S3 from the most significant bit to the least significant bit in bit notation. In 64QAM shown in FIG. 1 (b), one symbol is represented by 6 bits, and S0 to S5 from the most significant bit to the least significant bit in bit notation.

When such bit mapping is performed, the bit error rate in the static characteristics is as shown in FIG.
In FIG. 2, it can be seen that there is no difference in error rate for each bit in QPSK, but there is a difference in error rate for each bit in 16QAM and 64QAM. For example, in 16QAM, S
0 and S1 have better quality than S2 and S3. Also, 64QA
In M, S0 and S1 have higher quality than S2 and S3,
2, S3 has better quality than S4, S5. In FIG. 2, AVE indicates the average of the error rates of all bits.

Therefore, the gist of the present invention is to use the characteristics shown in FIG. 2 to preferentially assign data that does not want an error to occur or data that is desired to be protected to bits having good transmission quality in multi-level modulation and transmit the data. The purpose is to improve the reception performance on the receiving side by increasing the quality.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. (Embodiment 1) In this embodiment, different QoS (Qu
The signal sequence A (data A) and the signal sequence B (data B), which are quality of service, are arranged at different bits in the same symbol and subjected to multi-level modulation for transmission, thereby improving transmission quality and receiving. The case where the receiving performance of the side is improved will be described. When transmitting signal sequences of different QoS, it is possible to cope with the strength of error correction or the like. However, taking into consideration that the error rate of each bit of multi-level modulation is originally different, that is, the QoS is high. By allocating data to bits having high transmission quality and performing transmission, reception performance on the receiving device side is improved, and transmission efficiency is also improved.

FIG. 3 is a block diagram showing a configuration of the radio transmission apparatus according to Embodiment 1 of the present invention. FIG.
FIG. 3 is a block diagram showing a configuration of a wireless reception device that performs wireless communication with the wireless transmission device according to Embodiment 1 of the present invention.
In the wireless transmission device shown in FIG. 3, only the transmission system is described for simplicity of description, and in the wireless reception device shown in FIG. 4, only the reception system is described for simplicity of description. Each of the wireless transmitting devices shown in FIG. 3 has a receiving system, and the wireless receiving device shown in FIG. 4 has a transmitting system.

In this embodiment, the case where two transmission data A and B are transmitted is described for the sake of simplicity. In the present invention, three or more transmission data are transmitted. The case can also be applied. Here, it is assumed that the transmission data A has a higher QoS than the transmission data B.

The radio transmitting apparatus shown in FIG. 3 includes S / P converters 101a and 101b for serially / parallel converting transmission data (hereinafter abbreviated as S / P conversion), and 16QAM for converting the S / P converted data. 16QAM mapping section 102 for mapping to 16 signal points, a modulation section 103 for digitally modulating data after 16QAM mapping, a radio transmission section 104 for performing radio transmission processing on a signal after digital modulation, and a radio transmission section 104 for performing radio transmission processing on a signal after digital modulation. And an antenna 105 for transmitting a signal.

The radio reception apparatus shown in FIG. 4 includes an antenna 201 for receiving a radio signal, a radio reception section 202 for performing radio reception processing on a received signal, and a demodulation section 203 for demodulating a signal subjected to radio reception processing. And demodulate the signal to 16QAM
A 16QAM demapping unit 204 for demapping (determining) the signal point constellation, and P / S conversion units 205a and 205b for parallel / serial conversion (hereinafter abbreviated as P / S conversion) of data at 16QAM signal points. It has.

Next, the case where the transmission signal mapping method of the present invention is performed using the radio transmission apparatus and radio reception apparatus having the above configuration will be described.

In the radio transmission apparatus shown in FIG. 3, transmission data A and B are transmitted by S / P converters 101a and 101a, 10b, respectively.
1b. The S / P converter 101a converts the transmission data A from serial data to parallel data,
This parallel data is converted into relatively high quality bits (S0,
The data is output to 16QAM mapping section 102 as data to be mapped in S1). The S / P converter 101b converts the transmission data B from serial data to parallel data, and converts this parallel data to 1 as data to be mapped to relatively low quality bits (S2, S3).
Output to 6QAM mapping section 102.

In 16QAM mapping section 102, transmission data A and B are each mapped to a signal point constellation of 16QAM by Gray.
Mapping is performed by Cording, and the respective transmission data A and B are sent to the modulation unit 103 as a signal of an in-phase component (I component) and a signal of a quadrature component (Q component).

In the modulation section 103, I of transmission data A and B
Digital modulation processing is performed on the component signal and the Q component signal. The transmission data A and B after the digital modulation are sent to the radio transmission section 104, subjected to predetermined radio transmission processing (D / A conversion, up-conversion) by the radio transmission section 104, and then transmitted to the communication partner via the antenna 105. Sent to.

In the radio receiving apparatus shown in FIG. 4, a signal transmitted from a communication partner is received by radio receiving section 202 via antenna 201. The wireless receiving unit 202 performs a predetermined wireless receiving process (down conversion,
A / D conversion), and sends the received data after the wireless reception processing to the demodulation unit 203. The demodulation section 203 performs digital demodulation processing on the received data, and then performs the I component signal and Q
The signal is sent to 16QAM demapping section 204 as a component signal.

The 16QAM demapping section 204 converts the signal point constellation of 16QAM for the received data into Gray Cordi.
ng and demapping (determination), and for each bit, P /
Output to the S converters 205a and 205b. Here, Q
Bits S0, to which data A having a high oS is assigned,
S1 is output to P / S conversion section 205a, and bits S2 and S3 to which data B having a low QoS is assigned are converted to P / S
Output to the conversion unit 205b.

The P / S converter 205a converts the parallel data for the data A into serial data and outputs the received data A. The P / S converter 205b converts the parallel data for the data B into serial data and outputs the received data B.

The data A and the data B transmitted from the radio transmitting apparatus shown in FIG. 3 to the radio receiving apparatus shown in FIG.
, And data B is transmitted using bits S2 and S3. As shown in FIG. 2, in 16QAM, S0 and S1 have a lower bit error rate than S2 and S3, so that data A is transmitted with relatively higher transmission quality. That is, the data A having a higher QoS is transmitted in a state where errors are less likely to occur. Therefore, the data A having high QoS is received by the wireless receiving device with high quality, and the receiving performance in the wireless receiving device is improved.

In this embodiment, which data has a high QoS is determined by a method such as predetermined in the system.

(Embodiment 2) In this embodiment, transmission data and retransmission data are arranged in different bits within the same symbol, multi-level modulation is performed, and transmission is performed. A description will be given of a case in which the reception performance of the device is improved.

In the retransmission, if the retransmission data is reliably received at one time, the data transmission delay is small, but if the first retransmission data is incorrect, the second retransmission data is transmitted, and the data delay wave is transmitted. Becomes large. Therefore, by assigning retransmission data to bits having higher transmission quality than ordinary new data, transmission efficiency can be increased.

FIG. 5 is a block diagram showing a configuration of a radio transmission apparatus according to Embodiment 2 of the present invention. 5, the same parts as those of FIG. 3 are denoted by the same reference numerals as those of FIG. 3, and detailed description thereof will be omitted. In the wireless transmission device shown in FIG. 5, only the transmission system is described for simplification of description, but the wireless transmission device shown in FIG. 5 has a reception system.

In this embodiment, the case where one transmission data is transmitted is described for the sake of simplicity. However, in the present invention, even when two or more transmission data are transmitted, Can be applied.

The radio transmitting apparatus shown in FIG. 5 includes a buffer 301 for storing transmission data. Buffer 301
Outputs retransmission data or transmission data to S / P conversion sections 101a and 101b in response to a retransmission request sent from a communication partner.

Next, the case where the transmission signal mapping method of the present invention is performed using the radio transmission apparatus and the radio reception apparatus having the above configuration will be described.

In the radio transmission apparatus shown in FIG. 5, transmission data is stored in buffer 301. Buffer 30
1, if there is a retransmission request, the retransmission data
Output to the P conversion unit 101a, and new transmission data
Output to P conversion section 101b.

The error correction algorithm by retransmission includes Stop and Wait ARQ, GoBack N ARQ, Sel
effective Repeat ARQ, hybrid ARQ, and the like. Therefore, the retransmission data may be the same data as the data in which an error has occurred, or may be redundant information that only increases the error correction capability, such as Type-II or Type-III of hybrid ARQ.

The S / P converter 101a converts the retransmission data from serial data to parallel data, and converts the parallel data into bits (S0, S1) of relatively high quality.
Is output to 16QAM mapping section 102 as data to be mapped to. The S / P converter 101b converts the new transmission data from serial data to parallel data, and converts the parallel data to 16Q as data to be mapped to relatively low quality bits (S2, S3).
Output to AM mapping section 102.

The 16QAM mapping section 102 maps the retransmission data and the new transmission data to the signal point constellation of 16QAM by Gray Cording, respectively. The signal of the (Q component) is sent to the modulation section 103.

In modulation section 103, digital modulation processing is performed on the I component signal and the Q component signal of the retransmission data and the new transmission data. The retransmission data and the new transmission data after the digital modulation are transmitted to the wireless transmission unit 104, and are subjected to predetermined wireless transmission processing by the wireless transmission unit 104, and then transmitted to the communication partner via the antenna 105.

The radio receiving apparatus performs digital demodulation processing after performing predetermined radio reception processing on a signal transmitted from a communication partner. After that, the signal point arrangement of 16QAM is applied to the demodulated signal for the I component signal and the Q component signal by Gray Cor.
Demapping (determining) by ding. Then, retransmission data is obtained from bits S0 and S1 to which retransmission data is allocated, and new transmission data is obtained from bits S2 and S3 to which new transmission data is allocated.

In the retransmission data and the new transmission data transmitted from the radio transmission apparatus to the radio reception apparatus shown in FIG. 5, the retransmission data is transmitted using bits S0 and S1, and the new transmission data is transmitted. It is transmitted using bits S2 and S3. As shown in FIG. 2, in 16QAM, S0 and S1 have a lower bit error rate than S2 and S3, so that retransmission data is transmitted with relatively higher transmission quality. That is, retransmission data that is relatively undesired is transmitted in a state where errors are less likely to occur. Therefore, the retransmission data is received by the wireless reception device with high quality, and the probability that the first retransmission data is correctly received increases, and the data transmission delay can be reduced.

In this embodiment, when there is no retransmission request, the new transmission data is output to S / P conversion section 101a so that the new transmission data is transmitted to all bits S0 to S0.
The transmission may be performed by assigning to S3.

It should be noted that, in the present embodiment, the pattern in which retransmission data and new transmission data are transmitted when a retransmission request is received is determined in advance by, for example, the transmission pattern between the retransmission data and the new transmission data. May be determined, and the retransmission data and the new transmission data may be transmitted according to the transmission pattern notified from the communication partner.

(Embodiment 3) In this embodiment, when transmission data such as channel quality information is composed of a plurality of bits, upper bits and lower bits are arranged in different bits within the same symbol. A case will be described in which multi-level modulation is performed and transmission is performed to improve transmission quality and improve reception performance on the receiving side.

In the line quality information and the like, if the upper bit is wrong, the influence on the system is great. For example, if the line quality is 6
Assuming that the highest quality bit is wrong for the reported value of 63 having the highest quality, 31
Become. On the other hand, even if the least significant bit is wrong, it is only 62. Therefore, the upper bits are
By allocating to bits having higher transmission quality than the lower bits, it is possible to improve the reception performance on the receiving device side.

FIG. 6 is a block diagram showing a configuration of a radio transmission apparatus according to Embodiment 3 of the present invention. 6, the same parts as those in FIG. 3 are denoted by the same reference numerals as those in FIG. 3, and detailed description thereof will be omitted. In the wireless transmission device shown in FIG. 6, only the transmission system is shown for simplicity of description, but the wireless transmission device shown in FIG. 6 has a reception system.

In the present embodiment, the case where one transmission data is transmitted is described for the sake of simplicity. However, the present invention is applicable to the case where two or more transmission data are transmitted. Can be applied.

The radio transmitting apparatus shown in FIG. 6 includes a P / S conversion section 401a for performing P / S conversion of upper bits of transmission data,
A P / S converter 401b for performing P / S conversion on lower bits of transmission data. The P / S converter 401a performs P / S conversion on the upper bits of the transmission data to perform S / P conversion.
01 / 01a, and P / S conversion section 401b performs P / S conversion on the lower bits of the transmission data and outputs the result to S / P conversion section 101b.

Next, the case where the transmission signal mapping method of the present invention is performed using the radio transmission apparatus and the radio reception apparatus having the above configuration will be described. Here, a case where 6-bit line quality information (0 to 63) is transmitted will be described.

In the radio transmission apparatus shown in FIG. 6, transmission data (channel quality information) is divided into upper 3 bits and lower 3 bits, and P / S converters 401a and 401, respectively.
1b. The P / S conversion section 401a performs P / S conversion of the upper 3 bits of data and outputs the data to the S / P conversion section 101a. The P / S converter 401b performs P / S conversion on the lower 3 bits of data and outputs the data to the S / P converter 101b.

The S / P converter 101a converts the upper 3 bits of data from serial data to parallel data, and converts the parallel data to bits (S
0, S1) as data mapped to 16QAM
Output to the mapping unit 102. S / P converter 101b
Then, the lower three bits of data are converted from serial data to parallel data, and the parallel data is output to the 16QAM mapping unit 102 as data mapped to relatively low quality bits (S2, S3).

In 16QAM mapping section 102, upper 3 bits of data and lower 3 bits of data are
The signal is mapped to the signal point constellation of 6QAM by Gray Cording, and the signal of the in-phase component (I component) and the signal of the quadrature component (Q component) of the upper 3 bits of data and the lower 3 bits of data are sent to the modulator 103.

The modulation section 103 performs digital modulation processing on the I component signal and the Q component signal of the upper 3 bits of data and the lower 3 bits of data. The upper 3 bits data and lower 3 bits data after digital modulation are
The data is transmitted to the wireless transmission unit 104, subjected to predetermined wireless transmission processing by the wireless transmission unit 104, and then transmitted to a communication partner via the antenna 105.

The radio receiver performs a digital demodulation process after performing a predetermined radio reception process on a signal transmitted from a communication partner. After that, the signal point arrangement of 16QAM is applied to the demodulated signal for the I component signal and the Q component signal by Gray Cor.
Demapping (determining) by ding. And the top three
Bits S0 and S1 to which bit data is assigned
, The lower 3 bits of data are obtained from the bits S2 and S3 to which the lower 3 bits of data are assigned. Then, 6-bit data (line quality information) is obtained from the upper 3 bits and the lower 3 bits.

As described above, the upper 3 bits of data and the lower 3 bits of data transmitted from the radio transmitting apparatus to the radio receiving apparatus shown in FIG. 6 use the upper 3 bits of data S0 and S1. And the lower three bits of data are transmitted using bits S2 and S3.
As shown in FIG. 2, S0 and S1 in 16QAM are
Since the bit error rate is lower than S2 and S3, the data of the upper 3 bits is transmitted with relatively higher transmission quality. In other words, the upper 3 bits of data that are relatively undesired and have a large effect on the system are transmitted in a less error-prone state. Therefore, the data of the upper 3 bits is received by the radio receiver with high quality, and the probability that the important line quality information is erroneously reduced is reduced. And the deterioration of the performance of the system can be reduced. That is, for example, the probability that 63 becomes 31 as the line quality information is lower than the probability that 63 becomes 62.

In this embodiment, the system determines in advance how many bits of transmission data are to be upper bits and how many bits are to be lower bits. Therefore, there is no particular limitation on the assignment of the upper bits and the lower bits as long as higher bits, which are not desired to be mistaken, are assigned to bits having higher transmission quality in multi-level modulation. Further, when the bit error rate is classified into three or more as in 64QAM, the transmission data may be divided into three or more and assigned to bits having different transmission qualities.

In the present embodiment, when the transmission data is 6
Although the case of bits is described, the present invention can be similarly applied even if the transmission data is configured with a bit number other than 6 bits.

(Embodiment 4) Conventionally, when multi-level modulation is performed on turbo-coded data, as shown in FIG. 12, the output from turbo encoder 1, ie, T0 (uncoded data, systematic bit T1 (recursive convolution-encoded data, referred to as parity bit 1), T2 (interleaved and recursive convolution-encoded data, referred to as parity bit 2) are converted by P / S converter 2 into P / S conversion, and S / P conversion of the data into four series by the S / P converter 3,
Sequence data is assigned to S0 to S3. Then, the allocated data is digitally modulated by the modulator 5 to be a transmission signal.

In this transmission signal mapping method,
The systematic bit T0 is, as shown in FIG.
All bits 0 to S3 are equally allocated. That is, bits T0 to S3 are regularly allocated to bits S0 to S3 in the order in which the data of T0 to T2 are output. FIG.
In FIG. 3, the shaded portion indicates T0 data.

In this embodiment, when the turbo code is used, the parity bits (T1 data, T2 data) and the systematic bits (T0 data) are arranged in different bits, multi-level modulated, and transmitted. A case in which the transmission quality is improved to improve the reception performance on the receiving side will be described. Here, a case where the rate of turbo coding is 1/3 will be described.

FIG. 7 is a block diagram showing a configuration of a radio transmission apparatus according to Embodiment 4 of the present invention. 7, the same parts as those in FIG. 3 are denoted by the same reference numerals as those in FIG. 3, and detailed description thereof will be omitted. FIG. 9 is a block diagram showing a configuration of a wireless receiving apparatus that performs wireless communication with a wireless transmitting apparatus according to Embodiment 4 of the present invention. 9, the same parts as those in FIG. 4 are denoted by the same reference numerals as those in FIG. 4, and detailed description thereof will be omitted.

In the radio transmission apparatus shown in FIG. 7, only the transmission system is described for simplicity of description, and in the radio reception apparatus shown in FIG. 9, only the reception system is described for simplification of the description. However, each of the wireless transmitting devices shown in FIG. 7 has a receiving system, and the wireless receiving device shown in FIG. 9 has a transmitting system.

In this embodiment, a case where one transmission data is transmitted is described for the sake of simplicity. However, in the present invention, a case where two or more transmission data are transmitted is also applicable. Can be applied.

The radio transmitting apparatus shown in FIG. 7 includes a turbo encoder 501 for performing turbo coding on transmission data, and an S / P conversion for performing S / P conversion on three outputs (T0 to T2) from the turbo encoder 501. P / S converter 503a that performs P / S conversion on data obtained by dividing outputs from S / P converters 502a to 502c for each predetermined number of bits.
To 503d.

S / P conversion section 502a converts T0 data to 3
The P / S conversion unit 5 divides three bits into one bit and one bit.
03a, and outputs one bit to the P / S converter 503b. The S / P converter 502b divides the T1 data into two bits and two bits, and divides the two bits into P / S converters 503.
b, and outputs 2 bits to the P / S converter 503c. The S / P converter 502c divides the T2 data into one bit and three bits, outputs one bit to the P / S converter 503c, and outputs three bits to the P / S converter 503d.

The turbo encoder 501 has the configuration shown in FIG. That is, turbo encoder 501 includes interleaver 5011 for interleaving transmission data, and convolutional encoder 501 for performing recursive convolutional coding on transmission data.
2 and a convolutional encoder 5013 for performing recursive convolutional encoding on the interleaved transmission data. The output from convolutional coding section 5012 is T1 (parity bit 1), and the output from convolutional coding section 5013 is T1.
2 (parity bit 2). Data (systematic bits) that is not encoded in the transmission data is T0.

In the radio receiving apparatus shown in FIG. 9, the output of 16QAM demapping section 204, that is, bits S0 to S3
And a turbo decoder 602 that performs turbo decoding using the T0 to T2 data obtained by rearrangement.

The turbo decoder 602 has the configuration shown in FIG. That is, the turbo decoder 602 includes: a decoding unit 6021 that performs decoding using the T0 data and T1 data and external information from the deinterleaver 6024; an interleaver 6022 that interleaves the output of the decoding unit 6021; A decoding unit 6023 that performs decoding using the subsequent data, T2 data, and T0 data
And a deinterleaver 6024 for deinterleaving the output of the decoding unit 6023.

Next, the case where the transmission signal mapping method of the present invention is performed using the radio transmission apparatus and radio reception apparatus having the above configuration will be described.

In the radio transmission apparatus shown in FIG. 7, transmission data is sent to turbo encoder 501 and turbo-coded. In the turbo coding, the transmission data is output as it is to be T0 data, and the convolutional coding unit 5012
Then, the transmission data is recursively convoluted and coded into T1 data. Further, after the transmission data is interleaved by the interleaver 5011, the convolutional coding unit 5013 performs recursive convolutional coding to generate T2 data.

These T0 to T2 data are represented by S
/ P converters 502a to 502c. That is, T0 data is output to S / P conversion section 502a,
One data is output to the S / P converter 502b, and the T2 data is output to the S / P converter 502c.

The S / P converter 502a converts the T0 data from serial data to parallel data, divides the parallel data into 3 bits and 1 bit, and outputs 3 bits to the P / S converter 503a. One bit is output to P / S conversion section 503b. In the S / P converter 502b,
The T1 data is converted from serial data to parallel data, the parallel data is divided into two bits and two bits, two bits are output to the P / S converter 503b, and two bits are output to the P / S converter 503c. I do. S / P converter 5
In 02c, T2 data is converted from serial data to parallel data, and this parallel data is converted into 1 bit and 3 bits.
One bit is output to the P / S converter 503c, and three bits are output to the P / S converter 503d.

Therefore, the P / S converter 503a includes:
Three bits of the T0 data are input, and the P / S converter 503
b, 1 bit of T0 data and 2 bits of T1 data are input, 2 bits of T1 data and 1 bit of T2 data are input to the P / S converter 503c, and 2 bits of T2 data are input to the P / S converter 503d. Is input with 3 bits of T2 data.

The reason why the data T0 to T2 is allocated is to map the systematic bits (T0 data) to the bits (S0, S1) of relatively high quality. Therefore, P / S conversion section 503a outputs three bits of T0 data to 16QAM mapping section 102 as data to be assigned to bit S0. The P / S conversion unit 503b calculates one bit of T0 data and two bits of T1 data.
16QA as data to assign a bit to bit S1
Output to M mapping section 102. P / S converter 503
c outputs two bits of T1 data and two bits of T2 data to 16QAM mapping section 102 as data to be allocated to bit S2. The P / S conversion unit 503d calculates T
The three bits of the two data are output to 16QAM mapping section 102 as data to be allocated to bit S3. In addition,
The bit to which the T0 to T2 data is assigned is determined in advance in the system.

In 16QAM mapping section 102, FIG.
As shown in FIG. 1, T0 is always S0 or S0 with high transmission quality.
1 (shaded portion in FIG. 11). In this way, T0 to T2 data are each set to 1
The signal is mapped to the signal point constellation of 6QAM by GrayCording, and the in-phase component (I component) signal and the quadrature component (Q component) signal of the respective T0 to T2 data are modulated by the modulation unit 103.
Send to

The modulation section 103 performs digital modulation processing on the I component signal and the Q component signal of the data T0 to T2. The data of T0 to T2 after digital modulation is
The data is transmitted to the wireless transmission unit 104, subjected to predetermined wireless transmission processing by the wireless transmission unit 104, and then transmitted to a communication partner via the antenna 105.

In the radio receiving apparatus shown in FIG. 9, digital demodulation processing is performed after a signal transmitted from a communication partner is subjected to predetermined radio reception processing. After that, the demodulated signal is
The signal point constellation of 16QAM is demapped (determined) by Gray Cording for the component signal and the Q component signal. Then, bits S0 to S3 output from 16QAM demapping section 204 are output to rearrangement conversion section 601.

In the rearrangement conversion section 601, T0 assigned to S0 to S3 according to the assignment shown in FIG.
The T2 data is rearranged and output to the turbo decoder 602 as T0 to T2 data.

In the turbo decoder 602, the decoding unit 602
1, T0 data and T1 data and deinterleaver 60
The decoding is performed using the external information (the initial value is 0) from the H.24, the interleaver 6022 interleaves the output of the decoding unit 6021, and the decoding unit 6023 converts the interleaved data, T2 data, and T0 data. And a decoding unit 6023 using a deinterleaver 6024.
Deinterleave the output of The output of the deinterleaver 6024 is used as the reliability information as the decoding unit 602.
The above processing is repeatedly performed by feeding back to 1. Thus, the received data is obtained.

Thus, T0-T transmitted from the radio transmitting apparatus shown in FIG. 7 to the radio receiving apparatus shown in FIG.
For two data, T0 data is transmitted using bits S0 and S1, T1 data is transmitted using bits S1 and S2, and T2 data is transmitted using bits S2 and S3. As shown in FIG.
Since 0 and S1 have a lower bit error rate than S2 and S3, the T0 data is transmitted with relatively higher transmission quality. That is, T0 data that is relatively error-prone is transmitted in a state that is hardly error-prone. Therefore, the T0 data is received by the wireless reception device with high quality, and the reception quality after turbo decoding is improved.

In this embodiment, if systematic bits that are not desired to be erroneously assigned are assigned to bits having high transmission quality in multi-level modulation, there is no particular limitation on which turbo-coded data is assigned to which bit. Absent.

In the present embodiment, the case where the turbo coding rate is 1/3 is described, but the present invention is similarly applied to the case where the turbo coding rate is other than 1/3. can do.

In the first to fourth embodiments, the multi-level modulation is one.
Although the case of 6QAM is described, the present invention uses 64QAM (6 bits per symbol) as multi-level modulation.
Or 256QAM (8 bits per symbol)
Similar effects can be obtained by using multi-level modulation other than 6QAM. In particular, in multi-level modulation with many multi-level numbers,
Since the bit error rate for each bit varies stepwise, the quality of the data to be transmitted can be changed stepwise.

Although the first to fourth embodiments have described the case where Gray Coding is used in multi-level modulation, the present invention is similarly applied to the case where modulation other than Gray Coding is performed in multi-level modulation. can do. However, since Gray Coding is a signal point arrangement capable of lowering the average bit error rate, Gr.
The best performance is obtained by using ay Coding.

The present invention is not limited to the first to fourth embodiments, but can be implemented with various modifications. The wireless transmission device of the present invention can be applied to a base station device or a communication terminal device in a digital wireless communication system. As a result, wireless communication can be performed with improved transmission efficiency and reception performance.

[0097]

As described above, according to the present invention, when performing multi-level modulation, information that is not desired to be erroneous, important information, or erroneous information is transmitted to the system by utilizing the superiority of the transmission quality for each bit. Since information having a large influence is allocated to bits having relatively high transmission quality and transmitted, it is possible to improve reception performance and transmission efficiency including decoding and retransmission on the receiving side.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of Gray Cording of 16QAM and 64QAM.

FIG. 2 is a diagram showing a relationship between a bit error rate and C / N.

FIG. 3 is a block diagram showing a configuration of a wireless transmission apparatus according to Embodiment 1 of the present invention.

FIG. 4 is a block diagram showing a configuration of a wireless receiving apparatus that performs wireless communication with the wireless transmitting apparatus according to Embodiment 1 of the present invention.

FIG. 5 is a block diagram showing a configuration of a wireless transmission apparatus according to Embodiment 2 of the present invention.

FIG. 6 is a block diagram showing a configuration of a radio transmission apparatus according to Embodiment 3 of the present invention.

FIG. 7 is a block diagram showing a configuration of a radio transmission apparatus according to Embodiment 4 of the present invention.

8 is a block diagram illustrating a configuration of a turbo encoder in the wireless transmission device illustrated in FIG.

FIG. 9 is a block diagram showing a configuration of a wireless receiving apparatus that performs wireless communication with a wireless transmitting apparatus according to Embodiment 4 of the present invention.

10 is a block diagram showing a configuration of a turbo decoder in the wireless reception device shown in FIG.

FIG. 11 is a diagram showing bit allocation in a transmission signal mapping method according to Embodiment 4 of the present invention.

FIG. 12 is a block diagram showing a configuration of a conventional wireless transmission device.

FIG. 13 is a diagram showing bit allocation in a conventional transmission signal mapping method.

[Explanation of symbols]

101a, 101b, 502a to 502c S / P conversion section 102 16QAM mapping section 103 Modulation section 104 Radio transmission section 105, 201 Antenna 202 Radio reception section 203 Demodulation section 204 16QAM demapping section 205a, 205b, 401a, 401b, 503a to
503d P / S conversion section 301 Buffer 501 Turbo encoder 601 Relocation conversion section 602 Turbo decoder 5011,6022 Interleaver 5012,5013 Convolutional coding section 6021,6023 Decoding section 6024 Deinterleaver

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kenichi Miyoshi 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama-shi, Kanagawa F-term in Matsushita Communication Industrial Co., Ltd. (Reference) 5K004 AA08 JA03 JD05 5K067 AA13 CC00 DD41 EE02 EE10 HH22

Claims (8)

[Claims] 1. Mapping means for mapping a multi-level modulation by preferentially assigning a specific signal sequence in a transmission signal to bits of the same symbol having good transmission quality,
A transmission unit for transmitting a multi-level modulated signal to a communication partner. 2. The specific signal sequence is at least one selected from the group consisting of upper bits in a plurality of bits, retransmission information, information of high importance, and information having a significant effect on the system. The wireless transmission device according to claim 1, wherein: 3. Turbo coding means for performing turbo coding on a transmission signal, and performing multi-level modulation mapping by assigning systematic bits to bits having good transmission quality in the same symbol in turbo coding. A wireless transmission device comprising: a mapping unit; and a transmission unit that transmits a multi-level modulated signal to a communication partner. 4. The radio transmitting apparatus according to claim 1, wherein Gray Cording is used in the multi-level modulation. 5. A base station device comprising the wireless transmission device according to claim 1. 6. A communication terminal device comprising the wireless transmission device according to any one of claims 1 to 4. 7. A mapping step in which a specific signal sequence in a transmission signal is preferentially assigned to a bit having good transmission quality in the same symbol to perform mapping of multi-level modulation,
Transmitting a multi-level modulated signal to a communication partner. 8. A turbo coding step of performing turbo coding on a transmission signal, and performing multi-level modulation mapping by assigning systematic bits to bits having good transmission quality in the same symbol in turbo coding. A transmission signal mapping method, comprising: a mapping step; and a transmission step of transmitting a multi-level modulated signal to a communication partner.