JP2002368627A - Error correction controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operating method and a control method that can enhance decoding characteristic in turbo coding to facilitate the system design. SOLUTION: A Reed-Solomon(RS) code is used for an external code, a Turbo code is used for an internal code as an error correction code for a radio communication unit, number of repetitive arithmetic operation times in the inside of a Turbo coding decoder is varied on the basis of a result of error detection of an RS code decoder, an RS code encoder output is rearranged in units of a plurality of bits and the length of a processed frame is varied to provide error correction control, depending on the state of transmission line. Furthermore, a dynamic range suppressor is used for the Turbo code decoder so as to make the decoding performance enhance itself.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an invention for improving the decoding accuracy of a digital communication system using a Turbo code, and to provide a control means for dynamically changing various parameters of the Turbo code according to the state of a transmission path. By doing so, it is an invention that facilitates system design and enables reduction of current consumption when transmission conditions are good. It is useful as an error correction control technique for digital communication systems such as low power wireless, mobile phone, satellite communication, and broadcasting.

[0002]

2. Description of the Related Art FIG. 1 is a schematic diagram of a Turbo code decoder. FIG. 2 is a block diagram of a conventional transmission / reception system using only a Turbo code encoder and a decoder as an error correction code. The figure shows that noise is superimposed on the transmission path.

[0003]

[Description of the operation of the prior art] Conventional Turbo shown in FIG.
The code decoder has a plurality of decoding stages, and each stage uses signal estimation information from another stage. At this time, when the frame length is long or the number of stages is large, the estimated value becomes too large, and overflow occurs in a finite word length digital signal processor or the like.
Estimation accuracy tends to be degraded due to loss of digits. Here, information bits are estimated using information bits' noise 'with noise, parity bits 0' for stage 0, and estimation information output from the deinterleaver 24 of stage 1. The estimation information is transferred to the stage 1 MAP decoder 123 through the interleaver 21. Similarly, in stage 1, the information bit '
MAP using parity bit 1 ', stage 0 estimation information
The decoder 1 estimates information bits. While exchanging the estimation information with other stages, the estimation accuracy is improved by repeatedly operating the MAP decoder.
The arithmetic processing of the MAP decoder is enormous, and excessive repetitive operations waste current consumption. After a certain number of iterative decodings, the information bit estimation values from each stage are added at 25 and a threshold decision is made at 26 to obtain the final output of decoded bits. Fig. 2 shows a transmission / reception system using only a conventional Turbo code as an error correction code.

[0004]

[Problems to be Solved by the Invention] 1. Improvement of correction capability of Turbo code. 2. Since the Turbo code encoder has a recursive structure, the distance between codes is greatly affected by the value of input bits, and the lower limit is not guaranteed. For this reason, the code sequence after encoding is sometimes similar for different input bit sequences, and in the case of a transmission line with much noise, it is difficult for the Turbo code decoder to estimate the original input bits, resulting in error correction. Performance may be significantly reduced. Particularly in the case of periodic noise, the situation may not be improved even if retransmission is repeated. 3. The Turbo code decoder can improve the decoding accuracy by repeating the decoding process, but the arithmetic processing of the MAP decoder is enormous, and the current consumption may increase if the number of repetitions is increased . 4. For a convolutional code having a recursive structure, the longer the processing frame length, the better the decoding characteristics. However, if the processing frame length is designed to be long in accordance with the worst case, there is a trade-off factor in communication system design that the time delay between encoding and decoding increases and communication responsiveness deteriorates.

[0005]

[Object of the Invention] The present invention is based on Turbo as shown in FIGS.
Code encoder, to a communication system using a decoder, a new encoding, decoding method, pre-processing, by adding post-processing, solve the above problems 1, 2, 3, 4 to improve the error correction capability. It is a main object of the present invention, and further an object of the present invention is to provide an operation and control method suitable for this device.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the following measures are taken in each claim of the present invention. First, in claim 1, the transmitter is a coding encoder having a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame, the purpose is to perform grouping in appropriate plural bit units, and perform rearrangement of the groups. Group interleaver used in the configuration, comprising a coding device using a Turbo code encoder, the receiver, when decoding, suppresses the numerical dynamic range of the decoding evaluation information that is mutually exchanged between the MAP decoders contained therein A Turbo code decoder corresponding to the Turbo code encoder used in the encoding device, before reordering the group order rearranged by the group interleaver of the encoding device. Degroup interleaver used for the purpose of rearranging in the order of It has a configuration comprising a decoding apparatus using a code decoder having a function of detecting the presence or absence of uncorrectable error symbols in the processing frame is. The error correction control device is used in each of the transmitter and the receiver, and provides an appropriate operation control to the encoding device and the decoding device. The Turbo code decoder according to claim 2 includes a plurality of M-codes used in the Turbo code decoder according to claim 1.
The configuration includes a dynamic range suppressor used to suppress a numerical dynamic range of decoding evaluation information exchanged between AP decoders. The encoding apparatus according to claim 3 divides input frame bits for the Turbo code encoder according to claim 1 into groups of appropriate plural bits, and uses a group interleaver used for the purpose of rearranging the groups. The configuration was provided. Then, the decoding device of claim 4 provides the decoding device of claim 3
The output frame sequence of the Turbo code decoder of the communication device facing the transmitter having the encoding device equipped with the group interleaver described above, the group before being rearranged by the group interleaver, and the degroup used for rearrangement. The configuration was such that an interleaver was provided. The encoding apparatus according to a fifth aspect is configured to include a coding encoder that is disposed before the group interleaver according to the third aspect and has a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame. The decoding device according to claim 6 is arranged at a stage subsequent to the degroup interleaver according to claim 3, and has a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame. ). An error correction control device according to a seventh aspect of the present invention provides an error correction control device that has a function for detecting the presence or absence of an uncorrectable error symbol in a processing frame provided in the decoding device according to the sixth aspect. Is detected, re-decoding processing is requested to the Turbo code decoder, the number of times of repeated decoding inside the Turbo code decoder is set to be increased, and control means for performing decoding processing is provided. The error control device according to claim 8 is the error control device according to claim 7.
After the re-decoding by the rbo code decoder, in the processing by the coding decoder having the function of detecting the presence or absence of an uncorrectable error symbol in the processing frame, if the uncorrectable error symbol is detected again, And a control means for notifying the coding apparatus of the apparatus and requesting retransmission. The error correction control device according to claim 9 responds to a retransmission request issued by the error correction control device according to claim 8 by:
At the opposing transmitter, grouping and group-by-group rearrangement by the group interleaver, Turbo
In the decoding device that performed the encoding process by the code encoder and further issued the retransmission request, the decoding process by the Turbo code decoder, the rearrangement process by the degroup interleaver, and the presence or absence of an uncorrectable error symbol in the processing frame were detected. Control means for detecting a presence or absence of an uncorrectable error symbol in a processing frame by a coding decoder having a function of performing, and again repeating a series of processes leading to a retransmission request to a coding device of an opposite transmitter. did. The transmitter and the receiver according to claim 1, wherein the error correction control device according to claim 10 is such that the time when the number of repetitions exceeds a certain number continues or the time when the number of error bits exceeds a certain number continues. When the time during which it is determined that the signal propagation state is not preferable continues, a configuration is provided in which control means for increasing the processing frame length is provided.
The error correction control device according to claim 11, wherein the time during which the number of repetitions is equal to or less than a certain number continues, or the time when the number of error bits is equal to or less than a certain number continues. When the time when it is determined that the signal propagation situation is preferable continues, the control means is provided for returning the processing frame length changed in claim 10 to the original.
A coding apparatus according to a twelfth aspect has a function for detecting the presence or absence of an uncorrectable error symbol in a processing frame that can handle the processing frame length changed in the tenth or eleventh aspect. The configuration includes an encoder, a group interleaver, and a Turbo code encoder. The decoding apparatus according to claim 13 has a function for detecting the presence or absence of an uncorrectable error symbol in a processing frame that can correspond to the processing frame length changed in claim 10 or 11. A decoder, claim 12.
A degroup interleaver corresponding to the group interleaver described above, and a Turbo code decoder corresponding to the Turbo code encoder according to claim 12 are provided. Note that a code having a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame is an RS (Reed-Solomon) code used as a concatenated code or a BCH (Bose-Chau
dhuri-Hocquenghem code or CRC (Cyclic Redun)
dancy Check) is a code having a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame such as a code, and is hereinafter simply abbreviated as “RS code or the like”. Next, how each of the above-mentioned means taken in the present invention solves the above-mentioned respective task items will be described. First, item 1
Solves the problem by using a dynamic range suppressor to suppress overflow and dropout of a calculation result when acquiring estimation information of a signal from another decoding stage in a MAP decoder. Regarding the solution of the problem item 2, the error correction control device according to the present invention, prior to the Turbo code encoder in the encoding device, the input information bits, previously encoded with an RS code or the like, after that, Turbo code To change the bit arrangement after encoding, the data is grouped in an appropriate number of bits, processed by a group interleaver used for the purpose of rearranging between groups, and then subjected to Turbo code encoding and transmitted. After encoding by the encoding device,
Transmitted, in the transmission path, after decoding the encoded signal with noise superimposed in the Turbo code decoder in the decoding device of the opposing receiver, the group rearranged by the group interleaver used in the encoding device After processing by a degroup interleaver used for the purpose of restoring the arrangement, the presence or absence of an error symbol in the processing frame is determined by a decoder such as an RS code. Request retransmission from the encoder of the transmitter. At the time of retransmission, the encoding apparatus solves the problem by rearranging the encoded bits, such as RS codes, to be transmitted by the group interleaver, and then performing Turbo code encoding and transmitting. Next, task item 3
In the first, the number of times of iterative decoding of the Turbo code decoder is set to a small number, and after decoding processing is performed by the RS etc. code decoder, when an uncorrectable error symbol is detected, again, the Turbo code is repeatedly decoded. And the problem is solved by the Turbo code decoder performing iterative decoding again. Finally, in the problem item 4, instead of always using a long processing frame based on the worst case assumption, a short processing frame with good communication responsiveness is usually used, and the average of the number of retransmissions exceeds a preset number. Only when this occurs, the setting is changed to increase the processing frame length. In addition, when the error-free state or the state in which no retransmission request occurs for a certain period of time continues for a long frame length, the problem is solved by using a control method for shortening the processing frame length again in order to improve communication responsiveness.

[0007]

With respect to item 1, by taking the above measures, the Eb / N0 versus bit error rate characteristics are improved. An encoder having a recursive structure cannot guarantee the lower limit of the inter-code distance, and sometimes the decoding error may increase significantly depending on whether the code arrangement after encoding is similar. In this case, using the solution to the above-mentioned problem item 2, the presence or absence of an error is determined on the decoding device side, a retransmission request is made to the transmission side, and further, not only the simple retransmission is performed on the transmission side,
The group interleaver changes the grouping of bits in a frame and the arrangement of the groups, thereby improving Tu
By changing the code arrangement of the rbo code, it is possible to improve the transmission accuracy not only for random noise but also for periodic noise. In the solving means for the problem item 3, instead of setting a fixed number of times of repeated decoding according to the worst case from the beginning, dynamically determining the number of times of repeated decoding with reference to a decoding result of a decoder such as RS. Accordingly, when the condition of the transmission path is favorable, the current consumption can be reduced. Also, at the time of system operation, a function of dynamically changing the processing frame length in accordance with the state of the transmission line according to the frequency of retransmission requests makes it easy to determine the processing frame length at the time of system design.

[0008]

[Embodiment 1] FIG. 3 is a diagram of the entire encoding apparatus of the first embodiment, FIG. 4 is a functional diagram of the group interleaver, FIG. 5 is a diagram of the entire decoding apparatus of the first embodiment, and FIG.
Fig. 7 is a detailed diagram of the Turbo code decoding stage, Fig. 8 is a functional diagram of the degroup interleaver,
9 is an operation flow in the decoding output permission device, FIG. 10 is a wireless communication device using the encoding device and the decoding device of the present invention, and FIG.
11 shows a retransmission request transmission procedure. First, an encoding device mounted on the transmitter will be described. The entire encoding apparatus according to the first embodiment shown in FIG. 3 will be described. The information bits are input and are encoded by an encoder 41 such as an RS code. Here, the RS code or the like is a BCH code capable of determining the presence or absence of an error symbol in a processing frame, or Reed-So
Refers to error correction code such as lomon (RS) code or error detection code such as CRC. Next, in group interleaver 42, RS
The code bits of the output frame buffer of the encoder such as codes are divided into groups by an appropriate number of bits, and the groups are rearranged. For example, when the frame bit length is 1000 bits, the data is classified into 10 groups of group 1 to group 10 in 100-bit units from the first bit, and the groups are rearranged such as group 4, group 10, group 1,. After that, the input to the Turbo code encoder 43 is used to change the code arrangement of Turbo code encoder output bits. The number of bits for grouping and the order of rearrangement must be determined in advance,
The order of rearrangement is determined using the counter value of the retransmission request counter 44 as a key. Thereafter, encoding processing is performed by a Turbo code encoder, and encoded bits are output. Figure 4
A functional diagram of the group interleaver of FIG. As described above, the group interleaver divides the code bits of the output frame buffer 50 of the encoder such as the RS code into groups by an appropriate number of bits, and rearranges the groups.
In the present embodiment, the order is determined by the selector 51 using the retransmission request counter value as a key, and the sorted group is transferred to the group interleaver output buffer 52. I have.
The contents of the completed group interleaver output buffer are transferred to the Turbo code encoder. Next, a decoding device mounted on the receiver will be described. Figure 5
Will be described with reference to FIG. The coded bits transmitted from the coding device of the opposite transmitter are converted into an analog signal on which noise is superimposed on the transmission path by the A / D conversion device 6.
1 and is converted to soft-decision data here and input to the Turbo code decoder 62. After the soft decision data is decoded by the Turbo code decoder, the degroup interleaver 63
Is forwarded to The degroup interleaver is used to restore the groups rearranged by the group interleaver of the opposing transmitter to the original group. The order of rearrangement is determined by keying the retransmission counter value output from the decoding output permitting device. . Thereafter, the data is transferred to the decoder 64 such as the RS code, decoded, and output as the final decoded bit only when the output permission of the decoding output permission device is given. Output permission is determined based on a decoding status signal output from a decoder such as an RS code. The decoding status signal is obtained simultaneously with the decoding operation of the decoder such as the RS code, and indicates the presence or absence of an uncorrectable error symbol in the decoded frame. When the output permission is not obtained, the decoding output permission apparatus first requests the Turbo code decoder to perform the iterative decoding process of the same frame. When the upper limit of the number of times of the iterative decoding processing is reached, and after the decoder processing such as RS, there remains no uncorrectable symbol, the retransmission request counter is incremented, and at the same time, a retransmission request is issued. As long as the uncorrectable symbols remain, the retransmission is repeated a predetermined number of times, and when the number reaches the upper limit, decoded bits containing errors are output. The entire Turbo code decoder in FIG. 6 will be described. The Turbo code decoder has a plurality of decoding stages 70, 71, 72, 73 according to the number of interleavers used in the encoder, and performs estimation decoding by repeatedly decoding while exchanging estimation information between the decoding stages. Improve. The present invention is characterized in that a repetitive decoding request is obtained from the outside, thereby increasing the number of times of repetitive decoding. Note that the information bit 'and the parity bit 0' indicate that the noise is superimposed on the original information bit and the parity bit 0 in the transmission path, and is A / D-converted soft decision data. A detailed diagram of the Turbo code decoding stage in FIG. 7 will be described. 7 shows details of a decode stage in FIG. This figure illustrates the k-th stage. A feature of the present invention is that estimation information provided from other decoding stages is input once to the dynamic range suppressor k 81,
After the dynamic range is suppressed, it is processed by the interleaver k82. A dynamic range suppressor is simply a function that does not actually have a dynamic range suppression function.
It is effective to simply multiply by a positive number smaller than 1 and reduce the absolute value of the estimated information value of the other stage. Other operations are the same as those of the conventional Turbo code decoder. Until the set upper limit of the number of times of repeated decoding is reached, the estimation information output from the deinterleaver-k 84 is transferred by the switch 85 to the dynamic range suppressor of another stage. When the number of times of repetitive decoding reaches the upper limit, the switch 85 is switched and transferred to the adder shown in FIGS. The degroup interleaver function diagram of FIG. 8 will be described. In the Turbo code output frame buffer 90, the group sequence rearranged by the group interleaver of the encoding device of the opposing transmitter is returned to the original sequence by the selector 91 with the retransmission request counter value as a key, and the degroup interleaver output frame is returned. Transfer to the buffer 92. Again, the retransmission request counter output value and 90,9
The order of the two frame buffers 2 must be determined in advance. An operation flow in the decryption output permission device of FIG. 9 will be described. First, a decoding status is obtained at 100 from a decoder such as an RS code, and it is checked whether or not there is an error-correctable symbol in the frame.If there is no error-correctable symbol, the decoding bit is set at 110. Is output. If there is an error, at 103, a counter TURBO_ITER indicating the number of times of repeated decoding of the Turbo code decoder is incremented, and at 104, it is determined whether or not the value is less than MAXITER which indicates a preset upper limit of the number of times of repeated Turbo code decoding. If the conditions are satisfied, clear TURBO_ITER to 0 at 108,
At 109, a decoding process is requested to the Turbo code decoder. It is efficient that the decoding by the RS code or the like and the determination by the decoding output permitting device are performed for each repetition decoding unit that has been collected to some extent. For example, when the Turbo code decoder has completed the iterative decoding process five times, it performs decoding such as RS code,
A decision will be made. If the determination device makes three determinations, it means that the actual Turbo code decoder has performed 15 repetitive decodings. Next, TURBO_ITER
ARQ_COUN indicating the number of retransmissions at 105 if MAXITER or more
The TER is incremented, and it is determined at 106 whether or not the number is less than a preset maximum number of retransmissions MAXARQ. If the conditions are satisfied, a retransmission request is issued at 107. If the condition is not satisfied, ARQ_COUNTER is cleared to 0 at 111 and a decoded bit including an uncorrectable symbol is output at 110. Fig. 10
Is a wireless communication device using the encoding device and the decoding device of the present invention, and it is possible to transmit information between each device by using a plurality of wireless communication devices of the present configuration. In the retransmission, it is necessary to notify the retransmission request originated by the decoding device in the receiver to the encoding device of the opposite transmitter by any method. In the present invention, it is shown that a retransmission request in the decoding device 127 is processed in the protocol processing device 124, and a frame with a retransmission request flag set is generated and transmitted. Figure 11 shows two wireless communication devices facing each other.
A shows a retransmission procedure in a wireless communication device B (hereinafter abbreviated as A or B). 9 illustrates a case where a retransmission request is issued in the decoding device B. The “retransmission request from the opposing receiver” in FIG. 3 is a retransmission request notified by the encoding device of A from B. At 140, the first transmission of A is performed to B, and a retransmission request is issued at the decoding device of B at 141, and the transmission frame for which the retransmission request flag is set by the protocol processing device of B is contained in B. Is encoded, modulated, transmitted, received at 142 and decoded at 142, and the protocol processor recognizes the retransmission request from B. Finally, the protocol processing device of A notifies its own encoding device of a retransmission request from the opposite communication device B, and retransmits after recoding.

Second Embodiment FIG. 12 shows an encoding device and a protocol processing device according to a second embodiment. The protocol processing device reads the flag indicating the operation frame length determined in the opposing communication device by the operation frame length flag identification device 160, and transmits a retransmission request transmitted from the opponent communication device and information to be encoded from now on. The data is transferred to the selector 161 together with the bit. Selector 161
Selects a long or short coding apparatus based on the flag, and transfers a retransmission request and an information input bit to the selected coding apparatus. In this embodiment, the encoding device 16 for short frames is used.
The case where 2 is selected is illustrated. The encoding apparatus 162 for short frames and the encoding apparatus 164 for long frames have the same configuration except that the frame length that can be processed is different.
Is assumed to be used. The selector 163 is
The selector 161 is used to obtain an encoded output bit from the encoding device selected. FIG. 13 illustrates a decoding device according to the second embodiment. A coded signal with noise superimposed is input,
The analog-to-digital conversion is performed by the A / D converter 170, and the soft decision data is input to the selector 171. Selector 171
When the frame immediately before the frame whose processing is to be started is decoded, the operation frame length setting device 17
Select a decoding device corresponding to the frame length determined in step 5. In the present embodiment, it is indicated that the short frame decoding device 172 has been selected. The decoding apparatus for short frames and the decoding apparatus for long frames 173 have the same configuration except that the frame length that can be processed is different.
One decoding device is used. The selector 174 selects a decoding device corresponding to the frame length determined by the active frame length setting device, outputs the decoded bits, and sends a retransmission request to the protocol processing device and the active frame length setting device 175, similarly to the selector 171. Transfer to The operation frame length setting device determines the operation frame length according to the operation flow of FIG. 14 described below, and transfers the result to the selectors 171 and 174 and the protocol processing device. FIG. 14 is an operation flow of the operation frame length setting device. First, a determination is made at 180 as to whether or not the frame is the first frame after power-on. If the condition is satisfied, ARQSUM indicating the number of retransmission requests and FR indicating the frame number are determined at 181.
Initialize AMECOUNTER to 0. Then, at 182, FRAMECOU
Increment NTER. If the condition is not satisfied, 182
Executes only the increment of FRAMECOUNTER. Next, in 183, it is confirmed whether or not there is a retransmission request transferred from the selector 174 in FIG. 13. If the condition is not satisfied, the processing ends.・ If the condition is satisfied, ARQSUM is incremented at 184 and FRAMECOUNTER> TERM is determined at 185. Where TE
RM indicates a preset retransmission count period. -When FRAMECOUNTER <= TERM, the process ends.・ If FRAMECOUNTER> TERM, ARQSUM> 186
Judge LFRAME. Here, LFRAME is a threshold value for switching to a long frame. -If ARQSUM> LFRAME, set the operation frame length identification flag in the information bits to "long" at 187, and set ARQSU at 190
Exit after clearing M and FRAMECOUNTER to 0.・ If ARQSUM <= LFRAME, ARQSUM <= SFRAME at 188
Is determined. SFRAME is a preset value for switching to a short frame, and SFRAME <LFRAME.・ If ARQSUM> SFRAME, ARQSUM, FRAMECOUNT at 190
Clear ER to 0 and end. -If ARQSUM <= SFRAME, set the operation frame identification flag in the information bits to "short" at 189, and set ARQSU at 190
Clear M and FRAMECOUNTER to 0, then exit.

[0010]

FIG. 15 shows the effect of the present invention. A comparison of the decoder with the dynamic range suppressor and the conventional method shows an improvement of about 0.5 dB. The specifications are as follows: Turbo code has generator polynomial (31,33) ₈ , punctured circuit is disabled, coding rate is 1/3, information bit length is 1000 bits / frame, decoding is repeated 15 times, dynamic range suppressor is positive. It was configured to multiply the number 0.606.
Next, the upper limit number of retransmissions 20 times Reed-Solomon code is a primitive polynomial
It has a generator polynomial composed of 1 + x ² + x ¹⁰ roots on GF (2 ¹⁰ ), 10 bits / Symbol, frame symbol length 100 symbols (information 90 symbols + parity 10 symbols), and grouping is 100 bits each They were classified into 10 groups, and rearranged for each retransmission. The characteristics of a long frame configuration of 10,000 bits / frame are also described.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a Turbo code decoder.

FIG. 2 is a transmission / reception system diagram using a Turbo code encoder / decoder.

FIG. 3 is an overall view of an encoding device according to a first embodiment.

FIG. 4 is a functional diagram of a group interleaver.

FIG. 5 is a diagram illustrating the entire decoding apparatus according to the first embodiment;

FIG. 6 is an overall diagram of a Turbo code decoder.

FIG. 7 is a detailed diagram of a Turbo code decoding stage.

FIG. 8 is a functional diagram of a degroup interleaver.

FIG. 9 is an operation flow in the decryption output permission device.

FIG. 10 is a schematic diagram of a wireless communication device using an encoding device and a decoding device of the present invention.

FIG. 11 is a diagram showing a retransmission request transmission procedure.

FIG. 12 is a schematic diagram of an encoding device according to a second embodiment.

FIG. 13 is a schematic diagram of a decoding device according to a second embodiment.

FIG. 14 is an operation flow of the operation frame length setting device.

FIG. 15 is a diagram showing an effect in the present invention.

[Explanation of symbols]

20, 23 MAP decoder, 21, 22 interleaver, 24 deinterleaver, 25 adder, 25 threshold value judging device, 30 Turbo code encoder, 31 modulator, 33 demodulator, 34 Turbo code decoder, 40 Encoding device of the first embodiment , 41 RS code encoder, 42 group interleaver, 43 Turbo code encoder, 44 retransmission request counter, 50 RS code encoder output frame buffer, 51 selector, 52 group interleaver output frame buffer, 60 decoding device of the first embodiment, 61 A / D converter, 62 Turbo code decoder, 63 degroup interleaver, 64 RS code decoder, 65 decoding output permitting device, 70, 71, 72, 73 decoding stage, 74 adder, 75 threshold value judging device, 80 decoding Stage, 81 dynamic range suppressor, 82 interleaver, 83 MAP decoder, 84 deinterleaver, 85 estimation information Switch for switching destination, 90 Turbo code output frame buffer, 91 selector, 92 degroup interleaver output frame buffer, 120 antenna, 121 isolator, 122 receiver, 123 transmitter, 124 protocol processor, 125 receive amplifier, 126 Demodulator, 127 Decoder, 128 Transmit Amplifier, 129 Modulator, 130 Encoder, 160 Operation Frame Length Judgment Device, 161, 163 Selector, 162 Short Frame Encoding Device, 164 Long Frame Encoding Device, 170 A / D converter, 171, 174 selector, 172 Short frame compatible decoder, 173 Long frame compatible decoder, 175 Operation frame length setting device,

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04L 1/00 H04L 1/00 E

Claims (13)

[Claims] An encoding encoder having a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame, a group interleaver used to perform grouping in units of a plurality of appropriate bits and perform rearrangement of groups. ,
A transmitter including an encoding device using a Turbo code encoder, including a dynamic range suppressor used to suppress a numerical dynamic range of decoding evaluation information exchanged between MAP decoders included therein during decoding. A Turbo code decoder corresponding to the Turbo code encoder used in the encoding device, and a data used for rearranging the group order rearranged by the group interleaver of the encoding device to the order before the rearrangement. A receiver comprising a group interleaver and a decoding device using a coding decoder having a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame used in the coding device. An error correction control device used in each of the transmitter and the receiver to provide appropriate operation control to the encoding device and the decoding device. 2. A Turbo code decoder according to claim 1, further comprising a dynamic range suppressor used to suppress a numerical dynamic range of decoding evaluation information exchanged between a plurality of MAP decoders. Characterized Turbo code decoder. 3. A group interleaver used for the purpose of grouping input frame bits to the Turbo code encoder according to claim 1 in units of a plurality of appropriate bits and performing rearrangement between groups. Encoding device. 4. A communication device which is opposite to a transmitter having an encoding device equipped with the group interleaver according to claim 3.
A decoding apparatus comprising: a group before reordering an output frame sequence of a Turbo code decoder by the group interleaver; and a degroup interleaver used for reordering. 5. An encoding apparatus comprising a coding encoder disposed before the group interleaver according to claim 3 and having a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame. 6. A decoding device comprising a decoder for the same code, which is arranged downstream of the degroup interleaver according to claim 3 and corresponds to a coding encoder having a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame. Device. 7. When an uncorrectable error symbol is detected by a coding decoder provided in the decoding device according to claim 6 and having a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame, An error correction control device, comprising: control means for requesting a Turbo code decoder to perform re-decoding processing, increasing the number of times of repetitive decoding inside the Turbo code decoder, and performing decoding processing. 8. After re-decoding by the Turbo code decoder according to claim 7, in the processing by the code decoder having a function of detecting the presence or absence of an uncorrectable error symbol in the processing frame, the uncorrectable error symbol is again output. 8. The error correction control device according to claim 7, further comprising control means for notifying the encoding device of the opposing transmitter when retransmission is detected, and requesting retransmission. 9. In response to a retransmission request issued by the error correction control device according to claim 8, the opposing transmitter performs grouping by a group interleaver, rearrangement by group, and encoding by a Turbo code encoder. Further, in the decoding device that has issued the retransmission request, a decoding decoder having a function of decoding by a Turbo code decoder, rearranging by a degroup interleaver, and detecting the presence or absence of an uncorrectable error symbol in a processing frame. An error correction control device characterized by comprising control means for detecting a presence or absence of an uncorrectable error symbol in a processing frame, and repeating a series of processes leading again to a retransmission request to an encoding device of an opposite transmitter. . 10. The signal propagation state between a transmitter and a receiver according to claim 1, wherein a time when the number of repetitions exceeds a certain number continues or a time when the number of error bits exceeds a certain number continues. The error correction control device according to claim 9, further comprising a control unit that increases a processing frame length when a time determined to be non-existent continues. 11. It is preferable that the signal propagation state between the encoding device and the decoding device is preferable, for example, the time during which the number of repetitions becomes equal to or less than a certain number continues, or the time when the number of error bits becomes equal to or less than a certain number continues. 11. The error correction control device according to claim 10, further comprising control means for restoring the processing frame length changed in claim 10 when the determined time continues. 12. A coding encoder, a group interleaver, and a Turbo having a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame capable of responding to the processing frame length changed in claim 10 or 11. An encoding device used for the error correction control device according to claim 10 or 11, further comprising a code encoder. 13. A code decoder having a function of detecting the presence or absence of an uncorrectable error symbol in a processing frame capable of responding to the processing frame length changed in claim 10 or 11. A decoding device used in the error correction control device according to claim 10 or 11, further comprising a degroup interleaver corresponding to the group interleaver of (1), and a Turbo code decoder corresponding to the Turbo code encoder according to (12).