JP2008205944A - Radio signal receiver and radio signal reception method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio signal receiver and a radio signal reception method which can suppress a deterioration in correction rate of transmission errors caused by interference between received radio signals. <P>SOLUTION: The receiver 200 is provided with log-likelihood ratio processing part 253 which judges whether or not a degree of reliability of log-likelihood ratio LLR is equal to or more than a predetermined threshold and a buffer 265a which stores encoded data D1 having the log-likelihood ratio LLR judged to be less than the predetermined degree of reliability among pieces of encoded data D1 included in the received radio signal. A decoding processing part 260, when the log likelihood ratio LLR of the encoded data D1 stored in the buffer 265a is judged to be equal to or more than the predetermined degree of reliability, decodes the encoded data D1 stored in the buffer 265a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention receives a plurality of radio signals in the same frequency band, decodes encoded data included in the radio signal according to a predetermined error correction code, and encodes code based on likelihood information indicating the likelihood of the encoded data. The present invention relates to a radio signal receiving apparatus and radio signal receiving method for repeatedly decoding coded data.

  2. Description of the Related Art Recently, in a wireless communication system such as a mobile communication system, multiple input multiple output (MIMO) that improves throughput by using a large number of transceivers (antennas) that transmit and receive wireless signals in the same frequency band has been put into practical use.

  Also, in wireless communication systems, the turbo code method is widely used as an error correction code method for transmission errors that occur on the propagation path.

When MIMO and turbo coding are used in a wireless communication system, a turbo decoder is provided for each received wireless signal in a receiver (wireless signal receiver) (for example, Patent Document 1). The turbo decoder includes two decoding processing units, and one decoding processing unit calculates a log likelihood ratio (likelihood information) of encoded data included in the radio signal. The calculated log likelihood ratio is fed back to the other decoding processing unit, and the decoding process is repeated up to the set number of times.
Japanese Patent No. 3714910 (pages 13-15, FIG. 1)

  However, the conventional receiver, specifically, the radio signal receiving apparatus has the following problems. That is, when there are large differences in the power values of a large number of radio signals received by the receiver, radio signals with high power values interfere with radio signals with low power values. For this reason, there has been a problem that a large error occurs in the calculation result of the log-likelihood ratio and the correction rate of transmission error is lowered.

  Therefore, the present invention has been made in view of such a situation, and provides a radio signal receiving apparatus and a radio signal receiving method capable of suppressing a reduction in transmission error correction rate due to interference between received radio signals. The purpose is to do.

  In order to solve the problems described above, the present invention has the following features. First, the first feature of the present invention is that a reception unit (MIMO equalizer 211) that receives a plurality of radio signals (radio signals S1 to Sn) in the same frequency band and the radio signal according to a predetermined error correction code. A decoding processing unit that decodes the encoded data (encoded data D1) and repeatedly decodes the encoded data based on likelihood information (log likelihood ratio LLR) indicating the likelihood of the encoded data ( A likelihood signal determination unit (log likelihood ratio process) for determining whether or not the reliability of the likelihood information is greater than or equal to a predetermined threshold value. Unit 253) and the encoded data determined by the likelihood information determination unit that the likelihood information is less than a predetermined reliability among the encoded data included in the radio signal received by the reception unit Store A data storage unit (buffer 265a), wherein the decoding processing unit determines that the encoded data stored in the data storage unit is greater than or equal to a predetermined reliability by the likelihood information determination unit. When it is determined, the gist is to decode the encoded data stored in the data storage unit.

  According to such a radio signal receiving apparatus, when it is determined that the likelihood information of the encoded data is equal to or higher than the predetermined reliability, the encoded data stored in the data storage unit is decoded. For this reason, encoded data whose likelihood information is less than a predetermined reliability due to interference between radio signals or the like is not decoded until the likelihood information exceeds a predetermined reliability. That is, according to such a radio signal receiving apparatus, it is possible to suppress a reduction in transmission error correction rate due to interference between received radio signals.

  A second feature of the present invention relates to the first feature of the present invention, and relates to a channel state acquisition unit (a channel state acquisition unit 207) that acquires a channel state of the radio signal, and the channel state acquisition. The present invention is further characterized by further comprising a repetition number determination unit (repetition number determination unit 209) that determines the number of repetitions of decoding of the encoded data based on the state of the propagation path acquired by the unit.

  A third feature of the present invention relates to the second feature of the present invention, and is an error state detection unit (error calculation) for detecting an error state included in a decoding result (decoded data D2) obtained by decoding the encoded data. 273), the decoding processing unit, when the error detected by the error state detection unit is less than a predetermined threshold, regardless of whether or not the decoding of the number of repetitions is completed The gist is to stop decoding the encoded data.

  A fourth feature of the present invention is according to the second feature of the present invention, wherein the decoding processing section sequentially decodes a radio signal having a good propagation path state acquired by the propagation path state acquisition section. Is the gist.

  The fifth feature of the present invention is that a plurality of radio signals in the same frequency band are received, the encoded data included in the radio signal is decoded according to a predetermined error correction code, and the likelihood of the encoded data is indicated. A radio signal receiving method for repeatedly decoding the encoded data based on likelihood information, the step of determining whether the reliability of the likelihood information is equal to or higher than a predetermined threshold, and included in the received radio signal Storing the encoded data in which the likelihood information is determined to be less than a predetermined reliability among the encoded data to be stored in a data storage unit, and in the decoding step, the data storage unit The gist is to decode the encoded data stored in the data storage unit when it is determined that the likelihood information of the stored encoded data is greater than or equal to a predetermined reliability. .

  A sixth feature of the present invention relates to the fifth feature of the present invention, wherein a step of acquiring a state of a propagation path of the radio signal and a step of acquiring the encoded data based on the acquired state of the propagation path. And a step of determining the number of decoding iterations.

  A seventh feature of the present invention relates to the sixth feature of the present invention, and further comprises a step of detecting an error state included in the decoding result, wherein in the decoding step, the detected error is a predetermined value. If it is less than the threshold value, the gist is to stop the decoding of the encoded data regardless of whether or not the decoding of the number of repetitions has been completed.

  The eighth feature of the present invention is related to the sixth feature of the present invention, and is summarized in that the decoding step sequentially decodes the acquired radio signal having a good state of the propagation path.

  According to the features of the present invention, it is possible to provide a radio signal receiving apparatus and a radio signal receiving method capable of suppressing a reduction in transmission error correction rate due to interference between received radio signals.

  Next, an embodiment of the present invention will be described. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Overall schematic configuration of wireless communication system)
FIG. 1 is an overall schematic configuration diagram of a wireless communication system 10 according to the present embodiment. As shown in FIG. 1, the wireless communication system 10 includes a transmitter 100 and a receiver 200. The transmitter 100 and the receiver 200 employ multiple input multiple output (MIMO) that improves throughput using a large number of antennas that transmit and receive radio signals in the same frequency band.

  Transmitter 100 simultaneously transmits radio signals S1 to Sn in the same frequency band using antennas 101a to 101n. The receiver 200 receives the radio signals S1 to Sn using the antennas 201a to 201n. Furthermore, the receiver 200 separates the received radio signals S1 to Sn and extracts encoded data D1 (not shown in FIG. 1, refer to FIG. 3) included in the radio signals S1 to Sn. In the present embodiment, the receiver 200 constitutes a radio signal receiving device.

  In the transmitter 100 and the receiver 200, a turbo code is used as an error correction code method.

(Functional block configuration of wireless signal receiving device)
Next, a functional block configuration of the receiver 200 configuring the wireless signal receiving apparatus in the present embodiment will be described. FIG. 2 is an overall functional block diagram of the receiver 200. FIG. 3 is a detailed functional block diagram of a turbo decoder 250 included in the receiver 200.

(1) Overall Block Configuration As shown in FIG. 2, the receiver 200 includes a MIMO equalizer 211 and a turbo decoder 250. A plurality of antennas, specifically, antennas 201a to 201n are connected to the MIMO equalizer 211.

  A channel estimation unit 203 is connected to the antennas 201a to 201n. A training symbol generation unit 205 is connected to the channel estimation unit 203. Channel estimation section 203 performs channel estimation of radio signals S1 to Sn received via antennas 201a to 201n based on the training symbols output from training symbol generation section 205. Specifically, the channel estimation unit 203 estimates the propagation path state (multipath) of the radio signals S1 to Sn based on the training symbols.

  A channel state acquisition unit 207 is connected to the channel estimation unit 203. The propagation path state acquisition unit 207 acquires the state of the propagation path of the radio signals S1 to Sn based on the result of channel estimation by the channel estimation unit 203. Specifically, the propagation path state acquisition unit 207 acquires the received power values, RSSI, CINR, and the like of the radio signals S1 to Sn.

  The propagation state determination unit 207 is connected to a repetition number determination unit 209. The number-of-repetitions determination unit 209 determines the turbo of the encoded data D1 (see FIG. 3) included in the radio signals S1 to Sn based on the propagation path states of the wireless signals S1 to Sn acquired by the propagation path state acquisition unit 207. The number of decoding iterations is determined.

  The number of repetitions of decoding of the encoded data D1 determined by the repetition number determination unit 209 is output to the MIMO equalizer 211.

  The MIMO equalizer 211 receives the radio signals S1 to Sn using the antennas 201a to 201n. In the present embodiment, the MIMO equalizer 211 constitutes a receiving unit. Specifically, the MIMO equalizer 211 separates the radio signals S1 to Sn received at the same time, and executes a predetermined matrix operation, thereby encoding data D1 included in the radio signals S1 to Sn (see FIG. 3). ).

  The MIMO equalizer 211 outputs the extracted encoded data D1 to the turbo decoder 250. Specifically, the MIMO equalizer 211 determines the magnitude of the power value of the received radio signals S1 to Sn and the log likelihood ratio LLR fed back from the turbo decoder 250 (not shown in FIG. 2, see FIG. 3). ) To sort the radio signals S1 to Sn. The MIMO equalizer 211 outputs the encoded data D1 included in the radio signal to the turbo decoder 250 corresponding to the order according to the sorted order.

  A plurality of turbo decoders 250 are provided corresponding to radio signals. The turbo decoder 250 decodes the encoded data D1 output from the MIMO equalizer 211, and outputs decoded data D2 (not shown in FIG. 2, refer to FIG. 3). The turbo decoder 250 decodes the encoded data D1 encoded based on the turbo code.

(2) Detailed Block Configuration of Turbo Decoder 250 As shown in FIG. 3, the turbo decoder 250 includes a demapping unit 251, a log likelihood ratio processing unit 253, a separation unit 255, an interleaver 257, a decoding processing unit 260, and an output. Unit 271 and error calculation unit 273.

  The demapping unit 251 performs a demapping process on the encoded data D1 output from the MIMO equalizer 211, and rearranges it into a predetermined bit sequence. The demapping unit 251 outputs a predetermined bit sequence in which the encoded data D1 is rearranged to the log likelihood ratio processing unit 253.

  The log likelihood ratio processing unit 253 calculates a predetermined bit sequence output from the demapping unit 251, that is, the log likelihood ratio LLR (likelihood information) of the encoded data D1. The log likelihood ratio LLR indicates the likelihood (likelihood) of the encoded data D1. The log likelihood ratio processing unit 253 outputs the calculated log likelihood ratio LLR to the decoding processing unit 260. Further, the log likelihood ratio LLR is fed back to the MIMO equalizer 211.

  In the present embodiment, the log likelihood ratio processing unit 253 determines whether or not the reliability of the calculated log likelihood ratio LLR is equal to or greater than a predetermined threshold. In the present embodiment, the log likelihood ratio processing unit 253 constitutes a likelihood information determination unit. Specifically, the log likelihood ratio processing unit 253 determines the reliability of the log likelihood ratio LLR according to the power value of the radio signal including the encoded data D1, and whether the reliability is equal to or higher than a predetermined threshold. Determine whether or not.

  The separation unit 255 performs depuncturing of the encoded data D1 relayed by the log likelihood ratio processing unit 253, and causes the encoded data D1 to be decoded by the decoding processing unit 260, so that the encoded data D1 is predetermined. It is separated into multiple data according to the format. The encoded data D1 separated into a plurality of data is output to the interleaver 257 and the decoding processing unit 260.

  The interleaver 257 performs interleaving processing on the encoded data D1 (a plurality of data) output from the separation unit 255, and outputs the encoded data D1 subjected to the interleaving processing to the decoding processing unit 260.

  The decoding processing unit 260 includes a decoding unit 261, an interleaver 263, a decoding unit 265, and a deinterleaver 267.

  The decoding processing unit 260 decodes the encoded data D1 according to a turbo code (predetermined error correction code). Furthermore, the decoding processing unit 260 repeatedly decodes the encoded data D1 based on the log likelihood ratio LLR.

  Specifically, the decoding unit 265 that has acquired the encoded data D1 via the interleaver 263 performs a decoding process on the encoded data D1 using the log likelihood ratio LLR and the encoded data D1. Furthermore, the decoding unit 265 calculates the log likelihood ratio LLR of the encoded data D1, and notifies the decoding unit 261 of the calculated log likelihood ratio LLR via the deinterleaver 267.

  The decoding unit 261 performs encoding using the log likelihood ratio LLR notified from the decoding unit 265 and the encoded data D1 output from the separation unit 255 in the second and subsequent decoding processes of the encoded data D1. A decryption process of the data D1 is executed.

  The interleaver 263 performs interleaving processing of the encoded data D1. The deinterleaver 267 performs a deinterleaving process on the encoded data D1 that has been subjected to the interleaving process.

  In addition, the decoding unit 265 is provided with a buffer 265a that stores the encoded data D1 determined by the log likelihood ratio processing unit 253 that the log likelihood ratio LLR is less than a predetermined reliability. The buffer 265a constitutes a data storage unit.

  When the log likelihood ratio LLR of the encoded data D1 stored in the buffer 265a is determined to be greater than or equal to a predetermined reliability by the log likelihood ratio processing unit 253, the decoding unit 265 encodes the code stored in the buffer 265a. The encrypted data D1 is decrypted.

  An output unit 271 and an error calculation unit 273 are connected to the decoding processing unit 260, specifically, the deinterleaver 267.

  The output unit 271 outputs the decoded data D2 (decoding result) obtained by decoding the encoded data D1 by the decoding processing unit 260 to a lower block, for example, a baseband processing unit (not shown).

  The error calculator 273 detects an error state included in the decoded data D2. In the present embodiment, the error calculation unit 273 constitutes an error state detection unit.

  In the present embodiment, when the error included in the decoded data D2 detected by the error calculation unit 273 is less than a predetermined threshold, the decoding processing unit 260 decodes the number of repetitions determined by the repetition number determination unit 209. The decoding of the encoded data D1 is stopped regardless of whether or not it is completed.

  Further, as described above, in this embodiment, the MIMO equalizer 211 outputs the encoded data D1 included in a predetermined number of radio signals having a large power value to the turbo decoder 250. That is, the decoding processing unit 260 sequentially decodes radio signals with good propagation path states acquired by the propagation path state acquisition unit 207.

(Operation of wireless communication system)
Next, the operation of the wireless communication system 10 will be described. Specifically, the decoding processing operation of the encoded data D1 by the receiver 200 configuring the wireless signal receiving device in the present embodiment will be described. FIG. 4 shows a decoding processing operation flow of the encoded data D1 by the receiver 200.

  As shown in FIG. 4, in step S10, the receiver 200 receives the radio signals S1 to Sn via the antennas 201a to 201n.

  In step S20, the receiver 200 performs channel estimation of the received radio signals S1 to Sn.

  In step S30, the receiver 200 acquires the propagation path states of the radio signals S1 to Sn based on the channel estimation results of the radio signals S1 to Sn. Specifically, the receiver 200 acquires the received power values, RSSI, CINR, and the like of the radio signals S1 to Sn.

  In step S40, the receiver 200 determines the number of repetitions of turbo decoding of the encoded data D1 included in the radio signals S1 to Sn based on the acquired propagation path states of the radio signals S1 to Sn.

  In step S50, the receiver 200 sorts the radio signals S1 to Sn in descending order of the power values of the received radio signals S1 to Sn. Specifically, the receiver 200 sorts the radio signals S1 to Sn according to the power values of the radio signals S1 to Sn and the log likelihood ratio LLR fed back from the turbo decoder 250.

  In step S60, the receiver 200 outputs the encoded data D1 included in the radio signal to the turbo decoder 250 corresponding to the order according to the sorted order.

  In step S70, the receiver 200 calculates a log likelihood ratio LLR of the encoded data D1.

  In step S80, the receiver 200 checks the value of the calculated log likelihood ratio LLR.

  In step S90, the receiver 200 determines whether or not the log likelihood ratio LLR is greater than or equal to a predetermined reliability.

  When the log likelihood ratio LLR is equal to or higher than the predetermined reliability (YES in step S90), in step S100, the receiver 200 determines whether or not the value of the log likelihood ratio LLR is checked for the first time.

  When the log likelihood ratio LLR is less than the predetermined reliability (NO in step S90), in step S110, the receiver 200 stores the encoded data D1 in the buffer 265a.

  When the log likelihood ratio LLR value is not tested for the first time (NO in step S100), in step S120, the receiver 200 reads the encoded data D1 stored in the buffer 265a. Note that the receiver 200 omits the process of step S120 when the encoded data D1 is not stored in the buffer 265a.

  When the log likelihood ratio LLR value is checked for the first time (YES in step S100), and after executing the process of step S120, in step S130, the receiver 200 repeats the number of times of turbo decoding determined in step S40 Based on the above, the decoding process is executed.

  In step S140, the receiver 200 determines that there is no error in the decoded data D2 obtained by decoding the encoded data D1.

  If there is no error in the decoded data D2 (YES in step S140), the receiver 200 ends the decoding process of the encoded data D1. On the other hand, when there is an error in the decoded data D2 (NO in step S140), the receiver 200 repeats the process in step S130.

(Action / Effect)
According to the radio communication system 10, specifically, the receiver 200, when the log likelihood ratio LLR of the encoded data D1 is determined to be equal to or higher than a predetermined reliability, the encoded data stored in the data storage unit D1 is decoded. For this reason, the encoded data D1 having the log likelihood ratio LLR less than the predetermined reliability due to interference between the radio signals S1 to Sn is not decoded until the log likelihood ratio LLR is equal to or higher than the predetermined reliability. That is, according to the receiver 200, it is possible to suppress a reduction in transmission error correction rate due to interference between received radio signals S1 to Sn.

  In the present embodiment, the number of repetitions of turbo decoding of the encoded data D1 is determined based on the propagation path states of the radio signals S1 to Sn. For this reason, when the characteristics of the propagation path are good, the time required for the decoding process can be shortened.

  That is, when the propagation path characteristics are good, the transmission error included in the decoded data D2 (decoding result) converges to a predetermined level or less at an early stage. However, in the conventional receiver, even when a transmission error included in the decoding result converges below a predetermined level at an early stage, the decoding process is repeated up to the determined number of times. The receiver 200 can solve the problem that the time required for the decoding process is unnecessarily long.

  Furthermore, in the present embodiment, when the error detected by the error calculation unit 273 is less than a predetermined threshold, the encoded data D1 is decoded regardless of whether or not the decoding of the number of iterations of turbo decoding has been completed. Canceled. For this reason, the time required for the decoding process can be further shortened.

  In the present embodiment, the wireless signal S1 to Sn acquired by the propagation path state acquisition unit 207 is sequentially decoded from the wireless signal having a good propagation path state. That is, decoding is performed from a radio signal that is highly likely that the log likelihood ratio LLR is equal to or higher than a predetermined reliability. For this reason, the time required for the decoding process can be further shortened.

(Other embodiments)
As described above, the contents of the present invention have been disclosed through one embodiment of the present invention. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments will be apparent to those skilled in the art.

  For example, in the above-described embodiment, the radio signals S1 to Sn are sequentially decoded from radio signals having good propagation path states. However, it is not always necessary to sequentially decode radio signals having good propagation path conditions. .

  In the above-described embodiment, when the error detected by the error calculation unit 273 is less than a predetermined threshold, the decoding of the encoded data D1 is stopped regardless of whether or not the decoding of the number of iterations of turbo decoding has been completed. However, the decoding of the encoded data D1 does not have to be stopped before the decoding of the number of repetitions is completed.

  In the above-described embodiment, the number of repetitions of turbo decoding of the encoded data D1 is determined based on the state of the propagation path of the radio signals S1 to Sn. However, the number of repetitions may not be determined.

  In the above-described embodiment, the log likelihood ratio LLR is used. However, the log likelihood ratio LLR is not necessarily required as long as the information can indicate the likelihood (likelihood) of the encoded data D1. . Further, in the above-described embodiment, the turbo code is used as the error correction code. However, any error correction code that repeats the decoding process based on the likelihood information of the encoded data is other than the turbo code. Also good.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

1 is an overall schematic configuration diagram of a wireless communication system according to an embodiment of the present invention. It is a whole functional block diagram of the radio signal receiver (receiver 200) concerning the embodiment of the present invention. It is a detailed functional block diagram of a turbo decoder included in a radio signal receiving apparatus according to an embodiment of the present invention. It is a decoding processing operation | movement flow of the radio | wireless signal receiver which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Wireless communication system, 100 ... Transmitter, 101a-101n ... Antenna, 200 ... Receiver, 201a-201n ... Antenna, 203 ... Channel estimation part, 205 ... Training symbol generation part, 207 ... Propagation path state acquisition part, 209 ... iteration number determination unit, 211 ... MIMO equalizer, 250 ... turbo decoder, 251 ... demapping unit, 253 ... log likelihood ratio processing unit, 255 ... demultiplexing unit, 257, 263 ... interleaver, 260 ... decoding processing unit 261, 265 decoding unit, 265a ... buffer, 267 ... deinterleaver, 271 ... output unit, 273 ... error operation unit, D1 ... encoded data, D2 ... decoded data, LLR ... log likelihood ratio, S1-Sn ... Wireless signal

Claims (8)

A receiver for receiving a plurality of radio signals in the same frequency band;
A decoding processing unit that decodes encoded data included in the radio signal according to a predetermined error correction code, and that repeatedly decodes the encoded data based on likelihood information indicating a likelihood of the encoded data. A wireless signal receiving device,
A likelihood information determination unit for determining whether the reliability of the likelihood information is equal to or greater than a predetermined threshold;
Data storage for storing encoded data determined by the likelihood information determination unit as being less than a predetermined reliability among the encoded data included in the radio signal received by the reception unit With
The decoding processing unit stores the encoded data stored in the data storage unit in the data storage unit when the likelihood information determination unit determines that the likelihood information is equal to or higher than a predetermined reliability. A radio signal receiving apparatus for decoding the encoded data. A propagation path state acquisition unit for acquiring a state of a propagation path of the wireless signal;
The radio signal receiving apparatus according to claim 1, further comprising: an iterative number determination unit that determines an iterative number of times of decoding the encoded data based on the state of the propagation path acquired by the propagation path state acquisition unit. An error state detection unit for detecting an error state included in a decoding result obtained by decoding the encoded data;
The decoding processing unit, when the error detected by the error state detecting unit is less than a predetermined threshold, stops decoding the encoded data regardless of whether or not the decoding of the number of repetitions is completed The radio signal receiving apparatus according to claim 2.   The radio signal receiving device according to claim 2, wherein the decoding processing unit sequentially decodes radio signals having a good propagation path state acquired by the propagation path state acquisition unit. Receiving a plurality of radio signals in the same frequency band, decoding encoded data included in the radio signal according to a predetermined error correction code, and encoding the encoding based on likelihood information indicating the likelihood of the encoded data A wireless signal receiving method for repeatedly decoding data,
Determining whether the reliability of the likelihood information is greater than or equal to a predetermined threshold;
A step of storing, in a data storage unit, encoded data in which the likelihood information is determined to be less than a predetermined reliability among the encoded data included in the received radio signal;
In the decoding step, when it is determined that the likelihood information of the encoded data stored in the data storage unit is equal to or higher than a predetermined reliability, the encoded data stored in the data storage unit is Radio signal receiving method for decoding. Obtaining a state of a propagation path of the wireless signal;
The wireless signal receiving method according to claim 5, further comprising a step of determining the number of repetitions of decoding of the encoded data based on the acquired state of the propagation path. A step of detecting an error state included in a decoding result obtained by decoding the encoded data;
7. The decoding step according to claim 6, wherein when the detected error is smaller than a predetermined threshold, decoding of the encoded data is stopped regardless of whether or not decoding of the number of repetitions is completed. Wireless signal reception method.   The radio signal receiving method according to claim 6, wherein, in the decoding step, the acquired radio signal is sequentially decoded from a radio signal having a good state.