JP2006229693A - Coding device, decoding device, transmitter, receiver and coding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a time required until data are decoded by improving data decoding performance in a decoding method for using a plurality of media to transmit or record data. <P>SOLUTION: A coding rate determining part 108 determines a coding rate corresponding to each carrier from the propagation environment information of the each carrier. A puncturing part 103 performs puncturing in each divided block on the basis of the coding rate determined by the coding rate determining part 108. A carrier dividing part 104 allocates punctured divided blocks to different carriers. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an encoding device, a decoding device, a transmission device, a reception device, and an encoding method, and in particular, an encoding device, a decoding device, a transmission device, and the like that use an error correction code in a multicarrier communication system, an optical disc, and the like The present invention relates to a receiving apparatus and an encoding method.

  A transmission apparatus that performs a multicarrier communication scheme may use a block code called a turbo code as an error correction code for the purpose of improving error correction capability. Specifically, the interleaved information data is encoded by the encoder, the encoded data string is punctured, the punctured data string is divided into a plurality of blocks, and each divided block is Each is assigned to a plurality of different carriers and transmitted.

  FIG. 7 shows the state of the puncturing operation when the transmission apparatus described above is adapted to multicarrier communication. FIG. 7 shows an example in which a 1-input 3-output encoder is used. FIG. 7A shows the states of the data strings Xk, Zk, and Z′k output from the encoder when the input data Xk is input to the encoder. FIG. 7B shows a state in which puncturing (coding rate 3/4) is performed on the data strings Xk, Zk, and Z′k in FIG. FIG. 7C shows a state in which the punctured data in FIG. 7B is divided into a plurality of blocks. Each data is assigned to a plurality of different carriers (carrier 1, carrier 2,..., Carrier 4) for each divided block and transmitted.

For example, Patent Document 1 discloses a transmission apparatus that performs such puncturing. This transmission apparatus performs puncturing by changing the coding rate according to the propagation environment. As a result, even when the propagation environment fluctuates in time due to the receiver moving in an environment where signals with random phases that have passed through multiple propagation paths due to reflection, diffraction, etc. by terrain or buildings are combined, The effect of error correction can be improved according to the propagation environment.
JP 2003-69531 A

  However, the transmission apparatus used in the conventional multicarrier communication system has a problem that the transmission efficiency is lowered as a whole when the propagation environment of each carrier is different. That is, the occurrence of errors is not uniform depending on the state of the propagation environment of each carrier, the interleaved information data is encoded by the encoder, the encoded data is divided into a plurality of blocks, When blocks are allocated to a plurality of different carriers for transmission, the effect of error correction of the entire information data after interleaving before division may be reduced due to the influence of a carrier having a poor propagation environment. In other words, if the error correction effect of a certain carrier is reduced and the data assigned to that carrier is erroneous due to a transmission error, it is necessary to retransmit the data assigned to all carriers or the carrier in which the transmission error has occurred. In some cases, the time required for decoding the data increases.

  The present invention has been made in view of this point, and in an encoding method for transmitting or recording data using a plurality of media, improves the data decoding performance and shortens the time required to decode the data. It is an object of the present invention to provide an encoding device, a decoding device, a transmission device, a reception device, and an encoding method.

  An encoding apparatus according to the present invention is an encoding apparatus that assigns information data and a parity bit added to the information data to each of a plurality of media that transmit or record data, and that corresponds to the demodulation quality of each medium. Coding rate determining means for determining a coding rate for each medium, puncturing means for performing puncturing to thin out the parity bits added to the information data at the determined coding rate for each medium, and information data And an allocating unit that allocates the punctured parity bits to each of the plurality of media.

  An encoding method according to the present invention is an encoding method for allocating information data and a parity bit added to the information data to each of a plurality of media for transmitting or recording data, and according to the demodulation quality of each medium. Determining a coding rate for each medium, puncturing the parity bits added to the information data at a determined coding rate for each medium, and information data and parity bits after puncturing Assigning to each of the plurality of media.

  According to these, the coding rate for each medium is determined according to the demodulation quality of each medium of a plurality of media for transmitting or recording data, and the code for each medium for which the parity bit added to the information data is determined. Puncturing is performed at a conversion rate, and information data and parity bits after puncturing are assigned to each of multiple media, improving the error correction effect for each media even when the demodulation quality of each media differs It becomes possible to do. Therefore, data can be efficiently encoded in a multi-carrier communication system, an optical disk, or the like. The same error correction code can be used for a plurality of media.

  According to the present invention, in an encoding method for transmitting or recording data using a plurality of media, it is possible to improve the data encoding performance and reduce the time required to decode the data.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, a case will be described in which a carrier is used as a medium for transmitting data, and a carrier propagation environment is used as the demodulation quality of the medium.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a transmission apparatus according to Embodiment 1 of the present invention. 1, a transmission apparatus 100 includes an encoding unit 101, a block division unit 102, a puncturing unit 103, a carrier division unit 104, a transmission unit 105, a reception unit 106, a propagation environment information extraction unit 107, and a coding rate determination unit 108. have.

  Encoding section 101 uses a block code for the purpose of improving error correction capability, encodes information data, and outputs the encoded data string to block dividing section 102. Examples of the block code include a Hamming code, an LDPC (Low Density Parity Check) code, and a turbo code adopted in 3GPP. For example, when a turbo code employed in 3GPP is used as a block code, the encoding unit 101 includes two element encoders. At this time, the encoding unit 101 functions as a 1-input 3-output encoder, and when 1 series of information data is input, 1 series of information data and 2 series of parity bits (hereinafter referred to as “data string”). Is output.

  The block division unit 102 divides the data sequence into the same number of blocks as the number of carriers assigned by the carrier division unit 104, and outputs the divided data sequence to the puncturing unit 103. Here, the carrier is a medium for transmitting data.

  Puncturing section 103 performs puncturing for each divided data string, that is, for each divided block, based on the coding rate determined by coding rate determining section 108, and divides the punctured divided block into a carrier dividing section. To 104. The operation of determining the coding rate by the coding rate determining unit 108 will be described later.

  Carrier dividing section 104 assigns the divided blocks after puncturing to different carriers, and outputs a multicarrier signal obtained by inverse Fourier transform to transmitting section 105.

  Transmitting section 105 performs transmission processing (modulation, D / A conversion, up-conversion, etc.) on the multicarrier signal and transmits it through the antenna.

  The reception unit 106 receives a signal including propagation environment information notified from the reception device side, performs reception processing (down-conversion, demodulation, A / D conversion, etc.), and then transmits the demodulated data to the propagation environment information extraction unit. It outputs to 107. Here, the propagation environment information indicates the demodulation quality of the carrier when the carrier is used as a medium for transmitting data.

  The propagation environment information extraction unit 107 extracts propagation environment information indicating the state of the propagation environment of each carrier from the demodulated data, and outputs the propagation environment information to the coding rate determination unit 108. Propagation environment information is information that can be used to estimate transmission path loss, such as carrier power to noise power ratio, signal power to noise power ratio, BER (Bit Error Rate), and PER (Packet Error Rate) measured on the receiving device side. Say.

  The coding rate determination unit 108 determines the coding rate corresponding to each carrier from the propagation environment information of each carrier. For example, when the BER of a certain carrier is higher than a predetermined value and the propagation environment is worse than that of other carriers, the coding rate determination unit 108 sets the coding rate corresponding to the carrier with a bad propagation environment to another with a good propagation environment. Is set lower than the coding rate corresponding to the carrier. Thereby, the effect of error correction of the carrier set with a low coding rate is improved. And the rate of data error on the receiving device side is reduced by improving the error correction effect. As a result, processing such as retransmission is reduced, and a reduction in transmission efficiency can be prevented. On the other hand, when the BER of a certain carrier is lower than a predetermined value and the propagation environment is better than that of other carriers, the coding rate determination unit 108 sets the coding rate corresponding to the carrier with a good propagation environment to the other with a poor propagation environment. Higher than the coding rate corresponding to the carrier.

  Also, the coding rate determination unit 108 has a history of propagation environment information, coding rate, number of retransmissions, etc. in past transmission, and coding when retransmission processing is not performed from the propagation environment information of each carrier. A method of setting the rate as the encoding rate used this time may be used. Retransmission processing is usually performed when the error correction effect by encoding cannot be obtained and the data is erroneous on the receiving device side, and when the error correction effect is obtained by encoding and the data is demodulated normally Is not given. That is, the coding rate when the retransmission process is not performed can be said to have a proven value as a coding rate that can eliminate a transmission error due to a propagation environment by the effect of error correction. In general, when the propagation environment is good, even when the coding rate is set high, the effect of error correction is obtained by coding, and data is demodulated normally. On the other hand, when the propagation environment is bad, the effect of error correction by coding can be obtained by setting the coding rate low. Therefore, when the coding rate is determined based on the above-described history, the coding rate corresponding to a carrier having a good propagation environment is higher than the coding rate corresponding to another carrier and corresponds to a carrier having a bad propagation environment. The coding rate to be set is set lower than the coding rates corresponding to other carriers, and a proven coding rate is set as a coding rate that does not require retransmission processing.

  FIG. 2 is a block diagram showing a configuration of the receiving apparatus according to Embodiment 1. In FIG. 2, the reception apparatus 200 includes a reception unit 201, a depuncturing unit 202, a block synthesis unit 203, a decoding unit 204, a propagation environment information acquisition unit 205, and a transmission unit 206.

  The receiving unit 201 receives the multicarrier signal, performs predetermined reception processing (down-conversion, demodulation, A / D conversion, etc.), and outputs demodulated data after the reception processing to the depuncturing unit 202. In addition, the receiving unit 201 demodulates information necessary for decoding such as a coding rate and a divided block length applied to each divided block notified from the transmitting apparatus side, and outputs the demodulated information to the depuncturing unit 202.

  Depuncturing section 202 depunctures the demodulated data for each divided block assigned to each carrier, and outputs the depunctured data sequence to block combining section 203.

  The block synthesis unit 203 synthesizes the depunctured data sequence with the data sequence before being divided into a plurality of blocks, and outputs the synthesized data sequence to the decoding unit 204.

  The decoding unit 204 acquires information data by decoding the data string before being divided into a plurality of blocks in units of the block length before the division, and outputs the information data to a device in a subsequent process.

  The propagation environment information acquisition unit 205 acquires data that can be propagation environment information, such as BER, PER, carrier power to noise power ratio, and signal power to noise power ratio. For example, a BER or PER is measured from known data transmitted in advance from the transmitting apparatus, or a signal power to noise power ratio or a carrier power to noise power ratio is measured. The measurement of the propagation environment information may be performed by a device other than the reception device 200. In this case, the reception unit 201 includes a signal including the propagation environment information notified from another device that measures the propagation environment information. And outputs the received signal to the propagation environment information acquisition unit 205. Then, the propagation environment information acquisition unit 205 acquires the propagation environment information from the signal output from the reception unit 201. The propagation environment information acquisition unit 205 outputs the acquired propagation environment information to the transmission unit 206. Here, as described above, the propagation environment information indicates the demodulation quality of the carrier when the carrier is used as a medium for transmitting data.

  The transmission unit 206 transmits the propagation environment information acquired by the propagation environment information acquisition unit 205 to the transmission apparatus side via the antenna.

  Next, the operation of determining the coding rate by the transmission apparatus 100 configured as described above will be described below.

  The transmission device 100 receives a signal including the propagation environment information notified from the reception device 200 by the reception unit 106, and extracts the propagation environment information by the propagation environment information extraction unit 107.

  The extracted propagation environment information includes information such as carrier power-to-noise power ratio, signal power-to-noise power ratio, BER, and PER indicating the state of the propagation environment of each carrier. Output to the conversion rate determination unit 108.

  When the propagation environment information is output to coding rate determining section 108, coding rate determining section 108 determines the coding rate corresponding to each carrier based on the propagation environment information of each carrier. Specifically, the coding rate corresponding to a carrier having a poor propagation environment is set low, and the coding rate corresponding to a carrier having a good propagation environment is set high. For example, when the BER of a certain carrier is high and the propagation environment is poor compared to other carriers, the coding rate corresponding to that carrier is set lower than the coding rate corresponding to the other carrier. Thereby, the effect of error correction in the carrier set with a low coding rate is improved. Then, by improving the error correction effect, the ratio of erroneous data on the receiving device side is reduced. As a result, processing such as retransmission is reduced, and a reduction in transmission efficiency can be prevented. The coding rate determined by the coding rate determination unit 108 based on the propagation environment of each carrier is output to the puncturing unit 103.

  On the other hand, the information data is subjected to error correction coding processing in the coding unit 101, and a parity bit is added to the information data and output. The information data and the parity bit (data string) are divided into the same number of blocks as the number of carriers assigned by the carrier dividing unit 104 by the block dividing unit 102. The divided data string, that is, the divided block is output to the puncturing unit 103, and puncturing is performed for each divided block based on the coding rate determined by the coding rate determining unit 108 in the puncturing unit 103. The At this time, the coding rate used in puncturing is determined based on the propagation environment of each carrier by the coding rate determination unit 108 as described above. That is, when the propagation environment of a certain carrier is worse than the other carriers, the coding rate corresponding to the carrier with the poor propagation environment is set lower than the coding rate corresponding to the other carrier. As a result, in a divided block corresponding to a carrier with a poor propagation environment, the number of parity bits deleted by puncturing is small. If the number of parity bits to be deleted is small, the error correction effect is improved. In other words, the coding rate is determined based on the propagation environment of each carrier, and error correction is performed for each carrier according to the propagation environment of the carrier by providing a difference in the number of parity bits that are punctured and deleted in the corresponding divided block. Can improve the effect.

  The punctured divided blocks are allocated to a plurality of different carriers by the carrier dividing unit 104, and a multicarrier signal obtained by inverse Fourier transform is output to the transmitting unit 105. The multicarrier signal is transmitted through the antenna after being subjected to transmission processing (D / A conversion, orthogonal modulation, up-conversion to a radio frequency band, etc.) by the transmission unit 105.

  The multicarrier signal transmitted from the transmission device 100 is subjected to reception processing (down-conversion, demodulation, A / D conversion, etc.) by the reception unit 201 via the antenna of the reception device 200, and then divided into blocks in the depuncturing unit 202. Each block is depunctured, and is synthesized by the block synthesizing unit 203 into a data string before division, then decoded by the decoding unit 204, and output as information data to a device in a subsequent process.

  Next, a specific example of the puncturing operation in the first embodiment will be described with reference to FIG. In FIG. 3, each square represents a predetermined unit (bit, symbol, etc.) of data. FIG. 3 shows an example in which the encoding unit 101 functions as a 1-input 3-output encoder.

  As shown in FIG. 3A, the information data Xk (k: 1, 2,..., 36) is subjected to error correction coding processing in the coding unit 101, and the information data Xk is subjected to parity bits Zk, Z ′. k is added and output.

  Then, the information data Xk and the parity bits Zk and Z′k (data string) are divided into blocks having the same number as the number of carriers allocated by the carrier dividing unit 104 in the block dividing unit 102. FIG. 3B shows a state in which the data string is divided into four blocks surrounded by a thick frame in the block dividing unit 102.

  The divided data string (FIG. 3B) is punctured for each divided block in the puncturing section 103 based on the coding rate determined by the coding rate determining section 108 (FIG. 3 ( c)). In FIG. 3C, hatched squares represent data deleted as a result of puncturing by the puncturing unit 103. Here, FIG. 3C shows an example in which the propagation environment of carrier 1 is worse than that of other carrier 2, carrier 3, and carrier 4, and coding rate determination section 108 uses other carrier 2, carrier 3, While the coding rate applied to the carrier 4 is set to 3/4, the coding rate applied to the carrier 1 is set as low as 1/2. By setting the coding rate applied to the carrier 1 having a poor propagation environment to be low and improving the error correction effect, it is possible to prevent the occurrence of errors in the carrier 1, and the rate of erroneous data on the receiving device side is reduced. To do. As a result, processing such as retransmission is reduced, and it is possible to improve transmission efficiency as the whole data before division. In the example described above, only the coding rate applied to carrier 1 is set low, but setting the coding rate applied to each carrier to a different value for each carrier is also applicable to all carriers. It is also possible to set the same coding rate. The punctured data string is allocated to four different carriers in the carrier dividing unit 104, respectively.

  Thus, according to the present embodiment, the coding rate applied to each carrier is set according to the propagation environment of each carrier. For this reason, even if the propagation environment of each carrier is different, the effect of error correction can be improved for each carrier, and transmission errors can be reduced. As a result, processing such as retransmission is reduced, and the entire data before division can be efficiently transmitted. In addition, since the coding rate applied to each carrier can be determined for each carrier and the loss of each carrier can be compensated for, it is possible to encode all carriers with the same error correction code and propagation. There is no need to prepare an error correction code for each carrier having a different loss.

  In the present embodiment, a case has been described in which a carrier is used as a medium for transmitting data, and a carrier propagation environment is used as the demodulation quality of the medium. Incidentally, it is known that a recording medium such as an optical disc has different error rates near the center and the circumference. Therefore, in the present embodiment, the portions having different error rates such as the vicinity of the central portion and the periphery of the optical disc or the like are set as a plurality of media for recording data, and the error rate of the recording medium of each portion is set to each medium. The present invention can also be applied when used as demodulation quality.

(Embodiment 2)
FIG. 4 is a block diagram showing a configuration of a transmission apparatus according to Embodiment 2 of the present invention. In the transmission apparatus 300 according to the present embodiment in FIG. 4, the same reference numerals as those in FIG. 4 employs a configuration in which a divided block length determination unit 301 is added to FIG.

  The division block length determination unit 301 determines the number of information data to be allocated to each carrier, that is, the division block length, from the propagation environment information output from the propagation environment information extraction unit 107 according to the propagation environment of each carrier. For example, when the BER of a certain carrier is higher than a predetermined value and the propagation environment is poor compared to other carriers, the divided block length determination unit 301 assigns the number of information data to be assigned to a carrier with a poor propagation environment to the carrier with a good propagation environment. The divided block length is set to be shorter than the number of information data. As a result of setting the divided block length to be short, the number of information data allocated to a carrier having a poor propagation environment, that is, the number of target data that is highly likely to be affected by a transmission error is reduced. As a result, the ratio of receiving device side data errors due to transmission errors is reduced. Thereby, processing such as retransmission is reduced, and a reduction in transmission efficiency can be prevented. On the other hand, when the BER of a certain carrier is lower than a predetermined value and the propagation environment is better than that of other carriers, the divided block length determination unit 301 determines that the number of pieces of information data allocated to a carrier with a good propagation environment The divided block length is set to be longer than the number of information data allocated to the carrier. The divided block length determination unit 301 outputs the determined divided block length to the block division unit 102. Note that, as described above, the propagation environment information indicates the demodulation quality of the carrier when the carrier is used as a medium for transmitting data.

  Since the receiving apparatus according to Embodiment 2 has the same configuration as the receiving apparatus according to Embodiment 1, description thereof is omitted.

  Next, an operation for determining the divided block length and the coding rate by the transmission apparatus 300 configured as described above will be described below.

  The transmission apparatus 300 receives a signal including the propagation environment information notified from the reception apparatus 200 by the reception unit 106, and extracts the propagation environment information by the propagation environment information extraction unit 107.

  The extracted propagation environment information includes information such as carrier power-to-noise power ratio, signal power-to-noise power ratio, BER, and PER indicating the state of the propagation environment of each carrier. The data is output to block determination section 301 and coding rate determination section 108.

  When the propagation environment information is output to the divided block length determining unit 301, the divided block length determining unit 301 determines the number of information data allocated to each carrier, that is, the divided block length, according to the propagation environment of each carrier. The That is, when the BER of a certain carrier is higher than a predetermined value and the propagation environment is worse than that of other carriers, the divided block length is set short. As a result, the number of information data allocated to carriers with poor propagation environment is reduced, and as a result, the target data that is highly likely to be affected by transmission errors is reduced. In other words, the ratio of erroneous data on the receiving device side in response to a transmission error is reduced. As a result, processing such as retransmission is reduced, and a reduction in transmission efficiency can be prevented. The divided block length determined by the divided block length determining unit 301 is output to the block dividing unit 102.

  The propagation environment information is also output to coding rate determination section 108, and coding rate determination section 108 determines the coding rate corresponding to each carrier based on the propagation environment information of each carrier, as in the first embodiment. Is done. The determined coding rate is output to puncturing section 103.

  On the other hand, the information data is subjected to error correction coding processing in the coding unit 101, and a parity bit is added to the information data and output. The information data and the parity bit (data string) are divided by the block dividing unit 102 based on the divided block length determined by the divided block length determining unit 301. Here, the divided block length corresponding to each carrier is determined by the divided block length determination unit 301 based on the propagation environment of each carrier. That is, when the propagation environment of a certain carrier is worse than the propagation environment of another carrier, the division block length determination unit 301 is set so that the number of information data allocated to a carrier with a bad propagation environment is reduced. As a result, the number of target data that is highly likely to be affected by a transmission error is reduced, and the rate of erroneous data on the receiving device side in response to a transmission error is reduced. As a result, processing such as retransmission is reduced, and a reduction in transmission efficiency can be prevented.

  The divided data string, that is, the divided block is output to the puncturing unit 103, and the division divided by the block dividing unit 102 based on the coding rate determined by the coding rate determining unit 108 in the puncturing unit 103 Puncturing is performed for each block. Note that the coding rate used in puncturing is determined based on the propagation environment of each carrier by the coding rate determination unit 108, as in the first embodiment.

  The punctured divided blocks are allocated to a plurality of different carriers by the carrier dividing unit 104, and a multicarrier signal obtained by inverse Fourier transform is output to the transmitting unit 105. The multicarrier signal is transmitted through the antenna after being subjected to transmission processing (D / A conversion, orthogonal modulation, up-conversion to each carrier band, etc.) by the transmission unit 105.

  The multicarrier signal transmitted from the transmission device 300 is subjected to reception processing (down-conversion, demodulation, A / D conversion, etc.) by the reception unit 201 via the antenna of the reception device 200, and then divided into blocks in the depuncturing unit 202. Each block is depunctured, and is synthesized by the block synthesizing unit 203 into a data string before division, then decoded by the decoding unit 204, and output as information data to a device in a subsequent process.

  Next, a specific example of the puncturing operation in the second embodiment will be described with reference to FIG. In FIG. 5, each square represents a predetermined unit (bit, symbol, etc.) of data. FIG. 5 shows an example in which the encoding unit 101 functions as a 1-input 3-output encoder.

  As shown in FIG. 5A, the information data Xk (k: 1, 2,..., 36) is subjected to error correction coding processing in the coding unit 101, and the information data Xk is subjected to parity bits Zk, Z ′. k is added and output.

  Then, the information data Xk and the parity bits Zk and Z′k (data string) are divided by the block dividing unit 102 based on the divided block length determined by the divided block length determining unit 301. In FIG. 5B, the data sequence shown in FIG. 5A is divided by the block dividing unit 102 into four blocks surrounded by a thick frame based on the divided block length determined by the divided block length determining unit 301. Indicates the state. Here, FIG. 5B is an example of a case where the propagation environment of carrier 1 is worse than the other carrier 2, carrier 3, and carrier 4, and the divided block length determination unit 301 includes other carrier 2, carrier 3, The division block length was set so that the number of information data allocated to carrier 4 was 10, whereas the division block length was set so that the number of information data allocated to carrier 1 was 6 compared to other carriers. The situation is shown. By determining the divided block length so that the number of data allocated to the carrier 1 having a poor propagation environment is reduced, the number of target data that is highly likely to be affected by a transmission error is reduced. As a result, the rate of erroneous data on the receiving device side in response to a transmission error is reduced. As a result, processing such as retransmission is reduced, and a reduction in transmission efficiency can be prevented.

  The divided data string (FIG. 5B) is punctured for each divided block in the puncturing unit 103 based on the coding rate determined by the coding rate determining unit 108 (FIG. 5 ( c)). In FIG. 5C, hatched squares represent data deleted as a result of puncturing by the puncturing unit 103. Here, FIG. 5C is an example in which the propagation environment of carrier 1 is worse than the other carrier 2, carrier 3, and carrier 4, as in FIG. While the coding rate applied to the other carrier 2, carrier 3 and carrier 4 is set to 5/6, the coding rate applied to carrier 1 is set as low as 1/2. By setting the coding rate applied to the carrier 1 having a poor propagation environment to be low and improving the error correction effect, it is possible to prevent the error rate from being lowered due to the data string of the carrier 1, and the data on the receiving apparatus side The proportion of mistakes decreases. As a result, since processing such as retransmission is reduced, it is possible to improve the transmission efficiency of the entire data before division. The punctured data string is allocated to four different carriers in the carrier dividing unit 104, respectively.

  As described above, according to the present embodiment, the number of information data allocated to each carrier, that is, the divided block length and the coding rate corresponding to each carrier are set according to the propagation environment of each carrier. For this reason, the number of information data allocated to carriers with poor propagation environments, that is, the number of target data that is likely to be affected by transmission errors is reduced, and the error correction effect is improved for each carrier according to the carrier propagation environment. Therefore, transmission errors are reduced, the need for retransmission and the like is reduced, and the entire block before division can be efficiently transmitted.

  In the present embodiment, coding rate determination section 108 and divided block length determination section 301 independently determine the coding rate and divided block length, but coding rate determination section 108 determines divided block length. The coding rate of each block may be determined in consideration of the divided block length determined by the unit 301.

  In the present embodiment, a case has been described in which a carrier is used as a medium for transmitting data, and a carrier propagation environment is used as the demodulation quality of the medium. Incidentally, it is known that a recording medium such as an optical disc has different error rates near the center and the circumference. Therefore, in the present embodiment, the portions having different error rates such as the vicinity of the central portion and the periphery of the optical disc or the like are set as a plurality of media for recording data, and the error rate of the recording medium of each portion is set to each medium. The present invention can also be applied when used as demodulation quality.

(Embodiment 3)
FIG.6 is a block diagram showing the configuration of the transmission apparatus according to Embodiment 3 of the present invention. In the transmitting apparatus 400 of the present embodiment in FIG. 6, the same reference numerals as those in FIG. 6 employs a configuration in which the coding rate determination unit 108 is deleted and a divided block length / coding rate determination unit 401 is added to FIG.

  The division block length / coding rate determination unit 401 uses the propagation environment information output from the propagation environment information extraction unit 107 according to the propagation environment of each carrier in the same manner as the division block length determination unit 301 of the second embodiment. The number of information data allocated to each carrier, that is, the divided block length is determined. That is, the division block length is set to be short so that the number of information data allocated to a carrier with a poor propagation environment is smaller than the number of information data allocated to a carrier with a good propagation environment. Further, the divided block length / coding rate determining unit 401 is configured so that the number of transmission data obtained by adding the information data and the parity bit after puncturing for each divided block is the same in any divided block. The coding rate for each divided block is determined. At this time, when the coding rate at which the number of transmission data is the same in all the divided blocks cannot be calculated, the divided block length / coding rate determining unit 401 changes the divided block length to the changed divided block length. Based on this, the above-described procedure is repeated, and a combination of a divided block length and a coding rate that makes the same number of transmission data after puncturing is determined for each divided block. Divided block length / coding rate determining section 401 outputs the determined divided block length to block dividing section 102 and the determined coding rate to puncturing section 103. Note that, as described above, the propagation environment information indicates the demodulation quality of the carrier when the carrier is used as a medium for transmitting data.

  Since the receiving apparatus according to Embodiment 3 has the same configuration as the receiving apparatus according to Embodiment 1, description thereof is omitted.

  Next, an operation of determining the divided block length and the coding rate by the transmission apparatus 400 configured as described above will be described below.

  The transmission apparatus 400 receives a signal including the propagation environment information notified from the reception apparatus 200 by the reception unit 106, and extracts the propagation environment information by the propagation environment information extraction unit 107.

  The extracted propagation environment information includes information such as carrier power-to-noise power ratio, signal power-to-noise power ratio, BER, and PER indicating the state of the propagation environment of each carrier. It is output to the block length / coding rate determination unit 401.

  When the propagation environment information is output to the divided block length / coding rate determining unit 401, the divided block length / coding rate determining unit 401 firstly determines the divided block length according to the propagation environment of each carrier as described above. Is determined. That is, the division block length / coding rate determination unit 401 determines the division block length so that the number of information data allocated to a carrier with a good propagation environment is large and the number of information data allocated to a carrier with a poor propagation environment is small. .

  Further, based on the determined divided block length, the divided block length / coding rate determining unit 401 performs the same for each divided block so that the number of transmission data after puncturing for each divided block is the same. The coding rate is determined. At this time, when the coding rate in which the number of transmission data for each divided block is the same cannot be calculated, the divided block length is changed in the divided block length / coding rate determination unit 401, and then the changed divided block The above-described procedure is repeated based on the length, and the combination of the divided block length and the coding rate is determined so that the number of transmission data after puncturing is the same. In the calculation of the combination of the divided block length and the coding rate described above, since the number of information data to be allocated is small for a carrier having a poor propagation environment, in order to make it the same as the number of transmission data allocated to other carriers, information It is necessary to compensate for the small amount of data with parity bits. Therefore, the ratio of the number of parity bits deleted by puncturing is small compared to other carriers, and as a result, the coding rate corresponding to a carrier with a poor propagation environment is set low. In other words, the number of target data that is not likely to be received normally due to the influence of transmission errors is small, and the coding rate corresponding to a carrier with a poor propagation environment is set low. The effect can be improved. As a result, transmission errors are reduced, and as a result, processing such as retransmission is reduced, and transmission efficiency can be improved as the entire data before division. Furthermore, since the number of transmission data after puncturing is the same for each divided block, it can be applied to a system that complies with a communication protocol in which the number of transmission data for each carrier is limited to a specific size. It becomes. The divided block length determined by the divided block length / coding rate determining unit 401 is output to the block dividing unit 102, and the determined coding rate is output to the puncturing unit 103.

  On the other hand, the information data is subjected to error correction coding processing in the coding unit 101, and a parity bit is added to the information data and output. The information data and the parity bit (data string) are divided by the block dividing unit 102 based on the divided block length determined by the divided block length / coding rate determining unit 401. At this time, as described above, the divided block length used by the block dividing unit 102 is the same as the number of transmission data for each divided block after puncturing of each carrier by the divided block length / coding rate determining unit 401. To be determined. That is, in the divided block length / coding rate determining unit 401, when the propagation environment of a certain carrier is worse than that of another carrier, a divided block length as short as possible is set as compared with the divided block length corresponding to the other carrier. . In order for the number of transmission data after being punctured for each divided block to be the same, it is necessary to compensate for a small amount of information data with a parity bit in a divided block with a short divided block length. That is, when the divided block length is shorter than the other divided block lengths, the proportion of parity bits deleted by puncturing is smaller than other divided blocks. That is, when the divided block length is short, the corresponding coding rate is set low. As a result, the number of target data that is highly likely to be affected by transmission errors is reduced, and as a result of the low coding rate corresponding to carriers with poor propagation environment, the effect of carrier error correction is improved, The rate of data error on the receiving device side in response to a transmission error is reduced. As a result, processing such as retransmission is reduced, and a reduction in transmission efficiency can be prevented.

  The divided data string, that is, the divided block is output to the puncturing unit 103, and is divided for each divided block based on the coding rate determined by the divided block length / coding rate determining unit 401 in the puncturing unit 103. Punctured. At this time, as described above, the coding rate used by the puncturing section 103 is such that the number of transmission data after puncturing is the same by the divided block length / coding rate determining section 401. It is determined. That is, in the carrier having a poor propagation environment, the rate at which the parity bits are deleted is smaller than in other carriers. In other words, the coding rate corresponding to a carrier with a poor propagation environment is set low. As a result, the effect of error correction of the carrier set with a low coding rate is improved. As a result, transmission errors in a carrier having a poor propagation environment are reduced, processing such as retransmission is reduced, and deterioration in transmission efficiency can be prevented. In addition, since the number of transmission data after puncturing assigned to each carrier is the same, it can be applied to a system that complies with a communication protocol in which the number of transmission data is limited to a specific size. Become.

  The punctured data sequence is assigned to a plurality of different carriers by the carrier dividing unit 104, and a multicarrier signal obtained by inverse Fourier transform is output to the transmitting unit 105. The multicarrier signal is transmitted through the antenna after being subjected to transmission processing (D / A conversion, orthogonal modulation, up-conversion to each carrier band, etc.) by the transmission unit 105.

  The multicarrier signal transmitted from the transmission device 400 is subjected to reception processing (down-conversion, demodulation, A / D conversion, etc.) by the reception unit 201 via the antenna of the reception device 200, and then divided into blocks in the depuncturing unit 202. Each block is depunctured, and is synthesized by the block synthesizing unit 203 into a data string before division, then decoded by the decoding unit 204, and output as information data to a device in a subsequent process.

  Next, a specific example of the puncturing operation in the third embodiment will be described again with reference to FIG. In FIG. 5, each square represents a predetermined unit (bit, symbol, etc.) of data. FIG. 5 shows an example in which the encoding unit 101 functions as a 1-input 3-output encoder.

  As shown in FIG. 5A, the information data Xk (k: 1, 2,..., 36) is subjected to error correction coding processing in the coding unit 101, and the information data Xk is subjected to parity bits Zk, Z ′. k is added and output.

  Then, the information data Xk and the parity bits Zk and Z′k (data string) are divided by the block dividing unit 102 based on the divided block length determined by the divided block length / coding rate determining unit 401. FIG. 5B shows a state in which the data division is divided into four blocks surrounded by a thick frame in the block dividing unit 102 based on the divided block length determined by the divided block length / coding rate determining unit 401. Show. Then, the divided data string (FIG. 5B) is punctured for each divided block by the puncturing unit 103 based on the coding rate determined by the divided block length / coding rate determining unit 401. Is done. In FIG. 5C, hatched squares represent data deleted as a result of puncturing by the puncturing unit 103.

  Here, as described above, the divided block length / coding rate determining unit 401 determines the divided block length so that the number of data allocated to a carrier having a poor propagation environment is as small as possible. That is, the division block length / coding rate determination unit 401 determines the division block length so that the number of information data allocated to a carrier with a good propagation environment is large and the number of information data allocated to a carrier with a poor propagation environment is small. . Further, based on the determined divided block length, the divided block length / coding rate determining unit 401 performs the same for each divided block so that the number of transmission data after puncturing for each divided block is the same. The coding rate is determined.

  FIG. 5B shows an example in which the propagation environment of carrier 1 is worse than that of other carriers 2, 3, and 4, and the divided block length / coding rate determination unit 401 The division block length is set so that the number of information data assigned to carrier 4 is 10, whereas the number of information data assigned to carrier 1 is set to 6 and smaller than other carriers. The situation is shown below. 5C corresponds to each divided block so that the number of transmission data after puncturing is 12 with respect to the divided block determined by the divided block length / coding rate determining unit 401. The state in which the coding rate is set to {1/2, 5/6, 5/6, 5/6} is shown.

  In this way, by determining the divided block length so that the number of data allocated to a carrier having a poor propagation environment is reduced, the number of target data that is highly likely to be affected by a transmission error is reduced. In addition, since the number of information data to be allocated is small for a carrier having a poor propagation environment, it is necessary to compensate for the small amount of information data with a parity bit in order to make it the same as the number of transmission data allocated to other carriers. Therefore, in a divided block corresponding to a carrier having a poor propagation environment, the proportion of the number of parity bits deleted by puncturing is smaller than that of other carriers, and as a result, the corresponding coding rate is set low. In other words, the number of target data that is highly likely to be affected by transmission errors is set low, and the coding rate corresponding to carriers with poor propagation environment is set low, which improves the error correction effect of the corresponding carriers can do.

  In the example described above, an example in which the number of transmission data after puncturing is the same is shown. However, when the number of transmission data after puncturing is different, the division block length / coding rate determination unit 401 performs division. The block length is changed, and the procedure for calculating the coding rate with the same number of transmission data after puncturing is repeated based on the changed divided block length. The punctured data string is allocated to four different carriers in the carrier dividing unit 104, respectively.

  As described above, according to the present embodiment, the propagation environment information is set so that the number of transmission data obtained by summing the parity data and the information data after puncturing for each divided block is the same in any divided block. The combination of the divided block length and the corresponding coding rate is determined according to the above. As a result, the number of target data that is likely to be affected by transmission errors is reduced, and the coding rate corresponding to a carrier with a poor propagation environment is set low. The effect of error correction is improved. As a result, processing such as retransmission due to a transmission error is reduced, the entire data before division can be efficiently transmitted, and the number of transmission data for each carrier conforms to a communication protocol that is limited to a specific size. Can be applied to the system.

  In the communication system, a system-specific coding rate may be defined for data before division. Even in this case, the divided block length / coding rate determination unit 401 considers the system-specific coding rate defined for the data before division, and the divided block length and coding rate corresponding to each carrier. Can also be calculated. For example, it is assumed that 3/4 is defined as a system-specific coding rate for data before division. In this case, as shown in FIG. 5C, the division block length is determined so that the number of information data is {6, 10, 10, 10}, and the coding rate for the division block is {1/2, 5 / By setting it to 6, 5/6, 5/6}, a coding rate of 3/4 can be realized for the entire data before division. Specifically, when the coding rate {1/2, 5/6, 5/6, 5/6} is applied to each divided block with respect to the total number of information data 36 (= 6 + 10 + 10 + 10) allocated to each carrier. Since the total number of transmission data is 48 (= 12 + 12 + 12 + 12), the coding rate for the entire data before division is 3/4 (= 36/48), which is the same as the system-specific coding rate. Can do.

  The coding rate for the entire data before division is stored in advance by the divided block length / coding rate determination unit 401 as a system-specific coding rate, or is received by the receiving unit 106 by receiving information about the coding rate. By adopting such a method, it is possible to cope with a case where the coding rate for the data before division is variable.

  Thus, in determining the combination of the division block length and the coding rate described above, the division block corresponding to each carrier is determined according to the propagation environment of each carrier while considering the coding rate for the entire data before division. Set the combination of length and code rate. That is, the number of data allocated to a carrier having a poor propagation environment, that is, the number of target data that is highly likely to be affected by transmission errors is as small as possible, and the coding rate for the entire data before division becomes a desired value. A combination of a divided block length and a coding rate corresponding to the carrier is determined. Thereby, transmission errors are reduced, and as a result, processing such as retransmission is reduced, and the entire data before division can be transmitted efficiently. It is also possible to match the coding rate specific to the system.

  In the present embodiment, a case has been described in which a carrier is used as a medium for transmitting data, and a carrier propagation environment is used as the demodulation quality of the medium. Incidentally, it is known that a recording medium such as an optical disc has different error rates near the center and the circumference. Therefore, in the present embodiment, the portions having different error rates such as the vicinity of the central portion and the periphery of the optical disc or the like are set as a plurality of media for recording data, and the error rate of the recording medium of each portion is set to each medium. The present invention can also be applied when used as demodulation quality.

  An encoding apparatus according to a first aspect of the present invention is an encoding apparatus that assigns information data and a parity bit added to the information data to each of a plurality of media that transmit or record data. Coding rate determining means for determining a coding rate for each medium in accordance with the demodulation quality of the medium, and puncturing means for thinning out the parity bits added to the information data at the coding rate for each medium determined And allocating means for allocating the information data and the punctured parity bit to each of the plurality of media.

  According to this configuration, the coding rate for each medium is determined in accordance with the demodulation quality of each medium of the plurality of media that transmit or record data, and the parity bit to be added to the information data is determined for each medium. Puncturing is performed at a coding rate, and information data and parity bits after puncturing are assigned to each of a plurality of media. Therefore, even if the demodulation quality of each medium is different, the effect of error correction is different for each medium. It becomes possible to improve. Therefore, data can be efficiently encoded in a multi-carrier communication system, an optical disk, or the like. The same error correction code can be used for a plurality of media.

  The coding apparatus according to a second aspect of the present invention is the coding apparatus according to the first aspect, wherein the coding rate determining means determines the coding rate of a medium whose demodulation quality is worse than that of the other medium. The configuration is set to be lower than the coding rate.

  According to this configuration, since the coding rate corresponding to a medium whose demodulation quality is poorer than other media is set low, the number of parity bits to be thinned out is small. Therefore, it is possible to improve the error correction effect of a medium set with a low coding rate.

  The encoding apparatus according to a third aspect of the present invention, in the first aspect, provides a divided block length determining means for determining the length of a divided block as a unit for performing puncturing according to the demodulation quality of each medium. The structure which has these further is taken.

  According to this configuration, in order to determine the length of the divided block as a unit for performing puncturing according to the demodulation quality of each medium, the number of information data to be allocated to each medium is set according to the demodulation quality of each medium. It becomes possible.

  The encoding device according to a fourth aspect of the present invention is the encoding device according to the third aspect, wherein the divided block length determining means determines the length of the divided block corresponding to a medium whose demodulation quality is worse than that of the other medium. A configuration is adopted in which the length is set shorter than the length of the divided block corresponding to another medium.

  According to this configuration, since the divided block length corresponding to a medium having a poor demodulation quality compared to other media is set to be short, the number of information data allocated to a medium having a poor propagation environment can be reduced. Therefore, it is possible to reduce the number of target data that is highly likely to be affected by an error, thereby reducing the rate at which data is erroneous on the side of the decoding device in response to an error.

  The encoding apparatus according to a fifth aspect of the present invention is the encoding apparatus according to the third aspect, wherein the coding rate determining means makes the total number of information data and punctured parity bits included in each divided block the same. A configuration for determining the coding rate for each medium is adopted.

  According to this configuration, in order to determine the coding rate for each medium in which the total number of parity data after puncturing is the same as the information data included in each divided block, the number of information data for each medium and the parity after puncturing The present invention can be applied to a system that complies with a communication protocol in which the total number of bits is limited to a specific size. In addition, since the coding rate of a medium in which the divided block length is set short is set low, it is possible to improve the error correction effect of a medium having a poor propagation environment.

  The encoding apparatus according to a sixth aspect of the present invention is the encoding apparatus according to the first aspect, wherein the encoding rate determining means is configured to match the encoding rate of the entire plurality of media with a predetermined value for each medium. A configuration for determining the coding rate is adopted.

  According to this configuration, in order to determine the coding rate for each medium for matching the coding rate of the entire plurality of media with a predetermined value, the system-specific coding rate defined for the entire plurality of media. And can be consistent.

  According to a seventh aspect of the present invention, in the first aspect, the coding rate determining means adopts a configuration in which the coding rate is determined for each medium according to the error rate of each medium.

  According to this configuration, since the coding rate for each medium is determined in accordance with the error rate of each medium, it is possible to improve the error correction effect for each medium even when the error rate differs for each medium. Become.

  The decoding apparatus according to the eighth aspect of the present invention performs depuncturing to compensate for parity bits at a coding rate for each medium determined according to demodulation quality of a plurality of media transmitting or recording data. A configuration having puncturing means is adopted.

  According to this configuration, since depuncturing is performed to compensate for parity bits at a coding rate for each medium determined according to the demodulation quality of a plurality of media that transmit or record data, the effect of error correction for each medium Can be improved.

  The transmission apparatus according to the ninth aspect of the present invention includes an acquisition unit configured to acquire propagation environment information indicating a propagation state of a plurality of carriers, and sets a coding rate for each carrier according to the acquired propagation environment information of each carrier. Coding rate determining means for determining, puncturing means for performing puncturing to thin out the parity bits added by error correction coding of the information data at the coding rate for each determined carrier, and information data and post-puncturing And a transmission means for allocating and transmitting parity bits to each carrier.

  According to this configuration, puncturing is performed by thinning out parity bits added by error correction encoding of information data at a coding rate determined according to the propagation environment information of each carrier, and the information data and the parity after puncturing are performed. Since bits are assigned to each carrier for transmission, even if the propagation environment for each carrier is different, the effect of error correction can be improved for each carrier. Therefore, in the multicarrier communication system, processing such as retransmission can be avoided and data can be transmitted efficiently.

  A receiving apparatus according to a tenth aspect of the present invention includes a receiving means for receiving a signal in which information data and parity bits are assigned to a plurality of carriers, and coding for each carrier determined in accordance with the carrier propagation environment. And a depuncturing means for performing depuncturing to compensate the parity bit at a rate.

  According to this configuration, since the parity bits are compensated at the coding rate for each carrier determined according to the carrier propagation environment, it is possible to improve the error correction effect for each carrier. Therefore, in a multicarrier communication system, processing such as retransmission can be avoided and data transmission efficiency can be improved.

  An encoding method according to an eleventh aspect of the present invention is an encoding method for allocating information data and parity bits added to the information data to each of a plurality of media transmitting or recording data, Determining a coding rate for each medium according to the demodulation quality of the medium, performing puncturing to thin out the parity bits added to the information data at the determined coding rate for each medium, information data and puncturing And a step of assigning a parity bit after charing to each of the plurality of media.

  According to this method, the coding rate for each medium is determined according to the demodulation quality of each medium of a plurality of media for transmitting or recording data, and the parity bit added to the information data is determined for each medium. Puncturing is performed at a coding rate, and information data and parity bits after puncturing are assigned to each of a plurality of media, so even if the demodulation quality of each media is different, the effect of error correction can be improved for each media. It becomes possible to improve. Therefore, data can be efficiently encoded in a multi-carrier communication system, an optical disk, or the like. The same error correction code can be used for a plurality of media.

  The transmission apparatus of the present invention can avoid retransmission and the like and efficiently transmit data in a multicarrier communication system, and is particularly suitable for use in a transmission apparatus that uses an error correction code.

The block diagram which shows the structure of the transmitter which concerns on Embodiment 1 of this invention. FIG. 2 is a block diagram illustrating a configuration of a receiving apparatus according to Embodiment 1. (A) Conceptual diagram showing a data sequence after correction coding according to the first embodiment (b) Conceptual diagram showing a data sequence divided into a plurality of blocks according to the first embodiment (c) In the first embodiment Conceptual diagram showing the data sequence after puncturing The block diagram which shows the structure of the transmitter which concerns on Embodiment 2 of this invention. (A) Conceptual diagram showing a data sequence after correction coding according to the second and third embodiments. (B) A data sequence divided into a plurality of blocks according to the second and third embodiments. Conceptual diagram (c) Conceptual diagram showing a data string after puncturing according to the second and third embodiments The block diagram which shows the structure of the transmitter which concerns on Embodiment 3 of this invention. (A) Conceptual diagram showing data sequence after error correction coding (b) Conceptual diagram showing data sequence after puncturing (c) Conceptual diagram showing data sequence divided into a plurality of blocks

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Encoding part 102 Block division part 103 Puncturing part 104 Carrier division part 105 Transmission part 106 Reception part 107 Propagation environment information extraction part 108 Coding rate determination part 201 Reception part 202 Depuncturing part 203 Block composition part 204 Decoding part 205 Propagation environment information acquisition unit 206 Transmission unit 301 Division block length determination unit 401 Division block length / coding rate determination unit

Claims (11)

An encoding device that assigns information data and a parity bit added to the information data to each of a plurality of media for transmitting or recording data,
Coding rate determining means for determining a coding rate for each medium according to the demodulation quality of each medium;
Puncturing means for performing puncturing to thin out the parity bits added to the information data at a determined coding rate for each medium;
Allocating means for allocating information data and punctured parity bits to each of the plurality of media;
An encoding device comprising: The coding rate determining means includes
2. The encoding apparatus according to claim 1, wherein a coding rate of a medium having a lower demodulation quality than that of another medium is set to be lower than a coding rate of the other medium.   The encoding apparatus according to claim 1, further comprising divided block length determining means for determining a length of a divided block as a unit for performing puncturing according to a demodulation quality of each medium. The divided block length determining means includes
4. The encoding apparatus according to claim 3, wherein a length of a divided block corresponding to a medium whose demodulation quality is worse than that of another medium is set shorter than a length of a divided block corresponding to the other medium. . The coding rate determining means includes
4. The coding apparatus according to claim 3, wherein the coding rate for each medium is determined such that the total number of parity data after puncturing is the same as the information data contained in each divided block. The coding rate determining means includes
The encoding apparatus according to claim 1, wherein an encoding rate for each medium for determining the encoding rate of the plurality of media as a predetermined value is determined. The coding rate determining means includes
The encoding apparatus according to claim 1, wherein an encoding rate for each medium is determined according to an error rate of each medium. Depuncturing means for performing depuncturing to compensate parity bits at a coding rate for each medium determined according to demodulation quality of a plurality of media transmitting or recording data;
A decoding device characterized by comprising: Obtaining means for obtaining propagation environment information indicating propagation states of a plurality of carriers;
Coding rate determining means for determining a coding rate for each carrier according to the acquired propagation environment information of each carrier;
Puncturing means for performing puncturing to thin out the parity bits added by error correction encoding of information data at the determined coding rate for each carrier;
Transmitting means for allocating and transmitting information data and punctured parity bits to each carrier;
A transmission device comprising: Receiving means for receiving a signal in which information data and parity bits are assigned to a plurality of carriers;
Depuncturing means for performing depuncturing to compensate for parity bits at a coding rate for each carrier determined according to the carrier propagation environment;
A receiving apparatus comprising: An encoding method for assigning information data and a parity bit added to the information data to each of a plurality of media for transmitting or recording data,
Determining a coding rate for each medium according to the demodulation quality of each medium;
Puncturing the parity bits added to the information data at a coding rate for each determined medium;
Assigning information data and punctured parity bits to each of the plurality of media;
An encoding method characterized by comprising:

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