WO2021000531A1

WO2021000531A1 - Polar code segmented flipping decoding method based on llr, and intelligent terminal

Info

Publication number: WO2021000531A1
Application number: PCT/CN2019/126117
Authority: WO
Inventors: 何业军; 曹安琪; 张力
Original assignee: 深圳大学
Priority date: 2019-07-03
Filing date: 2019-12-18
Publication date: 2021-01-07
Also published as: CN110380819B; CN110380819A

Abstract

Disclosed are a polar code segmented flipping decoding method based on an LLR, and an intelligent terminal. The method comprises: calculating an LLR value of an information bit channel, performing statistics on index distribution of a low-reliability channel, and determining segmenting positions; performing segmented coding on an information sequence according to the segmenting positions, and then sending the information sequence to a transmission channel; performing SCL decoding on the received sequence, and performing a CRC in a segmented manner; performing bit flipping decoding on a sub-code segment that does not pass the CRC; and if the flipping decoding succeeds, continuing to decode the next segment or outputting a decoding result, and if the flipping decoding fails, terminating the decoding and declaring that the decoding has failed. According to the LLR-based segmented decoding in the present invention, multi-bit flipping decoding is realized, and the error correction success rate is improved; failed decoding is terminated in a timely manner, and calculation complexity is reduced; and a better decoding performance can be realized with lower calculation complexity.

Description

An LLR-based decoding method for segmented flipped polarization codes and intelligent terminal

Technical field

The present invention relates to the technical field of channel coding in a communication system, in particular to an LLR-based decoding method for segmented flipped polarization codes, an intelligent terminal and a storage medium.

Background technique

Polarization code is an emerging channel coding technology, and it is also the only coding scheme that can reach the Shannon limit in theory. Polarization codes are constructed on the theoretical basis of channel polarization. In the process of channel polarization, the channel capacity has shifted, some of the channel capacity becomes larger, and the other part of the channel capacity becomes smaller. When the code length tends to be infinite, some of the channel capacity is 1 and the other is 0. At this time, the low-complexity SC (successive cancellation) decoding algorithm can realize efficient and reliable transmission decoding. But for polarization codes with short and medium code lengths, not all channels are fully polarized, and the performance of the SC decoding algorithm is not ideal.

The SCL (SC list) algorithm improves decoding performance by retaining multiple possible decoding paths, and finally selects the most reliable decoding path for output. CA-SCL (CRC-aided SCL) uses cyclical redundancy check (CRC) codes to cascade polarized codes, sacrificing a certain code rate, and after SCL decoding, decode the reserved L bars The path uses CRC to select the best decoding path to output. The SCF (SC flip) algorithm tries to correct the wrong decoding with the help of bit flip and CRC check after the SC decoding is completed. These algorithms have greatly improved the decoding performance of polarization codes for short and medium code length decoding, but the cost is the increase in computational complexity and storage complexity.

The SCA-SCL (segmented CRC-aided SCL) algorithm divides the information bits into segments, and each segment is cascaded with CRC check bits, and each segment of decoding is completed to verify one segment of the decoding. If there is a decoding error, that is, no path can pass the CRC check, the decoding is terminated in time. The SCA-SCL decoding algorithm reduces the computational complexity and storage complexity, and does not lose the decoding performance of CA-SCL decoding, but the SCA-SCL decoding algorithm only performs error detection on the decoding result, but does not perform Error correction.

Therefore, the existing technology needs to be improved and developed.

Summary of the invention

The technical problem to be solved by the present invention is that the decoding performance of short and medium code length polarized codes is poor. In view of the above-mentioned defects in the prior art, the present invention provides a segmented flipped polarized code decoding method based on LLR, an intelligent terminal and storage medium.

The technical solutions adopted by the present invention to solve the technical problems are as follows:

An LLR-based segmented flipped polarization code decoding method, wherein the LLR-based segmented flipped polarization code decoding method includes:

Calculate the LLR value of the information bit channel, count the index distribution of the low-reliability channel, and determine the segment position;

Perform segmental coding on the information sequence according to the segment position and send it to the transmission channel;

Perform SCL decoding on the received sequence and perform CRC check in segments;

Perform bit inversion decoding on the sub-code segments that have not passed the CRC check;

If the flipping decoding is successful, continue to the next stage of decoding or output the decoding result, if the flipping decoding fails, then terminate the decoding and declare the decoding failure.

In the LLR-based segmented flipped polarization code decoding method, the steps of calculating the LLR value of the information bit channel, counting the index distribution of the low-reliability channel, and determining the segment position specifically include:

Calculating the LLR value of the information bit channel, where the LLR value is used to measure channel transmission reliability, and to make statistics on the index distribution of the low reliability channel;

The segment position is determined according to the index distribution of the low reliability channel, each segment is controlled to include a preset low reliability channel, and the last bit index of each segment is recorded.

In the LLR-based segmented flipped polarization code decoding method, the calculating the LLR value of the information bit channel and counting the index distribution of the low-reliability channel specifically includes:

For a polarization code with a code length of N=2 ⁿ and an information bit length of K, the input vector is

The decoder receiving vector is

The log likelihood ratio of the information bit, that is, the LLR value is:

among them,

Is the channel transmission probability. When the LLR value is used to measure channel transmission reliability, the larger |L(u _i )|, the higher the reliability; the statistically low-reliable channel index distribution means that the statistical LLR absolute value is small ；

The segment flip decoding algorithm with the number of segments P and the maximum number of flips per segment is T _max , there are P×T _max flip opportunities;

Repeatedly calculate the LLR value of the information bit channel for many times, and obtain the average distribution of |L(u _i )| by statistics, and obtain the index distribution of P×T _max low-reliability channels;

Define an unreliable set F, which consists of P×T _max with the smallest |L(u _i )| average

The index composition.

In the LLR-based segmented flipped polarization code decoding method, the step of performing segmental encoding on the information sequence according to the segment position and sending it to the transmission channel includes:

According to the segment position determined based on the LLR distribution, the last C bit of each segment is used as the CRC check bit, and C is the CRC code word length;

The K-P×C bit information sequence is divided into P segments, and each segment is cascaded with CRC for error detection. After the sub-code segments are combined, polarization coding is performed, and the polarization coding sequence is sent to the transmission channel.

In the LLR-based segmented flipped polarization code decoding method, the step of performing SCL decoding on the received sequence and performing CRC check in segments specifically includes:

Perform SCL decoding on the received sequence, and the decoding estimation vector is

Each decoding node reserves at most L decoding paths;

When the extended path is greater than L, the path is filtered according to the path metric value, and the L paths with the smallest metric value are retained. The path metric value PM:

L _l (u _i ) is the LLR value of the l- _th decoding path on channel i, and the LLR value is based on the estimated vector of path l

Calculation:

When SCL decoding reaches the end of each segment, CRC check is performed;

If there is a path that passes the CRC check, the path is reserved to continue to the next segment of decoding, if all sub-code segments are decoded, the path is output; if no path passes the CRC check, the sub-code that fails the CRC check Segments are decoded by bit flipping.

In the LLR-based segmented flipped polarization code decoding method, the step of performing bit flipped decoding on the sub-code segments that have not passed the CRC check includes:

Among the L decoding paths reserved after SCL decoding, a candidate path with the smallest path metric value is selected for single-bit inversion;

Define a flip set Flip, the set Flip is selected by the T _max of the decoding path with the smallest |L _l (u _i )| value

Index composition, and

Is in the sub-code segment that needs to be flipped and decoded;

When flipping decoding, arrange the |L _l (u _i )| values of the selected path in the corresponding index position of the segment in ascending order, and take the first T _max index with the smallest |L _l (u _i )| value to construct a flip set Flip ；

Select the bit corresponding to the first index from the set Flip to flip, and re-execute the SC decoding and CRC check on the bits after the segment starting from the bit corresponding to the index;

If the CRC check fails, restore the flip result and delete the index from the set Flip;

Select the bit corresponding to the second index to perform bit flip decoding again until the set Flip is empty.

In the LLR-based segmented flipped polarization code decoding method, wherein the step of performing bit flipped decoding on the sub-code segments that have not passed the CRC check further includes:

If the last index of the set Flip does not pass the CRC check after the bit flipping decoding is completed, it means that the flipping decoding has failed.

In the LLR-based segmented flipped polarization code decoding method, wherein, if the flipped decoding is successful, the step of continuing to the next stage of decoding or outputting the decoding result specifically includes:

If the reverse decoding is successful, the decoding path is retained to continue to perform SCL decoding on the next segment of codewords, and if the decoding of the information sequence is completed, the decoding path is output as the decoding result.

An intelligent terminal, wherein the intelligent terminal includes the above-mentioned LLR-based segmented flipped polarization code decoding system, and further includes: a memory, a processor, and a memory and a processor that are stored in the memory and can be stored in the processor LLR-based segmented inverted polarization code decoding program running on the LLR, when the LLR-based segmented inverted polarization code decoding program is executed by the processor, the above-mentioned LLR-based segmented inverted polarization is realized Steps of code decoding method.

A storage medium, wherein the storage medium stores an LLR-based segmented flipped polarization code decoding program, and the LLR-based segmented flipped polarization code decoding program is executed by a processor to achieve The steps of the LLR segmented flip polarization code decoding method.

The present invention performs LLR-based segmented flip decoding on polarized codes, aiming to improve the performance of polarized code CA-SCL decoding and reduce computational complexity. The present invention first calculates the LLR value and counts the low-reliability channel distribution, according to the LLR Distribute the polarization code segmented encoding and decoding to avoid low-reliability channels being densely distributed in a certain segment, increasing the probability of single-bit flipping success, and then using CRC check to perform single-bit flipping decoding on the sub-code segments with decoding errors. Decoding still makes an error when the number of flips reaches the threshold, and the decoding is terminated in time to reduce unnecessary decoding calculations. Since segment flipping increases the amount of decoding calculations at most N/P bits at a time, segment flipping decoding is relatively In traditional SCF decoding, there are more flipping opportunities, but it will not bring more computational complexity. The purpose of bit flipping decoding is to find and correct the first error bit in the decoding process, compared to the code length of N For polarized codes, it is easier to find the first error bit in the sub-code segment with a code length of N/P. In summary, the segment flipping decoding based on LLR can improve the decoding performance of polarized codes and reduce decoding calculations. the complexity.

Description of the drawings

Fig. 1 is a flowchart of a preferred embodiment of the LLR-based segmented flipped polarization code decoding method of the present invention;

Fig. 2 shows the information bit channel and the selection of the information bit channel when N=256, K=128, Eb/N0=1, and _Tmax =15 in the LLR-based segmented flip polarization code decoding method of the present invention. The standardized LLR average value of the bit channel in, the dotted line in the figure is the segment position when P=2;

3 is a schematic diagram of the LLR-based segmented inversion decoding process in the preferred embodiment of the LLR-based segmented inversion polarization code decoding method of the present invention;

Figure 4 is a performance comparison chart of the BLER (block error rate) between the LLR-based segmentation flipping decoding method and traditional SCF decoding, CA-SCL decoding, and SCA-SCL decoding of the present invention, where N=256, K=128 ,L=2;

Figure 5 is a comparison diagram of BLER performance between the LLR-based segmentation flipping decoding method and the CA-SCL decoding algorithm of the present invention, where the code length is N=256, K=128, and the maximum list size L=2,4,8,16 , The number of segments P=2;

Figure 6 is a comparison diagram of the average decoding list size of the LLR-based segmented flipping decoding algorithm and the CA-SCL decoding algorithm in the preferred embodiment of the LLR-based segmented flipping polarization code decoding method of the present invention, where the code Length N=256, K=128, maximum list size L=2, 4, 8, 16, and number of segments P=2;

Figure 7 is a schematic diagram of the operating environment of the preferred embodiment of the smart terminal of the present invention.

Detailed ways

In order to make the objectives, technical solutions, and advantages of the present invention clearer and clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

The LLR-based segmented flipped polarization code decoding method according to the preferred embodiment of the present invention, as shown in FIG. 1, an LLR-based segmented flipped polarization code decoding method, wherein the LLR-based The decoding method for segmented flipped polarization codes includes the following steps:

Step S10: Calculate the LLR value of the information bit channel, count the index distribution of the low-reliability channel, and determine the segment position.

Specifically, the LLR (Log Likelihood Ratio) value of the information bit channel is calculated, and the LLR value is used to measure the channel transmission reliability and count the index distribution of the low reliability channel; according to the low reliability The index distribution of the channel determines the segment position, each segment is controlled to include a preset low-reliability channel, and the last bit index of each segment is recorded.

The statistical code length is N=2 ⁿ , the information bit length is K polarization code, the input vector is

The decoder receiving vector is

The log likelihood ratio of the information bit, that is, the LLR value is:

among them,

It is the channel transmission probability. When the LLR value is used to measure the channel transmission reliability, the larger the |L(u _i )|, the higher the reliability; therefore, the index distribution of the statistically low-reliable channel is the channel index distribution with the small absolute value of the statistical LLR .

In order to determine the segment position, the method needs to count the |L(u _i )| value in advance to obtain an unreliable channel index set. The number of segments is P, and the maximum number of flips per segment is T _max . The segment flipping decoding algorithm has a total of P×T _max flipping opportunities; define an unreliable set F, and the set F has the smallest number of P×T _max |L (u _i )|valued

The LLR value of the information bit channel is calculated repeatedly for many times, and the average value distribution of |L(u _i )| can be obtained by statistics, and the index distribution of P×T _max low-reliability channels can be further obtained.

The segment position is determined according to the index distribution of the low-reliability channel, so that each segment contains T _max low-reliability channel indexes, and the end index of each segment is recorded at the same time; compared with the uniform segmentation method, the segmentation method makes unreliable estimation More evenly distributed in each sub-code segment.

Step S20: Perform segment coding on the information sequence according to the segment position and send it to the transmission channel.

Specifically, according to the segment position determined based on the LLR distribution, the last C bit of each segment is used as the CRC check bit, and C is the length of the CRC codeword; the KP×C bit information sequence is divided into P segments, and each segment is cascaded for CRC. For error detection, polarization coding is performed after combining the sub-code segments, and the polarization coding sequence is sent to the transmission channel.

Step S30: Perform SCL decoding on the received sequence, and perform CRC check in segments.

Specifically, SCL decoding is performed on the received sequence, and the decoding estimation vector is

Each decoding node reserves at most L decoding paths. When the extended path is greater than L, the path is filtered according to the path metric value, and the L paths with the smallest metric value are retained. Path metric PM:

L _l (u _i ) is the LLR value of the l- _th decoding path on channel i. LLR value according to the estimated vector of path l

Calculation:

When SCL decoding progresses to the end of each segment, a CRC check is performed. If there is a path that passes the CRC check, the path is retained to proceed to the next segment of decoding, if all sub-code segments are decoded, the path is output; if no path passes the CRC check, the segment is decoded by bit inversion.

Step S40: Perform bit inversion decoding on the sub-code segments that have not passed the CRC check.

Specifically, among the L decoding paths reserved after SCL decoding, a candidate path with the smallest path metric value is selected for single-bit flipping, and a flip set Flip is defined. The set Flip is composed of T _max of the selected decoding paths. With the smallest |L _l (u _i )| value

Index composition, and

It is in the sub-code segment that needs to be flipped and decoded. When flipping decoding, arrange the |L _l (u _i )| values of the selected path in the corresponding index position of the segment in ascending order, and take the first T _max index with the smallest |L _l (u _i )| value to construct a flip set Flip .

Select the bit corresponding to the first index from the set Flip to flip, and start from the bit corresponding to the index to perform SC decoding and CRC check again on the bits after the segment. If the CRC check fails, the flip result is restored, and the index is deleted from the set Flip. Select the bit corresponding to the second index to perform bit flip decoding again until the set Flip is empty. If the last index corresponding to the set Flip still fails to pass the CRC check after the bit flipping decoding is completed, the flipping decoding fails.

Step S50: If the flipping decoding is successful, continue to the next stage of decoding or output the decoding result, if the flipping decoding fails, then terminate the decoding and declare the decoding failure.

Specifically, if the flipping decoding is successful, the decoding path is reserved to continue to perform SCL decoding on the next segment of codewords. If the information sequence decoding is completely completed, the decoding path is output as the decoding result; if the flipping decoding fails, Then the decoding is terminated and the decoding is declared as a failure to reduce redundant decoding calculations.

The present invention will be further described in detail below in conjunction with the drawings and specific embodiments. It should be pointed out that the embodiments described below are intended to facilitate the understanding of the present invention, and do not have any limiting effect on it.

For example, the code length N=256, K=128, the polarization code carrying the information sequence

After encoding, channel transmission, receiving by the decoder, the receiving sequence is

The LLR-based segmented flip polarization code decoding method of the present invention has

Decoding, the decoding estimation vector is

The maximum number of flips in each segment T _max =15, the 8-bit and 16-bit CRC check generating polynomials used are:

CRC-8: g(x)=x ⁸ + x ⁷ + x ⁶ + x ⁴ + x ² +1;

CRC-16: g(x)=x ¹⁶ + x ¹⁵ + x ² +1;

Specific steps are as follows:

The first step: Calculate the LLR value of the polarization code channel with code length N=256 and K=128, count the index distribution of the low reliability channel, and determine the segment position. First calculate the average |L _l (u _i )| value of the information bit channel:

among them,

Is the channel transmission probability; then for the segment flipping decoding with the number of segments P=2 and the maximum number of flips per segment is T _max =15, there are a total of P×T _max =30 flipping opportunities. The unreliable set F consists of 30 with the smallest |L(u _i )|

The index composition. Calculate the LLR value of the information bit channel repeatedly for 10,000 times, obtain the average distribution of |L(u _i )| by statistics, and further select the index of 30 low-reliability channels (the channel with the smallest |L(u _i )|), as shown in the figure 2 shown. The segment position is determined according to the index distribution of the low-reliability channel. As shown by the dashed vertical line in Figure 2, the last bit index of the first segment is 49, so that each segment contains 15 low-reliability channel indexes. Compared with uniform segmentation, the LLR-based segmentation position is more advanced, and the low-reliability channel index is more evenly distributed in each segment, which is conducive to bit flipping decoding to successfully find the first error bit.

Step 2: According to the segment position determined based on the LLR distribution, the last 8 bits of each segment are used as CRC check bits, that is, CRC-8 is used as the generator polynomial. Divide K-P×8=112 information bits into 2 segments, each segment is concatenated with 8 CRC bits, and then the 2 segments are combined to perform polarization coding. Further, the encoded sequence is sent to the transmission channel.

The third step: LLR-based segment flipping decoding is performed on the received sequence. The decoding flow chart is shown in Figure 3. First, SCL decoding is performed on the received sequence, and each decoding node reserves at most L decoding paths. When the extended path is greater than L, the path is filtered according to the path metric value, and the L paths with the smallest metric value are retained. Path metric PM:

Calculation:

When SCL decoding progresses to the end of each segment, a CRC check is performed. If there is a path that passes the CRC check, the path is reserved to continue SCL decoding, and if all sequence decoding is completed, the path is output; if no path passes the CRC check, the segment is decoded by bit inversion. Among the L decoding paths reserved after SCL decoding, a candidate path with the smallest path metric value is selected for single-bit inversion. Arrange the |L _l (u _i )| values of the selected path at the corresponding index position of the segment in ascending order, and take the first 15 indexes with the smallest |L _l (u _i )| value to construct a flip set Flip. If the flipping decoding is successful, the decoding path is reserved to continue to perform SCL decoding on the next segment of codewords. If the information sequence decoding is completed, the decoding path is output as the decoding result; if the flipping decoding fails, the decoding is terminated. Code and declare the decoding failed.

Here draw the experimental simulation diagram with Block=10 ⁶ and Eb/N0=0.5～3. Fig. 4 is a comparison diagram of the BLER performance of the LLR-based segmented flip decoding method of the present invention and the traditional SCF decoding, CA-SCL decoding and SCA-SCL decoding. Here the number of segments P=2,4, and the list size L=2. The unsegmented SCF and CA-SCL decoding both use 16-bit CRC check bits, and the segmented SCA-SCL and the LLR-based segmented inversion decoding of the present invention both use 8-bit CRC check bits. As shown in the figure, the BLER performance of the LLR-based segmented flipping decoding of the present invention is significantly improved compared to the BLER performance of other traditional decoding methods, and the decoding performance of 4 segments is better than that of 2 segments. .

Fig. 5 is a comparison diagram of BLER performance between the LLR-based segmented flipping decoding method and the CA-SCL decoding method of the present invention under different maximum list sizes L, where P=2 and L=2,4,8,16. With the increase of L, the decoding performance of the two algorithms are improved, and the BLER performance of the LLR-based segmented flipping decoding method of the present invention is always better than that of the CA-SCL decoding method.

Since the calculation complexity of the list decoding method is proportional to the size of the decoding list, in the embodiment of the present invention, the average decoding list size is used to represent the decoding calculation complexity. In the embodiment of the present invention, the size of the decoding list for completing a segment flip decoding based on LLR is:

Where k is the number of decoded segments, if the decoding fails, k is the number of decoded segments when the decoding is terminated, otherwise k=P. F is the number of flipping decoding times, L _flip (j) is the size of the decoding list for the jth flipping decoding, L _flip (j)=number of bits for the jth flipping decoding/N.

Fig. 6 is a comparison diagram of the decoding average list size between the LLR-based segment flipping decoding method and the CA-SCL decoding method of the present invention under different maximum list sizes L, where P=2, L=2, 4, 8, 16. It can be seen that when L is greater than 8, the average decoding list size of the LLR-based segmentation flipping decoding method of the present invention will be smaller than the average decoding list size of the CA-SCL decoding method, that is, L. Therefore, compared with the traditional CA-SCL decoding method, the LLR-based segment flip decoding method of the present invention can achieve better BLER performance with lower decoding calculation complexity.

Further, as shown in FIG. 7, based on the above-mentioned LLR-based segmented flipped polarization code decoding method, the present invention also provides an intelligent terminal correspondingly. The intelligent terminal includes a processor 10, a memory 20, and a display 30. FIG. 7 only shows part of the components of the smart terminal, but it should be understood that it is not required to implement all the shown components, and more or fewer components may be implemented instead.

The memory 20 may be an internal storage unit of the smart terminal in some embodiments, such as a hard disk or memory of the smart terminal. In other embodiments, the memory 20 may also be an external storage device of the smart terminal, such as a plug-in hard disk equipped on the smart terminal, a smart media card (SMC), and a secure digital (Secure Digital). Digital, SD) card, flash card (Flash Card), etc. Further, the memory 20 may also include both an internal storage unit of the smart terminal and an external storage device. The memory 20 is used to store application software and various data installed on the smart terminal, such as program code for the smart terminal installed. The memory 20 can also be used to temporarily store data that has been output or will be output. In one embodiment, the LLR-based segmented flipped polarization code decoding program 40 is stored in the memory 20, and the LLR-based segmented flipped polarization code decoding program 40 can be executed by the processor 10, thereby realizing this The application is based on the LLR segmented flipped polarization code decoding method.

In some embodiments, the processor 10 may be a central processing unit (CPU), a microprocessor or other data processing chip, which is used to run the program code or process data stored in the memory 20, for example Perform the LLR-based segmented flipped polarization code decoding method and so on.

In some embodiments, the display 30 may be an LED display, a liquid crystal display, a touch liquid crystal display, an OLED (Organic Light-Emitting Diode, organic light-emitting diode) touch device, etc. The display 30 is used for displaying information on the smart terminal and for displaying a visualized user interface. The components 10-30 of the smart terminal communicate with each other via a system bus.

In an embodiment, when the processor 10 executes the LLR-based segmented flipped polarization code decoding program 40 in the memory 20, the following steps are implemented:

The present invention also provides a storage medium, wherein the storage medium stores an LLR-based segmented flipped polarization code decoding program, which is implemented when the LLR-based segmented flipped polarization code decoding program is executed by a processor The steps of the LLR-based segmented flipped polarization code decoding method; the details are as described above.

In summary, the present invention provides an LLR segmented flipped polarization code decoding method and an intelligent terminal. The method includes: calculating the LLR value of the information bit channel, counting the index distribution of the low reliability channel, and determining the segment Position; segment-encode the information sequence according to the segment position and send it to the transmission channel; perform SCL decoding on the received sequence and perform CRC check on the segment; perform bit-reversal decoding on sub-code segments that fail the CRC check; If the flipping decoding is successful, continue to the next stage of decoding or output the decoding result; if the flipping decoding fails, terminate the decoding and declare the decoding failed. The LLR-based segmentation of the present invention makes low-reliability bits more evenly distributed in each segment; segment flipping decoding realizes error correction in a shorter code segment, improves the probability of error correction success and realizes multi-bit flipping; When the decoding fails, the decoding is terminated in time to reduce the redundant decoding calculation complexity.

Of course, a person of ordinary skill in the art can understand that all or part of the processes in the method of the foregoing embodiments can be implemented by instructing relevant hardware (such as a processor, a controller, etc.) through a computer program, and the program can be stored in a computer program. In a computer-readable storage medium, the program may include the processes of the foregoing method embodiments when executed. The storage medium mentioned may be a memory, a magnetic disk, an optical disk, and the like.

It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or changes can be made based on the above description, and all these improvements and changes should fall within the protection scope of the appended claims of the present invention.

Claims

An LLR-based segmented flipped polarization code decoding method, characterized in that the LLR-based segmented flipped polarization code decoding method includes:

Calculate the LLR value of the information bit channel, count the index distribution of the low-reliability channel, and determine the segment position;

Perform segmental coding on the information sequence according to the segment position and send it to the transmission channel;

Perform SCL decoding on the received sequence and perform CRC check in segments;

Perform bit inversion decoding on the sub-code segments that have not passed the CRC check;

If the flipping decoding is successful, continue to the next stage of decoding or output the decoding result, if the flipping decoding fails, then terminate the decoding and declare the decoding failure.
The LLR-based segmented flipping polarization code decoding method according to claim 1, wherein the step of calculating the LLR value of the information bit channel, counting the index distribution of the low-reliability channel, and determining the segment position is specifically include:

Calculating the LLR value of the information bit channel, where the LLR value is used to measure channel transmission reliability, and to make statistics on the index distribution of the low reliability channel;

The segment position is determined according to the index distribution of the low reliability channel, each segment is controlled to include a preset low reliability channel, and the last bit index of each segment is recorded.
The LLR-based segmented flipped polarization code decoding method according to claim 1 or 2, wherein the calculating the LLR value of the information bit channel and counting the index distribution of the low reliability channel specifically includes:

For a polarization code with a code length of N=2 n and an information bit length of K, the input vector is
The decoder receiving vector is
The log likelihood ratio of the information bit, that is, the LLR value is:

among them,
Is the channel transmission probability. When the LLR value is used to measure channel transmission reliability, the larger |L(u i )|, the higher the reliability; the statistically low-reliable channel index distribution means that the statistical LLR absolute value is small ；

The segment flip decoding algorithm with the number of segments P and the maximum number of flips per segment is T max , there are P×T max flip opportunities;

Repeatedly calculate the LLR value of the information bit channel for many times, and obtain the average distribution of |L(u i )| by statistics, and obtain the index distribution of P×T max low-reliability channels;

Define an unreliable set F, which consists of P×T max with the smallest |L(u i )| average
The index composition.
The LLR-based segmented flipped polarization code decoding method according to claim 3, wherein the step of performing segmental encoding on the information sequence according to the segment position and sending it to the transmission channel comprises:

According to the segment position determined based on the LLR distribution, the last C bit of each segment is used as the CRC check bit, and C is the CRC code word length;

The K-P×C bit information sequence is divided into P segments, and each segment is cascaded with CRC for error detection. After the sub-code segments are combined, polarization coding is performed, and the polarization coding sequence is sent to the transmission channel.
The LLR-based segmented flipped polarization code decoding method according to claim 4, wherein the step of performing SCL decoding on the received sequence and performing CRC check in segments specifically includes:

Perform SCL decoding on the received sequence, and the decoding estimation vector is
Each decoding node reserves at most L decoding paths;

When the extended path is greater than L, the path is filtered according to the path metric value, and the L paths with the smallest metric value are retained. The path metric value PM:

L l (u i ) is the LLR value of the l- th decoding path on channel i, and the LLR value is based on the estimated vector of path l
Calculation:

When SCL decoding progresses to the end of each segment, CRC check is performed;

If there is a path that passes the CRC check, the path is reserved to continue to the next segment of decoding, if all sub-code segments are decoded, the path is output; if no path passes the CRC check, the sub-code that fails the CRC check Segments are decoded by bit flipping.
The LLR-based segmented flipped polarization code decoding method according to claim 5, characterized in that the step of performing bit flipping decoding on sub-code segments that have not passed the CRC check includes:

Among the L decoding paths reserved after SCL decoding, a candidate path with the smallest path metric value is selected for single-bit inversion;

Define a flip set Flip, set Flip from the selected decoding path T max has the smallest |L l (u i )| value
Index composition, and
Is in the sub-code segment that needs to be flipped and decoded;

When flipping decoding, arrange the |L l (u i )| values of the selected path in the corresponding index position of the segment in ascending order, and take the first T max index with the smallest |L l (u i )| value to construct a flip set Flip ；

Select the bit corresponding to the first index from the set Flip to flip, and re-execute the SC decoding and CRC check on the bits after the segment starting from the bit corresponding to the index;

If the CRC check fails, restore the flip result and delete the index from the set Flip;

Select the bit corresponding to the second index to perform bit flip decoding again until the set Flip is empty.
The LLR-based segmented inverted polarization code decoding method according to claim 6, wherein the step of performing bit inversion decoding on sub-code segments that have not passed the CRC check further comprises:

If the last index of the set Flip does not pass the CRC check after the bit flipping decoding is completed, it means that the flipping decoding has failed.
The LLR-based segmented flipped polarization code decoding method according to claim 6 or 7, characterized in that, if the flipped decoding is successful, the step of continuing to the next stage of decoding or outputting the decoding result specifically includes :

If the reverse decoding is successful, the decoding path is retained to continue to perform SCL decoding on the next segment of codewords, and if the information sequence decoding is completed, the decoding path is output as the decoding result.
An intelligent terminal, characterized in that, the intelligent terminal includes: a memory, a processor, and a segmented flipped polarization code decoding program based on LLR that is stored on the memory and can run on the processor, and When the LLR-based segmented flipped polarization code decoding program is executed by the processor, the steps of the LLR-based segmented flipped polarization code decoding method according to any one of claims 1-8 are realized.
A storage medium, characterized in that the storage medium stores an LLR-based segmented flipped polarization code decoding program, and when the LLR-based segmented flipped polarization code decoding program is executed by a processor, the The steps of the LLR-based segmented flipped polarization code decoding method described in any one of 1-8 are required.