A code length adaptive polar encoding construction method

Abstract

The application discloses a code length adaptive parity check polar encoding construction method, which is based on a polarization channel, has a low front channel reliability, a high rear reliability and a serial decoding characteristic of a classical polarization decoding scheme SCL, and designs a polar encoding method based on channel reliability and inserting a specified parity check code number of the code length adaptively. The method comprises the following steps: firstly, a channel polarization weight value is obtained based on a Gaussian channel to measure the channel reliability, the polarization weight value is inverted and added to the maximum polarization weight value in the channel for conversion, and then the first insertion of PC code is performed at the position of half PC code number. Finally, the second insertion of PC code is performed based on the remaining PC code number, the information bit length of PC code check and the converted polarization weight value, so that the parity check code with the code length adaptivity and the front dense and rear sparse characteristics is constructed. When SCL decoding is performed at the decoding end, the effective distribution of the parity check code in the information bit is utilized to effectively improve the saving probability of the decoding correct branch and improve the decoding performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of channel coding, and relates to a coding method of a polar code in channel coding. BACKGROUND

[0002] The polar code (Polar) is generated from the channel polarization phenomenon, utilizes the combination and splitting idea of a symmetric binary input discrete memoryless channel, and is theoretically proved to be able to reach the Shannon limit and become a standard coding structure in modern communication. In the technology of 5G, the polar code is selected as the error correction coding standard for signaling transmission.

[0003] Since the code length of the polar code cannot tend to be infinite, the theoretical performance of the polar code strongly depends on the decoding algorithm of the polar code. The mainstream decoding algorithm at present is the SCL (Successive Cancellation List) decoding algorithm, but in the decoding process of the SCL, the path with the lowest path metric value in the decoding list is not necessarily the correct decoding result in the final output decision, therefore, scholars have proposed a cyclic redundancy check code auxiliary polar code (CRC-Polar code) to further improve the performance and effectively improve the decoding performance of the SCL.

[0004] The CRC-Polar code only performs the CRC code check on the final output decision, and in the decoding process of the SCL, when the number of paths reserved in the decoding list is greater than the decoding list, the pruning is only performed according to the path metric value, and the correct path may be pruned, in the decoding process of the SCL, other decoding methods such as the parity check code (PC code) can be combined to perform pruning, so as to improve the decoding performance of the CRC-Polar. In the polar code, the corresponding decoding is performed at the decoding end, and the corresponding coding method at the encoding end also needs to be changed. Meanwhile, the channel reliability obtained by polarizing the polar code is different, and the position insertion of the PC code is uniformly performed, which cannot well improve the decoding performance. In this case, a suitable PC code insertion method needs to be designed according to the reliability of the polar channel.

[0005] In summary, it is urgent to find a polar coding method of PC code insertion with adaptive code length according to the specified number of PC codes and the reliability of the polar channel. SUMMARY

[0006] In order to further improve the decoding performance of the CRC-Polar code, the application designs a PC code insertion coding method based on the specified number of PC codes and the reliability of the polar channel, and proposes a parity check polar coding construction method with adaptive code length to solve the problems in the prior art.

[0007] A code length adaptive polar encoding construction method, comprising the following steps:

[0008] S1, channel reliability estimation: selecting the code length N of the polar code, the code rate R and the Gaussian signal-to-noise ratio δ, calculating the polarization weight value of the polarized channel, the larger the polarization weight value, the higher the channel reliability, and vice versa; the polarization weight value is represented by YW i , initializing the transmission value of all transmission information as Si i =0, and i=1,2,...,N;

[0009] S2, determine the channel for transmitting total information bits: total information bits ST=K+P+C, wherein K is the number of information bits, P is the number of parity codes, and C is the length of CRC check code; select the ST channels with the highest channel polarization weight value as the channels for transmitting the total information bits, and arrange them in ascending order of channel index; the remaining N-ST channels transmit frozen bits, the information of the frozen bits is 0, and the set of transmission information bits is denoted as W F ;

[0010] S3, determine the transmission channel of the CRC check code: select C channels with the highest channel reliability from the ST channels as the transmission channel of the CRC check code, denoted as: W C ={W ST-c+1 ,W ST -c+2,...W ST};

[0011] S4, determine the transmission channel set of PC code and information bits: the transmission channel set of PC code is denoted as W P , and the transmission channel set of information bits is denoted as W K ;

[0012] S5, complete PC encoding based on information bits u, frozen bit information and PC code insertion position to obtain first encoding result u';

[0013] S6, CRC encoding and polar code encoding: using the generator matrix g(x) of the CRC check code to perform CRC encoding on the first N-C position data of the first encoding result u' to obtain the second encoding result u'', and finally performing polar code encoding on the second encoding result u'' to obtain the final encoding u'''.

[0014] Further, the determination of the channel for transmitting total information bits in step S2 specifically comprises:

[0015] First, sort the weight values of the channels based on the polarization weight values YW i , arrange them in ascending order, and assume that the channel sorting is WN = {W N1 N2 ,...,W Nn}, then YW N1 ≤ YW N2 ≤... ≤ YW Nn ; thus the last ST channels in W N are selected as the transmission channels of the total information bits, and the selected ST channels are arranged in ascending order of channel index, obtaining W = {W1, W2,..., W ST}, then index(W1) < index(W2) <... < index(W ST ), so that the check information bits of the PC code are all the preceding bits; wherein index(·) represents the index value of the channel; the remaining N-ST channels transmit frozen bits.

[0016] Further, the determination of the PC code and the transmission channel set of the information bits in step S4 specifically comprises:

[0017] Let W KP = {W1, W2,..., W ST-C} represent the channels transmitting the PC code and the information bits; the PC code channel set has two characteristics: uniform insertion channel set and proportional insertion channel set; wherein the first layer is the uniform insertion channel set, which is also the coarse insertion PC; the second layer is the proportional insertion channel set, which is also the fine insertion PC.

[0018] First layer: ST-C channels are divided by M times of average segmentation, wherein represents the floor operation; a PC code is inserted at the end of each segmentation, that is, a PC code is inserted every channels in the ST-C channels, that is, the first insertion position is the second position is until the end of the ST-C channels; let the obtained channel index set be W P1 = {W M , W 2M ,..., W ST-C};

[0019] Second layer: including the number of fine insertion blocks X and the proportional insertion operation of the quadratic PC in each block, specifically including (2.1) and (2.2) as follows:

[0020] (2.1) First determine the number of fine insertion blocks X

[0021] In each block of the first X blocks, Y is the information bit of the current block, then Y is the value closest to θ, wherein,​

[0022]

[0023] Therefore, the block of X satisfies,

[0024]

[0025] (2.2) Insertion of the second PC code for X blocks

[0026] The number of PC codes inserted in each X block is calculated by P A , then

[0027]

[0028] Therefore, the number of PC codes P A1 in the first inserted block is P A -M-P A , and the number of PC codes inserted in the following X-1 blocks is P B , and the sum of the transformed polarization weight values between the two PC code insertion positions in each X block accounts for the proportion of the entire block ψ,

[0029]

[0030] where P A1 = P B for the first block, and P A = P m for the following X-1 blocks, traverse the first X divided channel set, and insert a PC code at the position closest to ψ in the sum of the transformed polarization weight values of every s channels in the mth divided channel set. Assuming that the mth channel set is W m1 = {W m2 ,W mn ,...,W i}, the s position of the first inserted PC code satisfies:

[0031]

[0032] where HW i represents the transformed value after the maximum polarization weight value of the i-th channel polarization weight is negated and added, and HW i = (-YW A )+max(YW);

[0033] The remaining P P2 -1 PC code insertion positions are also calculated according to the first s position calculation formula, assuming that the channel index set obtained at this time is W m1W m2 W ms};

[0034] Thus, the final PC code insertion position channel set index W P = W P1 ∪ W P2 At this time, the number of element indexes in the set W P is P, and the remaining channels in W KP are used for information bit transmission, denoted as W K , that is, W K = W KP \ W P Here, W K = W KP \ W P represents removing the elements in the set W KP from the set W P to obtain the set W P .

[0035] Further, the step S5 specifically comprises:

[0036] The encoding formula of the ith PC check bit, that is, the ith parity check equation is:

[0037] Where i = 1, 2,..., P

[0038] Where, the set x i represents the index set of the information bits checked by the ith PC check bit, x i is determined by W K and W P , that is, the index set of x i is W P The channel index set of W K between two PC positions; u l represents the information bit value of the ith position, KP i represents the PC code value of the ith position; that is, the information bits checked by the ith PC check bit are summed and summed, and then mod 2 is taken, that is, the ith PC check bit value is obtained;

[0039] Then, based on the positions of the frozen bits W F , W P and W K and the information bits u, the values of the frozen bits KP i , the corresponding positions in Si are assigned in sequence, that is, the first encoding result u' is obtained.

[0040] The beneficial effects of the technical scheme of the present application are embodied in that uniform segmentation and PC code insertion of information bits cannot well improve decoding performance, while the flexible PC code insertion based on channel reliability designed by the present application can assist SCL decoding for pruning decision at the decoding end, thereby improving the decoding performance of CRC-SCL. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a flowchart of a code length adaptive polar encoding with parity check according to an embodiment of the present application;

[0042] Figure 2 is an example diagram of channel indexes corresponding to total information bits, wherein orange is the channel index of frozen bits, green is the channel index of PC bits, blue is the channel index of information bits, and yellow is the channel index of CRC check bits;

[0043] Figure 3 is a performance comparison diagram of PC-CRC-SCL and CRC-SCL. DETAILED DESCRIPTION

[0044] The present application will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are only used to illustrate the present application and not used to limit the scope of the present application. For those skilled in the art of the present application, several simple deductions or replacements can be made without departing from the concept of the present application, and all should be regarded as falling within the scope of the present application.

[0045] An embodiment of the present application provides a code length adaptive polar encoding construction method with parity check, referring to Figure 1 The method comprises the following steps S1-S6:

[0046] S1, channel reliability estimation based on GA (Gaussian Approximation). Specifically, the code length N, code rate R and Gaussian signal-to-noise ratio δ of the polar code are selected, and the polarization weight value of the polarized channel is calculated. The greater the polarization weight value, the higher the channel reliability, and vice versa. The polarization weight value is represented by YW i , and the transmission value of all transmission information is initialized as Si i (Note: the values in Si are all 0 at this time), and i = 1, 2,..., N.

[0047] S2, determine the channel of total information bit transmission. Specifically includes: total information bit ST=K+P+C, wherein K is the number of information bits, P is the number of parity check codes, and C is the length of CRC check code. Select ST(0 F .

[0048] Based on the polarization weight value YW i of the channel, sort the weight value of the channel in ascending order, and assume that the channel sorting is W N ={W N1 ,W N2 ,...,W Nn}, then YW N1 ≤YW N2 ≤...≤YW Nn ; therefore, select the last ST channels in W N as the channels for transmitting total information bits, and arrange the selected ST channels in ascending order of channel index to obtain W={W1,W2,...,W ST}, then index(W1)<index(W2)<....<index(W ST ), so that the check information bits of the PC code are all its preceding bits; wherein index(·) represents the index value of the channel; the remaining N-ST channels transmit frozen bits.

[0049] S3, determine the transmission channel of CRC check code. Select the C channels with the highest reliability among the ST channels as the transmission channel of CRC check code, denoted as: W C ={W ST-c+1 ,W ST -c+2,...W ST}.

[0050] S4: Determine the transmission channel set of PC code and information bits. The transmission channel set of PC code is denoted as W P , and the transmission channel set of information bits is denoted as W K .

[0051] denote W KP ={W1,W2,...,W ST-C}, which represents the channel for transmitting PC code and information bits; the PC code channel set has two characteristics: uniform insertion channel set and proportional insertion channel set; wherein the first layer is the uniform insertion channel set, which is also the coarse insertion PC; the second layer is the proportional insertion channel set, which is also the fine insertion PC;

[0052] First layer: M times average segmentation on ST-C channels, where denotes the floor operation; insert a PC code at the end of each segmentation, i.e. insert a PC code every channels in the ST-C channels, i.e. the first insertion position at this time is The second position is Until the end of the ST-C channels; record the channel index set obtained at this time as W P1 = {W M ,W 2M ,...,W ST-C};

[0053] Second layer: including the number of fine insertion blocks X and the quadratic PC according to the proportion insertion operation of each block, specifically including the following (2.1) and (2.2):

[0054] (2.1) First determine the number of fine insertion blocks X

[0055] In each of the first X blocks, Y is the information bits of the current block, then Y is the value closest to θ, where,

[0056]

[0057] θ is a data that can be set according to the actual situation during simulation, which is replaced by θ here, which can be adjusted according to the needs, and the value in the actual implementation case can be set to 15.

[0058] Therefore, the X blocks satisfy,

[0059]

[0060] (2.2) Insert the quadratic PC code for X blocks

[0061] Calculate the number of quadratic insertion PC codes in each X block, denoted by P A , then

[0062]

[0063] Therefore, the number of PC codes P A1 in the first inserted block is P A ·(X-1), and the number of quadratic insertion PC codes in the last X-1 blocks is P A , the sum of the polarization weight values transformed between the positions of the two PC codes inserted in each X block accounts for the proportion of the entire block ψ,

[0064]

[0065] where the first block of P B A1 and the last X-1 blocks of P B A In the first X segmented channel sets, the PC code is inserted at the position where the sum of the polarization weight values of every s channels in the mth segmented channel set is closest to ψ. Assuming that the mth channel set is W m m1 m2 mn The first inserted PC code s position satisfies:

[0066]

[0067] where HW i represents the transformed value of the i th channel polarization weight after the maximum polarization weight value is obtained by negating and adding, and HW i = (-YW i ) + max(YW) ;

[0068] The remaining P A -1 PC code insertion positions are also calculated according to the first s position calculation formula. Assuming that the channel index set obtained at this time is W P2 m1 m2 ms

[0069] Therefore, the final PC code insertion position channel set index W P = W P1 ∪ W P2 At this time, the number of element indexes in the W P set is P. The remaining channels in the W KP are used for information bit transmission, denoted as W K , that is, W K = W KP \ W P Here, W K = W KP \ W P represents removing the elements in the set W KP from the set W P to obtain the set W P .

[0070] S5, based on the information bits u, the frozen bit information and the PC code insertion position, PC encoding is completed to obtain a first encoding result u'.

[0071] ​​​​​​​​​The encoding formula of the ith PC check bit, i.e., the ith parity check equation is:

[0072] where i = 1, 2,..., P

[0073] where the set x i represents the index set of the information bits checked by the ith PC check bit, x i is determined by W K and W P , i.e., the index set of x i is W P The channel index set of W K between two PC positions; u l represents the information bit value of the lth position, KP i represents the PC code value of the ith position; i.e., the information bits checked by the ith PC check bit are summed and then modulo 2 is taken, i.e., the ith PC check bit value is obtained;

[0074] Then, based on the position set W F of the frozen bits, the positions of W P and W K and the information bits u, the values of the frozen bits KP i , the corresponding positions in Si are sequentially assigned, i.e., the first encoding result u' is obtained.

[0075] S6, CRC encoding and polar encoding. Specifically, the first N-C position data of u' are CRC encoded using the generator matrix g(x) of the CRC check code to obtain a second encoding result u", and finally u" is polar encoded to obtain a final encoding u'''.

[0076] A specific embodiment of a code length adaptive parity check polar encoding method includes the following steps:

[0077] Based on the initialized channel reliability information (polar weight value), HW i is obtained after conversion, and the transmission channels of the information bits, the CRC code word and the PC code are determined. Based on the information of the transmission channel, the information bits u are sequentially PC encoded, CRC encoded and polar encoded to complete the encoding. For example:

[0078] The channel polarization series of polar is N = 128, the length of the CRC code is 4, the number of PC codes is 8, the signal-to-noise ratio is -4, the value of θ is 15, the transmission code rate is 0.9, i.e., the total information bits ST = 108, and the information bit position to be transmitted is 96 bits.

[0079] Based on GA, the polarization of 128 channels is calculated to obtain the channel polarization value of 128 channels: YW, according to YW, the maximum polarization value of 108 channels is taken, and the remaining 20 channels are the transmission frozen bit value, and the channel set of the transmission frozen bit is as shown in the orange part of Figure 2 , and then the sorting of the channel index is performed, and the channel index set of the total information bit transmission:

[0080] W = {8,..., 48,..., 52,..., 90, 91, 92,..., 123, 124, 125, 126, 127, 128}

[0081] wherein the length of W is 108 bits, and the index value of the omitted channel set in W is displayed.

[0082] Therefore, the transmission channel of CRC: W C = {125, 126, 127, 128}, as shown in the yellow part of Figure 2 , then W KP = {8,..., 48,..., 52,..., 90, 91, 92,..., 123, 124}, and then the composition of W P is calculated:

[0083] (1) First layer: coarse insertion PC channel index W P1

[0084] First, 104 channels are divided by M times of average segmentation, at this time Therefore, the first insertion position of W P1 is the 26th channel index in W KP , the second insertion position is 52, and so on, and the last insertion position is the 104th channel position index in W KP , at this time W P1 = {37, 68, 98, 124}

[0085] (2) Second layer: fine insertion PC channel index W P2

[0086] (2.1) First, determine the block number X of secondary insertion based on δ, based on the formula

[0087]

[0088] The value of X is 2.

[0089] (2.2) X times of anti-block are inserted with secondary PC

[0090] In the last X-1 blocks, the number of secondary insertion PC

[0091]

[0092] Then the number of PC inserted in the first subblock is P A1 =2, so the proportion of the sum of the polar weight values of the transformed between two PC inserted positions in the whole subblock is ψ,

[0093]

[0094] So the sum of the polar weight values of the transformed between two PC inserted positions is 0.308 when the second fine insertion is performed, and the set of the inserted positions W P2 ={18,27,46,57} is obtained.

[0095] So the set of the position indexes of the PC code W P =W P1 ∪W P2 ={18,27,37,46,57,68,98,124}, as the green part in Figure 2 ; the remaining channel positions in W KP transmit information, as the blue part in Figure 2 . The PC position code value is calculated based on the information bits between each PC code, and the calculation formula is:

[0096] where i=1,2,...P

[0097] That is, the information bit value checked by the PC code is accumulated, and then the modulo 2 operation is performed to obtain the transmitted bit value of the PC code. Then the information bits are combined to obtain the PC code bit value. Finally, the PC code bit value is sequentially subjected to CRC encoding and polar encoding to obtain the final encoding value to be sent out.

[0098] Next, the code length adaptive parity check polar encoding is decoded, and the decoding bits are divided into two parts for decoding.

[0099] The first part: the position of the non-PC bit. When the decoding bit is the position of the non-PC bit, the decoding method is consistent with the SCL decoding method.

[0100] The second part: the position of the PC bit. Assuming that the i-th bit is a PC bit, i-1 bits have been decoded when decoding the PC bit, and the SCL decoding is performed on the PC bit. Then, according to the parity check operation of the first u i-1 bits of information, the following is obtained:

[0101]

[0102] where set xi denotes the index set of information bits checked by the ith PC check bit, consistent with the encoding end. denotes the information bit value of the ith position estimation, denotes the PC code value of the ith position estimation. The position decoding of PC bits is as follows:

[0103] Suppose the 27th position is the position of the PC bit, and one of the path estimation information bit values (including 5 bits) is [1, 0, 0, 1, 1, 1, 0, 0, 1], then,

[0104]

[0105] Therefore, at this time, the SCL decoding of the 27th position retains the position of the path with value 1. After all the decoding bits are completed, CRC checking is performed. The path value that can pass the CRC check is output, and if none of them passes the check, the path with the smallest PM value is output as the decoding output.

[0106] The code length adaptive parity check polar encoding method proposed in the present application is simulated and compared with the performance of CRC-polar encoding, and the simulation results are shown in the following Figure 3 . As can be seen from the simulation results in the following Figure 3 , when the FER reaches 10 -2 , the SNR of the encoding method (PC-CRC-SCL) proposed in the present application is about 3.9dB, while the SNR of the traditional CRC-SCL is about 4.2dB when the FER reaches 10 -2 , so the scheme proposed in the present application has a net gain of about 0.3dB when the FER is 10 -2 . Because the method of the present application combines the characteristics of the polar channel and the SCL decoding, the PC code is inserted at the sending end, and the effective distribution of the PC code is used at the receiving end to effectively improve the preservation probability of the correct decoding branch, thereby improving the decoding performance.

Claims

1. A method for constructing a code length adaptive parity check polar code, characterized in that: The steps include: S1. Channel reliability estimation: Select the code length N, code rate R and Gaussian signal-to-noise ratio δ of the polarization code, and calculate the polarization weight value of the polarized channel. The larger the polarization weight value, the higher the channel reliability, and vice versa. The polarization weight value is expressed in YW i Indicates that the transmission value of all transmission information is initialized to Si i =0, and i=1,2,...,N; S2. Determine the channels for total information bit transmission: total information bits ST = K + P + C, where K is the number of information bits, P is the number of parity check codes, and C is the length of the CRC check code; select ST channels with the highest channel polarization weight values ​​as the channels for total information bit transmission and arrange them in ascending order according to channel index; the remaining N-ST channels transmit frozen bits, and the information transmitted by the frozen bits is 0. The set of transmitted information bits is denoted as W F ; S3. Determine the transmission channel of the CRC check code: Select the C channels with the highest channel reliability among the ST channels as the transmission channel of the CRC check code, denoted as: W C ={W ST-c+1 ,W ST -c+2,...W ST }; S4. Determine the transmission channel set of the PC code and the information bit: the transmission channel set of the PC code is denoted as W P , the set of information bit transmission channels is recorded as W K ; S5. Complete PC coding based on the information bit u, the frozen bit information, and the insertion position of the PC code to obtain a first coding result u′; S6. CRC encoding and polar code encoding: Use the CRC check code generator matrix g(x) to perform CRC encoding on the first NC position data of the first coding result u′ to obtain a second coding result u″. Finally, perform polar code encoding on the second coding result u″ to obtain a final code u″′.

2. The parity check polar coding construction method as claimed in claim 1, wherein Determining the channel for transmitting the total information bits in step S2 specifically includes: First, based on the polarization weight value YW of the channel i Sort the channel weights in ascending order. Assume that the channel order is W N ={W N1 ,W N2 ,...,W Nn }, then YW N1 ≤YW N2 ≤...≤YW Nn ; Therefore, choose W N The last ST channels in the middle are used as the channels for transmitting the total information bits, and the selected ST channels are arranged in ascending order of channel index to obtain W = {W1, W2, ..., W ST }, then index(W1)<index(W2)<....<index(W ST ), so that the check information bits of the PC code are all its leading bits; where index(·) represents the index value of the channel; the remaining N-ST channels transmit frozen bits.

3. The parity check polar coding construction method as claimed in claim 1, wherein Determining the transmission channel set of the PC code and the information bit in step S4 specifically includes: Remember W KP ={W1,W2,...,W ST-C }, represents the channel for transmitting PC code and information bits; the PC code channel set has two layers of characteristics: uniform insertion channel set and proportional insertion channel set; the first layer is the uniform insertion channel set, also known as coarse insertion PC; the second layer is the proportional insertion channel set, also known as fine insertion PC; First layer: perform M equal divisions on ST-C channels, where Indicates the operation of rounding down; insert a PC code at the end of each division, that is, every ST-C channel The PC code is inserted into the channel, that is, the first insertion position is The second position is Until the end of ST-C channels; the channel index set obtained at this time is recorded as W P1 ={W M ,W 2M ,...,W ST-C }; The second layer: includes the number of finely inserted blocks X and the proportional insertion operation of the secondary PC of each block, which specifically includes the following (2.1) and (2.2): (2.1) First determine the number of blocks to be inserted X In each of the first X blocks, Y is the information bit of the current block, then Y is the value closest to θ, where Therefore, the partitioning of X satisfies, (2.2) Insert secondary PC code into X blocks Calculate the number of secondary inserted PC codes in each X block, using P A Indicates that Therefore, the number of PC codes P in the first inserted block is A1 =PMP A (X-1), in the next X-1 blocks, the number of PC codes inserted twice is P A , in each X block, the ratio of the sum of the polarization weight values ​​transformed between the positions where two PC codes are inserted to the entire block is ψ, Among them, the first block P B =P A1 , and then X-1 blocks of P B =P A , traverse the first X segmented channel sets, and in the m-th segmented channel set, insert a PC code at the position closest to the sum of the polarization weight values ​​of each s channel conversion. Assume that the m-th channel set is W m ={W m1 ,W m2 ,...,W mn }, then the s position of the first inserted PC code satisfies: Among them, HW i represents the transformed value of the polarization weight of the ith channel after negation and addition of the maximum polarization weight value, and HW i =(-YW i )+max(YW); The remaining P A -1 PC code insertion position is also calculated according to the first s position calculation formula, assuming that the channel index set obtained at this time is W P2 ={W m1 ,W m2 ,...,W ms }; Therefore, the channel set index W of the PC code insertion position is finally obtained P =W P1 ∪W P2 , at this time W P The number of element indexes in the collection is P, for W KP The remaining channels are used for the transmission of information bits, denoted as W K , that is, W K =W KP \W P , where W K =W KP \W P Represents the set W KP Remove the set W P The elements in the set W are obtained P .

4. The parity check polar coding construction method as claimed in claim 1, wherein Step S5 specifically includes: The encoding formula for the i-th PC check bit, that is, the i-th parity check equation is: where i = 1, 2, ... P Among them, the set x i represents the index set of information bits checked by the i-th PC check bit, x i By W K and W P OK, that is x i The index set is W P W between two PC positions K The channel index set of u l Indicates the information bit value of the lth position, KP i represents the PC code value of the ith position; that is, the information bits checked by the ith PC check bit are accumulated and summed, and then modulo 2 is performed to obtain the value of the ith PC check bit; Then based on the frozen bit position set W F 、W P and W K The position and information bit u, KP i , the value of the frozen bit is assigned to the corresponding position in Si in turn, and the first coding result u′ is obtained.

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