Encoding method, decoding method, encoding device and decoding device for structured LDPC

A decoder for structured low density parity check codes (LDPC) applied in wireless digital communication system, comprising:

• a memory, configured to store at least an Mb×Nb basic matrix used for decoding, wherein the basic matrix comprises an Mb×(Nb−Mb) block A corresponding to systematic bits and an Mb×Mb block B corresponding to check bits, the basic matrix comprises K0 up-and-down adjacent pairs, the K0 up-and-down adjacent pairs comprise K1 up-and-down adjacent pairs of a first type and K2 up-and-down adjacent pairs of a second type, wherein K0=K1+K2, K0 is a positive integer greater than or equal to 6*Mb, K2 is a positive integer greater than or equal to 0 and less than or equal to 2*Mb, the up-and-down adjacent pairs are a set constituted by two elements {hbij, hb((i+1)mod Mb)j} in the basic matrix corresponding to non-zero square matrices,
• up-and-down adjacent pairs of the first type are up-and-down adjacent pairs that are congruential with (hbij−hb((i+1)mod Mb)j) mod Q=a, and
• up-and-down adjacent pairs of the second type are up-and-down adjacent pairs that are congruential with (hbij−hb((i+1)mod Mb)j) mod Q=b,
• wherein hbij represents an element in an ith row and jth column of the basic matrix, wherein a and b are not equal, a and b are integers greater than or equal to 0 and less than or equal to Q−1, Q is a multiplication factor of an expansion factor z, i is a row index of the basic matrix, j is a column index of the basic matrix, i=0, 1, . . . , Mb−1, j=0, 1, . . . , Nb−1;
• and
• a processor, configured to determine the basic matrix and a corresponding expansion factor z, and perform an LDPC decoding operation of obtaining information data of (Nb−Mb)×z bits based on a codeword of Nb×z bits, wherein z is a positive integer greater than or equal to 1;
• wherein
• Q=2, a=0, b=1.

A decoder for structured low density parity check codes (LDPC) applied in wireless digital communication system, comprising hardware performing instructions stored in a non-transitory computer readable medium which executes steps in following modules:

• a basic matrix storage module, configured to store at least an Mb×Nb basic matrix used for decoding, wherein the basic matrix comprises an Mb×(Nb−Mb) block A corresponding to systematic bits and an Mb×Mb block B corresponding to check bits, the basic matrix comprises K0 up-and-down adjacent pairs, the K0 up-and-down adjacent pairs comprise K1 up-and-down adjacent pairs of a first type and K2 up-and-down adjacent pairs of a second type, wherein K0=K1+K2, K0 is a positive integer greater than or equal to 6*Mb, K2 is a positive integer greater than or equal to 0 and less than or equal to 2*Mb, the up-and-down adjacent pairs are a set constituted by two elements {hbij, hb((i+1)mod Mb)j} in the basic matrix corresponding to non-zero square matrices,
• up-and-down adjacent pairs of the first type are up-and-down adjacent pairs that are congruential with (hbij−hb((i+1)mod Mb)j) mod Q=a, and
• up-and-down adjacent pairs of the second type are up-and-down adjacent pairs that are congruential with (hbij−hb((i+1)mod Mb)j) mod Q=b,
• wherein hbij represents an element in an ith row and jth column of the basic matrix, wherein a and b are not equal, a and b are integers greater than or equal to 0 and less than or equal to Q−1, Q is a multiplication factor of an expansion factor z, i is a row index of the basic matrix, j is a column index of the basic matrix, i=0, 1, . . . , Mb−1, j=0, 1, . . . , Nb−1;
• and
• a decoding operation module, configured to determine the basic matrix and a corresponding expansion factor z, and perform an LDPC decoding operation of obtaining information data of (Nb−Mb)×z bits based on a codeword of Nb×z bits, wherein z is a positive integer greater than or equal to 1;
• wherein
• Q=2, a=0, b=1.