Method for constructing checking matrix of ldpc code and coding and decoding apparatus utilizing the method

A method for constructing a low density parity check (LDPC) code check matrix, in the case that the constructed check matrix has dimensions of M×N, the method comprising the following steps:

• a step of obtaining a common factor set Fc of M and N;
• a step of selecting a proper extending ratio KεFc and generating a fundamental matrix with dimensions MB×NB using any manner, in which MB=M/K, NB=N/K;
• a step of extending the fundamental matrix by columns and constructing a MB×N matrix, the step comprising:
• for non-zero elements with row-column coordinate (m, n) in the fundamental matrix, selecting a set of column extending coefficients {ki, 0≦k≦K−1, iεZ+} which are different from each other, with “1” on positions (m, ki×NB+n) of the MB×N matrix, where the Z+ denotes the set of positive integers;
• and
• a step of extending K rows based on each row of the constructed MB×N matrix.

A method for constructing an LPDC check matrix, in the case that the constructed check matrix has dimensions of M×N, the method comprising the following steps:

• first step:
• obtaining a common factor set Fc of M and N;
• second step:
• selecting a proper extending ratio KεFc and generating a fundamental matrix with dimensions MB×NB using any manner, in which MB=M/K, NB=N/K;
• third step:
• extending the fundamental matrix by rows and constructing a M×NB matrix, the step comprising:
• for non-zero elements with row-column coordinate (m, n) in the fundamental matrix, and selecting a set of row extending coefficients {ki, 0≦ki≦K−1, iεZ+} which are different from each other, with “1” on positions (ki×MB+m, n) of the M×NB matrix, where the Z+ denotes the set of positive integers;
• and
• fourth step:
• extending K columns based on each column of the constructed M×NB matrix.