Method and device for constructing check matrix of LDPC (Low Density Parity Check) code

The invention discloses a method and a device for constructing a check matrix of an LDPC (Low Density Parity Check) code. The method comprises the following steps: constructing an MB * NB dimensional basic matrix B used for generating an LDPC code with a code rate of R and a code length of N, wherein MB = M/K, NB = N/K, M = N * (1-R), K is an expansion ratio of the basic matrix, K belongs to phi, and phi is a set of common factors of M and N; selecting the number of '1' in each row and each column of the basic matrix B, so that the row weight distribution and the column weight distribution of the basic matrix B meet preset node degree distribution; the position of '1' in each row and each column in the basic matrix B is adjusted, so that an MB * MB-dimensional sub-matrix composed of the rear MB columns of the basic matrix B is in a full rank; replacing elements in the basic matrix B with a K * K matrix, and expanding the basic matrix B into an M * N-dimensional check matrix H; 本发明公开了一种LDPC码的校验矩阵的构造方法和装置。所述方法包