Abstract: The codec includes an encoding/decoding operation module and a basic matrix storage module. In the stored basic matrix Hb, for all girths with length of 4, any column element of i, j, k or l constituting the girths in anti-clockwise or clockwise always satisfies inequality: (i?j+k?1) mod z?0, wherein z is the extension factor. When generating the basic matrix, firstly the number of rows M, number of columns N, and weight vectors of the rows and columns are determined, an irregularly original basic matrix is constructed; then the position of ‘1’ is filled by a value chosen from set {0, 1, 2, . . . , z?1} to obtain the basic matrix Hb. The basic matrix Hb obtained by storing constitutes the desired encoder/decoder. The encoder/decoder according to the present invention can effectively eliminate error-floor phenomenon of LDPC codes and accelerate the falling speed of BER curve.

Abstract: The invention relates to a base matrix, a encoder/decoder of Low Density Parity Check (LDPC) codes and a generation method thereof. The encoder/decoder is determined uniquely by the parity check matrix of the LDPC codes. With different code sizes, said parity check matrix can be obtained by expanding different base matrixes, and also can be obtained by expanding a unique base matrix after correction. Elements of said base matrix must meet an inequation in which the girth value is up to the standard, e.g. when girth?6, for any element i, j, k, l in the matrix which forms the short loop having a length of 4 in anticlockwise, there are always mod(i?j+k?l, z) unequal to 0.

Abstract: The invention relates to a base matrix, a encoder/decoder of Low Density Parity Check (LDPC) codes and a generation method thereof. The encoder/decoder is determined uniquely by the parity check matrix of the LDPC codes. With different code sizes, said parity check matrix can be obtained by expanding different base matrixes, and also can be obtained by expanding a unique base matrix after correction. Elements of said base matrix must meet an inequation in which the girth value is up to the standard, e.g. when girth ?6, for any element i, j, k, l in the matrix which forms the short loop having a length of 4 in anticlockwise, there are always mod(i?j+k?l, z) unequal to 0.