A Class of Irregular LDPC Codes with High Performance and Low Encoding Complexity
一种高性能低复杂度的非规则LDPC码的构造方法

A class of structured irregular Low-Density Parity-Check (LDPC) codes with high performance and low complexity is proposed in this paper. First, a global matrix M with a triangular plus dual-diagonal form based on Improved eIRA (IeIRA) method is designed. Then, each ‘1’ in the global matrix M is replaced with a permutation matrix; each ‘0’ is replaced with a null matrix to generate the parity check matrix H. Finally, the relationship between the length of short cyclic in the parity matrix H and the cyclic shift coefficient is given. Based on the relationship, error floor of BER is lowed by selecting proper cyclic shift coefficient of each permutation matrix. Simulation shows that the proposed method can reduce the number of small stopping set, increase the minimum distance of LDPC codes, and achieve very low error floor with linear encoding complexity.