Constructions of QC LDPC codes based on integer sequences

摘要

Based on difference sequence and Hoey sequence,three types of（2,F）and（3,F）quasi cyclic（QC）low-density parity-check（LDPC）codes are constructed.All 4-cycles and even 6-cycles are removed in the Tanner graph,and the girth is not less than six.The decoding complexity as well as extension to irregular case is analyzed.Simulation results show that in AWGN and Rayleigh fading channels,the codes can achieve the same error performance as their counterpart PEG codes,and outperform the corresponding MacKay codes and array codes.