A Novel Concatenated Code Based on LDPC Codes for Optical Communications
Yuan Jiangu · Bandaoti guangdian · 2014
A novel SCG low density parity check SCG-LDPC(3969,3720)code for optical communication systems,based on the optimization and improvement for the construction method of Systematically Constructed Gallager(SCG)(4,k)code,was constructed.The novel SCG-LDPC(6561,6240)code with the code-rate of 95.1% was constructed by increasing the code-length of SCG-LDPC(3969,3720),so that the code-rate of LDPC codes can better meet the high code-rate requirements of optical communication systems.And then the novel BCH(127,120)+LDPC(6561,6240)concatenated code was constructed by concatenating SCG-LDPC(6561,6240)code and BCH(127,120)code with the code-rate of 94.5%.The simulation analysis shows that at the bit error rate(BER)of 10-7,the net encoding gain(NCG)of the BCH(127,120)+LDPC(6561, 6240)concatenated code is respectively 2.27dB and 0.49dB more than those of the classic RS(255,239)code and SCG-LDPC(6561,6240)code.Therefore,the novel BCH(127,120)+LDPC(6561,6240)concatenated code can be better suitable for optical communication systems.