A novel construction method of the QC-LDPC code based on finite field additive group for optical communications
Yong Wang · Journal of Optoelectronics·laser · 2013
Based on finite field(GF(q)) additive group,a novel construction method with the advantages of simple construction and easy implementation of quasi-cyclic low-density parity-check(QC-LDPC) codes for optical communication systems is proposed in order to meet the increasing requirement on the transmission characteristics.The novel construction method can flexibly adjust the code-length and code-rate,and furthermore,the complexity of the encoding and decoding in lower.A regular QC-LDPC(4599,4307) code to be suitable for optical communication systems is constructed by applying the proposed method.The simulation results show that at the condition of the bit error rate(BER) of 10-7 and the same code rate of 93.7%,the net coding gain(NCG) of the constructed QC-LDPC(4599,4307) code is 2.2 dB more than that of the classic RS(255,239) code which has widely been applied in optical communication systems,and 0.47 dB and 0.25 dB more than those of the SCG-LDPC(3969,3720) code constructed by the systematically constructed gallager(SCG) construction method and the irregular QC-LDPC(3843,3603) code respectively,and is 1 dB away from the Shannon limit.Therefore,the novel QC-LDPC(4599,4307) code has superior error-correction performance and is more suitable for the high-speed long-haul optical communication systems.