一种适用于光通信系统中的QC-LDPC码的构造  

Construction of QC-LDPC codes for optical communication systems

作　　者：彭大芹[1] 朱述民 PENG Da-qin;ZHU Shu-min(Cooperative Innovation Center for Next Generation of Information Network and Teriminal in Chongqing,Electronic Information and Networking Research Institute, Chongqing University of Posts and Telecommunications, Changqing 400065 ,Chin)

机构地区：[1]“新一代信息网络与终端”重庆市协同创新中心,电子信息与网络工程研究院,重庆邮电大学,重庆400065

出　　处：《光电子．激光》2018年第7期713-717,共5页Journal of Optoelectronics·Laser

基　　金：工信部新一代宽带无线移动通信网重大专项和LTBV无线传输技术标准化及样机研发验证(2016ZX03002019-007)资助项目

摘　　要：为了满足快速发展的光通信系统不断扩大的需求,基于有限域的两个不同本原元提出了一种准循环低密度奇偶校验(Quasi-Cyclic Low-Density Parity-Check,QC-LDPC)码的构造方法,构造的基矩阵中不含4环,译码时纠错性能良好。将两个本原元组合,通过调整基矩阵结构,使构造的码字最小距离增大,从而提升码字的纠错性能。仿真结果表明:在相同的仿真环境下,当误比特率(Bit Error Rate,BER)为10^(-6)时,构造的码率为93.7%的QC-LDPC(3 780,3 540)码的净编码增益(Net Coding Gain,NCG)比同样是利用有限域本原元(Primitive Elements,PE)构造的PE-QC-LDPC(3780,3540)码,提高了0.38dB;同时,与适用于光通信中利用有限域中两个不同子群(Sub-Groups,SG)构造的SG-QC-LDPC(3 780,3 540)码和已广泛应用于光通信的ITU-T G.975.1标准中的LDPC(32 640,30 592)码相比,净编码增益分别有0.2dB和0.72dB的提升。In order to meet the needs of high-speed development of optical comm unication systems,a construction method of quasi-cyclic low-density parity-check （QC-LDPC） codes based on two different primitive elements of finite field is proposed.The Tanner graph of parity check matrix of the code constructed by this method has no cycles of length 4,which makes they have the excellent de coding convergence characteristics.Besides,by properly combining the two primitive elements of th e base matrix,the matrix structure is adjusted,so that the constructed code has a good distance property and an improvement of the error correction performance.Simulation results show that when the bit error rate （BER） is 10-6,in the same simulation environment,the net coding gain （NCG） of the proposed QC-LDPC（3780,3540） code with the code rate of 93.7% in this paper is improved 0.38dB than that of the PE-QC-LDPC（3780,3540） code based on the primitive element （PE） of finite field.In addition,the NCG of the proposed QC-LDPC（3780,3540） code is respectively 0.2dB and 0.72dB higher than those of the SG-QC-L DPC（3780,3540） code based on two different sub-groups （SG） over finite field,which is suitable for optical comm unication and the LDPC（32640,0592） code in ITU-T G.975.1w hich is widely used in optical communication.

关 键 词：准循环低密度奇偶校验码 有限域 本原元 最小距离 

分 类 号：TN911.22[电子电信—通信与信息系统]