光通信中基于SCG(4,k)码的一类改进LDPC码构造方法  

An Improved Construction Method of LDPC Codes Based on SCG(4,k) Codes for Optical Communications

作　　者：袁建国[1] 谢亚[1] 刘文龙[1] 黄胜[1] 王永[1] 

机构地区：[1]重庆邮电大学光纤通信技术重点实验室,重庆400065

出　　处：《半导体光电》2013年第1期115-118,共4页Semiconductor Optoelectronics

基　　金：国家自然科学基金项目(61071117;61003256);重庆市自然科学基金项目(2010BB2409);重庆市教委项目(KJ110519)

摘　　要：针对SCG(4,k)码构造方法的分析与研究,提出一种适用于光通信系统中改进的新颖低密度奇偶校验(LDPC)码构造方法。该方法在保留SCG(4,k)构造方法的基础上,采用类似于准循环的构造形式,使生成的码字不受短环干扰,并具有良好的围长特性;并且与改进前的SCG(4,k)码相比,该构造方法具有硬件实现方面节省存储空间和降低计算复杂度等优点。采用该方法构造了码率为93.7%的LDPC(3969,3720)码。仿真结果表明:这种码的净编码增益(NCG)比广泛用于光通信系统中的经典RS(255,239)码提高了1.99dB。A novel construction method of low density parity （LDPC） code to be suitable for optical communication systems, based on the analysis and research of the construction method of Systematically Constructed Gallager（SCG）（4,k）, was proposed. The novel construction method keeps the basic form of the construction method of SCG（4,k） and uses the similar structure of the Quasi-cyclic form, which makes the generated code avoid the interference of the short ring and have the good girth characteristics. Compared with common SCG （4, k） code, this novel construction method has such advantages as saving storage space and reducing computation complexity in the hardware realization. The LDPC（3969,3720） code with 93.7% high code-rate is constructed by applying the novel construction method. The simulation analysis shows that the net coding gain（NCG） of the LDPC（3969,3720） code is 1.99 dB.more than that of the classic RS （255,239） widely used in optical communication systems.

关 键 词：SCG 低密度奇偶校验码 净编码增益(NCG) 误码率 光通信系统 

分 类 号：TN929.11[电子电信—通信与信息系统]