摘要
基于LDPC码,提出一种新颖的随机交织型级联码(RICC,random interleaved concatenatedcode)方案。在编码阶段,根据LDPC码中不同度数的变量节点采用不同纠错能力的BCH外码,分别进行保护的思想进行集分割编码;在译码阶段,采用硬判决辅助软判决的联合迭代译码。不同于传统的单极型和交织型级联方式,它是一种根据LDPC码变量节点(VN)度数来决定交织深度,因而交织方式是随机的。仿真结果分析表明,在误比特率(BER)为10-8时,四集合分割的RICC-4P的净编码增益(NCG)比无分割的单级型级联码提高了0.15dB,比ITU-T G.709和G.975.1标准中的RS(255,239)、RS(255,239)+CSOC(n/k=7/6,J=8)级联码和开销为25%的正交级联BCH码的NCG分别提高了3.0、1.5和0.4dB,其纠错性能的提升得益于采用集分割保护和硬判决辅助软判决的联合迭代译码。
A new random concatenated coding scheme based on LDPC code is proposed. For the coding al- gorithm of the scheme,different degrees of variable nodes are protected by different BCH codes with dif ferent error correction capabilities. And for the decoding algorithm of this scheme, a joint iterative decocling （JID） method is proposed, which takes hard decision to assist soft decisiorL This scheme is different from the traditional single-level type and interleaved type concatenated codes. Its interleaved depth is determined according to the degree of the variable nodes of the LDPC code. So its interleaved manner is random. The simulation results show that when bit error ratio （BER） is 10-8 , compared with the single level type concatenated code,RS （255,239） code in ITU-T G. 709,RS（255,239）＋~ （n/k=7/6,J ~8） in ITU-T G. 975.1 and orthogonal concatenated BCH code with 25% overhead,the net coding gain （NCG） of the four-partition random interleaved concatenated code （RICC-4P） is improved by 0. 15 dB, 3 dB,1.5 dB and 0.4 riB,respectively. The performance improvement is due to the set-partition protec- tion and the JID algorithm based on the soft decision with hard decision assistant.
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2013年第4期692-697,共6页
Journal of Optoelectronics·Laser
基金
国家自然科学基金(61071117
61171158
61275077)
重庆市科委(2009BB2285
2010BB2413
2010BB2409)
重庆市教委(KJ110519
KJ110527)资助项目
关键词
随机交织型级联码(RICC)
单级型级联码
光通信系统
random interleaved concatenated code （RICC） single-level type concatenated code opticalcommunication system
