一种新的基于光纤信道LDPC码的16QAM调制解调算法  

A Novel Modulation and Demodulation Algorithm of 16QAM-LDPC Code in Optical Channel

作　　者：边绍松[1] 张琦[1] 

机构地区：[1]北京邮电大学电子工程学院,北京100876

出　　处：《软件》2012年第11期194-197,共4页Software

基　　金：基国家自然科学基金No.61275158;61201151;国际合作项目No.2012DFG12110;中央高校基本科研业务费专项资金资助2011PPB-00-32

摘　　要：针对提高光纤通信系统中LDPC编译码方案频谱利用率的问题,本文研究了光纤通信系统中具有较高频谱效率的LDPC高阶调制方案,重点以16QAM调制的LDPC为例分析了基于卡方分布的光纤信道中软解调对数似然比的理论推导,提出并推导了其简化算法,设计了16QAM-LDPC的光纤通信系统方案。仿真结果表明,采用16QAM软解调译码算法能带来较好的系统性能,当码长2304,码率为5/6的QC-LDPC码在时,对应的Q=9.1dB。其相应的简化算法在0.2dB的性能损失代价下,可以具有较低的译码复杂度。To improve the spectrum utilization of LDPC coding scheme in optical fiber channel, a new LDPC scheme with high order modulation was studied in this paper. The research mainly concentrated on 16QAM-LDPC code, deduced the soft LLR algorithm in optical channel based on chi-square distribution, and further obtained the simplified algorithm. At last, we simulated the proposed LDPC scheme in MATLAB. The experimental results show that, the proposed scheme can provide a good performance with high spectrum utilization. When using codes with length^2304 and rate=5/6, we can achieve a Q=9. ldB in .While the corresponding simplified algorithm can have a low decoding complexity at the cost of performance loss of 0.2riB.

关 键 词：光纤通信 IX)PC码 高阶调制 对数似然比 

分 类 号：TN70[电子电信—电路与系统]