QAM调制下基于卷积码与累加编码调制级联的纠错码性能研究  

Research on the Performance of Error Correction Codes Based on Convolutional Code and Accumulative Code Modulation Cascade under QAM Modulation

作　　者：向劲松[1] 陈怀柔 XIANG Jinsong;CHEN Huairou(School of Communication and Information Engineering,Chongqing University of Posts and Telecomm.,Chongqing 400065,CHN)

机构地区：[1]重庆邮电大学通信与信息工程学院,重庆400065

出　　处：《半导体光电》2023年第6期924-930,共7页Semiconductor Optoelectronics

基　　金：国家自然科学基金资助项目(61571072)。

摘　　要：基于卷积码与累加编码的PPM调制级联码(SCPPM)在泊松信道光PPM调制下具有极优异的性能。文章将这种累加编码结构引入到QAM调制中,分析其性能。将卷积码+累加编码+QAM调制串行级联(SCAQAM)纠错方案与常规基于卷积码、并行级联卷积码(Turbo)以及低密度奇偶校验码(LDPC)的比特交织编码调制迭代译码(BICM-ID)系统进行比较,并进一步比较了SCAQAM系统的自然、格雷、反格雷星座映射方式。结果表明,在高阶QAM调制下,这种纠错结构具有极优异的误码性能。对于16QAM及64QAM调制,SCAQAM相对于另外几种纠错码结构的BICM-ID系统分别有约0.3和0.5 dB的性能提升,只有卷积码与累加码结合才更具性能优势。并且SCAQAM将累加后的比特流以反格雷方式映射具有更优异的性能。The PPM modulation cascade code based on convolutional codes and acumulative code(SCPPM)has excellent performance in Poisson channel optical PPM modulation.In this paper,this acumulative code structure was introduced into QAM modulation and its performance was analyzed.A comparison was made between the convolutional code,acumulative code,and QAM modulation serial concatenation(SCAQAM)error correction scheme and the conventional bit interleaved encoding modulation iterative decoding(BICM-ID)system based on convolutional code,parallel concatenated convolutional code(Turbo),and low density parity check code(LDPC).And further compared the nature,Gray,and anti-Gray constellation mapping methods of the SCAQAM system.The results show that under high-order QAM modulation,this error correction structure has excellent error rate performance.For 16QAM and 64QAM modulation,SCAQAM has a performance improvement of about 0.3 and 0.5dB,respectively,compared to other BICM-ID systems with error correction code structures.Only the combination of convolutional code and accumulation code has a performance advantage.And SCAQAM has superior performance in mapping the accumulated bitstream in an anti-Gray manner.

关 键 词：正交幅度调制 星座映射 迭代译码 累加编码 

分 类 号：TN911.22[电子电信—通信与信息系统]