适用于BICM-ID系统的星座成形方法  

Simple constellation shaping for BICM-ID

作　　者：李琪[1] 周林[2] 张博[1,3] 白宝明[1,4] 

机构地区：[1]西安电子科技大学综合业务网理论及关键技术国家重点实验 [2]华侨大学信息科学与工程学院 [3]96401部队 [4]通信网信息传输与分发技术重点实验室

出　　处：《通信学报》2015年第6期149-156,共8页Journal on Communications

基　　金：国家重点基础研究发展计划("973"计划)基金资助项目(2012CB316100);国家自然科学基金资助项目(61372074;61302095);通信网信息传输与分发技术重点实验室开放课题基金资助项目(ITD-U12006)~~

摘　　要：结合几何成形与概率成形的思想,提出了一种适用于比特交织编码调制系统的星座成形映射方法。该方法基于实用信号星座,通过不使用部分能量较大的信号点并利用多对一的映射关系,使发送信号逼近最佳输入概率分布。利用解调器和译码器之间的迭代译码,该方法可方便地获得成形增益。基于容量和外信息转移图分析,给出了信号星座和信号到符号映射的优化方法。理论分析和仿真结果表明,在高斯白噪声信道和独立Rayleigh衰落信道下,该映射方法利用大信号星座在采用迭代译码的比特交织编码调制系统中均能取得优于传统Gray映射的误码性能,且随着调制阶数的增大可进一步提高成形增益。A novel method of constellation mapping is presented for bit-interleaved coded modulation（BICM） by combining geometry shaping with probabilistic shaping. The transmitted signal points of a practical signal constellation approach the optimal input distribution by exploiting a many-to-one mapping with some signal points unused. With this method, shaping gain can be achieved conveniently with the help of iterative decoding between demodulation and decoder. The optimizations of signal constellation and the mapping from symbols to signal points are performed by the analysis of capacity and the extrinsic information transfer chart. Simulation results show that the proposed constellation mapping outperforms the traditional Gray mapping for BICM with iterative decoding in both AWGN and Rayleigh channels. And the shaping gain achieved can be improved with the increase of the constellation size.

关 键 词：比特交织编码调制 迭代译码 映射方式 成形增益 外信息转移图 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]