水声信道频域Turbo均衡的期望传播改进算法  

Improved Expectation Propagation Algorithm of Frequency Domain Turbo Equalization for Underwater Acoustic Channels

作　　者：姜斌[1,2] 唐禹 包建荣 唐向宏[1] 刘超[1] JIANG Bin;TANG Yu;BAO Jian-rong;TANG Xiang-hong;LIU Chao(School of Communication Engineering,Hangzhou Dianzi University,Hangzhou,Zhejiang 310018,China;School of Electronic Information,Hangzhou Dianzi University,Hangzhou,Zhejiang 310018,China)

机构地区：[1]杭州电子科技大学通信工程学院,浙江杭州310018 [2]杭州电子科技大学电子信息学院,浙江杭州310018

出　　处：《电子学报》2022年第3期652-662,共11页Acta Electronica Sinica

基　　金：国家自然科学基金(No.U1809201);浙江省自然科学基金(No.LY20F010010);浙江省属高校基本科研业务费专项资金项目(No.GK209907299001-003)。

摘　　要：针对水声信道带限,稀疏及长时延特性,并考虑水声实时高质量通信需求,提出了一种基于期望传播(Expectation Propagation,EP)的迭代信道估计和频域Turbo均衡(EP based Iterative Channel Estimation-Frequency of Domain Turbo Equalization,EP-ICE-FDTE)算法.其利用EP算法迭代估计传输符号的先验及后验分布,并将后验概率软映射符号提升信道估计精度.故该EP通过优化符号概率估计和信道估计,使Turbo均衡的干扰消除性能得到提高.此外,为了降低系统时延,还利用低复杂度频域Turbo均衡处理接收信号.仿真表明:所提EP-ICE-FDTE算法能实现更优的接收信号恢复效果.在静止和时变水声信道,该算法较目前较好的迭代信道估计-频域判决反馈的频域Turbo均衡(Iterative Channel Estimation-Frequency Domain Decision Feedback-Frequency Domain Turbo Equalization,ICE-FDDFFDTE)算法,分别有3.4 dB,1.3 dB性能增益.According to the band-limited,sparse and long-delay characteristics of the underwater acoustic(UWA)channels,and considering the requirements for real-time high-quality UWA communication,an expectation propagation(EP)based iterative channel estimation and frequency domain turbo equalization(EP-ICE-FDTE)algorithm is proposed.The EP is used to iteratively estimate the a priori and a posterior distribution of the transmitted symbols,and the posteriori probability soft-mapped symbols are used to improve the accuracy of channel estimation.Therefore,EP improves the perfor⁃mance of Turbo equalization interference cancellation by optimizing symbol probability and channel estimation.Simula⁃tions indicate that the proposed algorithm obtains better received signal recovery than those of traditional ones.The pro⁃posed EP-ICE-FDTE obtains 3.4 dB,1.3 dB performance gains,when compared with those of the currently well iterative channel estimation-frequency domain decision feedback-frequency domain Turbo equalization(ICE-FDDF-FDTE)in static and time-varying UWA channels,respectively.

关 键 词：水声通信 期望传播算法 软迭代信道估计 频域Turbo均衡 

分 类 号：TN911[电子电信—通信与信息系统]