基于改进基追踪去噪的水声单载波频域均衡信道估计  

Underwater acoustic channel estimation in single carrier frequency domain equalization based on improved basis pursuit denoising

作　　者：柳文明 韩树平[1] 李厚全[1] 徐景峰[1] LIU Wenming;HAN Shuping;LI Houquan;XU Jingfeng(Naval Submarine Academy, Qingdao 266199, China)

机构地区：[1]海军潜艇学院,青岛266199

出　　处：《应用声学》2017年第5期417-423,共7页Journal of Applied Acoustics

基　　金：中国博士后基金资助项目(2014M552658)

摘　　要：针对低信噪比下单载波频域均衡信道估计精度低导致均衡效果差的问题,利用基追踪去噪方法估计稀疏信道有效抽头具有的稳定特性,提出了一种在平稳水声信道条件下单载波频域均衡系统中应用的改进基追踪去噪稀疏信道估计方法。方法利用延拓循环前缀作为导频进行多次信道估计,将估计结果累积平均,再采用门限判决提取有效抽头得到信道估计值,从而提高了稀疏信道的估计精度。通过合理选择循环前缀延拓次数,尽可能地降低导频长度对频带利用率的影响。仿真对比分析了改进基追踪去噪算法与匹配滤波、最小平方以及传统基追踪去噪信道估计算法的性能以及对单载波频域均衡系统误码率的影响。仿真实验结果表明,改进基追踪去噪信道估计算法具有更优的估计精度,在单载波频域均衡系统中可以提高约3 dB的接收信噪比增益。Considering that underwater acoustic channel estimation in single carrier frequency domain equalizationis imprecise in the condition of low SNR,and lead to low equalization precision,based on the stabilitycharacteristics of estimating effective taps of sparse channel using the basis pursuit denoising(BPDN)method,an improved BPDN estimation method for sparse channel is proposed in SC-FDE system in stable underwateracoustic channel.By using the extension of the cyclic prefix as a pilot to estimate channel repeatedly,cumulateaverage the estimation results,then extract the effective channel tap estimates by threshold decision,thus improving the estimation accuracy of the sparse channel.By choosing the proper number of cyclic prefixextension,the effect of pilot frequency on the frequency band utilization is reduced as much as possible.The performance of the improved BPDN algorithm and matched filtering,least square and traditional BPDNchannel estimation algorithms are analyzed and compared,and the influence on bit-error-ratio of SC-FDEsystem is analyzed.Simulation results show that the improved BPDN channel estimation algorithm has betterestimation accuracy,and can increase the received SNR gain about3dB in the SC-FDE system.

关 键 词：基追踪去噪 稀疏信道估计 单载波频域均衡 累积平均 

分 类 号：TN929.3[电子电信—通信与信息系统]