时变信道中联合信道估计的单载波迭代均衡接收机  

A Single Carrier Iterative Equalization Receiver for Joint Channel Estimation in Time-Varying Channels

作　　者：兰林瑶 穆鹏程[1] LAN Linyao;MU Pengcheng(Faculty of Electronic and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China)

机构地区：[1]西安交通大学电子与信息学部,西安710049

出　　处：《西安交通大学学报》2021年第12期138-145,共8页Journal of Xi'an Jiaotong University

基　　金：陕西省自然科学基础研究计划资助项目(2018JM6071);西安交通大学基本科研业务费自由探索与创新项目(xjj2018015)。

摘　　要：针对宽带无线通信信道的时变性和多径时延问题,提出了一种联合信道估计的单载波迭代均衡接收机。首先,根据多径时延带来的信号分集可能性,设计反馈滤波器组,尽可能消除不同时延信号间的符号间干扰;然后,设计前馈滤波器,将经过干扰消除后的多路信号进行分集合并,从而获得分集增益;最后,根据导频信息和迭代均衡模块输出的软信息,利用复指数基扩展模型对信道进行迭代估计。仿真结果表明:与现有的快时变信道下联合信道估计的迭代均衡方法相比,所提出的方法在时延扩展较大而多普勒频偏较小的情况下,当误比特率为10^(-5)时,迭代3次后的性能改善为1 dB,距离匹配滤波界约为1 dB;在多普勒频偏较大而时延扩展较小的情况下,当误比特率为10^(-5)时,迭代3次后的性能改善约为2 dB,距离匹配滤波界约为0.8 dB。A single carrier iterative equalization receiver with joint channel estimation is proposed to solve the time-varying and multipath delay problems in broadband wireless communication channels.Firstly,according to the possibility of signal diversity brought by multipath delay,feedback filter banks are designed to eliminate the inter symbol interference among different delay signals as much as possible.Then,a feedforward filter is designed to combine the multipath components after interference elimination,so as to obtain diversity gain.Finally,according to the pilot information and the soft information output by the iterative equalization module,the channel is iteratively estimated by using the complex exponential basis extension model.Simulation results and a comparison with the existing iterative equalization method for joint channel estimation under fast time-varying channel show that the performance of the proposed method improves by 1 dB and is about 1 dB away from the matched filter bound after three times of iterations in the case of large delay spread and small Doppler frequency offset when the bit error rate is 10^(-5).When the bit error rate is 10^(-5) in the case of small delay spread and large Doppler frequency offset,the performance of the proposed method improves by about 2 dB and is about 0.8 dB away from the matched filter bound after three times of iterations.

关 键 词：单载波 迭代均衡 滤波器组 迭代信道估计 基扩展模型 

分 类 号：TN911[电子电信—通信与信息系统]