LDPC编码辅助的判决反馈信道估计与均衡方法  

LDPC-aided Decision Feedback Channel Estimation and Equalization Method

作　　者：李佳宣 丁旭辉[2] 杨凯[1] 代计博 卜祥元[1] 安建平[2] LI Jiaxuan;DING Xuhui;YANG Kai;DAI Jibo;BU Xiangyuan;AN Jianping(School of Information and Electronics,Beijing Institute of Technology,Beijing 100081,China;School of Cyberspace Science and Technology,Beijing Institute of Technology,Beijing 100081,China;National Key Laboratory of Science and Technology on Aerospace Intelligence Control,Beijing Aerospace Automatic Control Institute,Beijing 100854,China)

机构地区：[1]北京理工大学信息与电子学院,北京100081 [2]北京理工大学网络空间安全学院,北京100081 [3]北京航天自动控制研究所宇航智能控制技术国家级重点实验室,北京100854

出　　处：《兵工学报》2024年第4期1168-1175,共8页Acta Armamentarii

基　　金：国家重点研发计划项目(2019YFB1803200)。

摘　　要：信道频率选择性衰落较强的环境下,传统正交频分复用非盲信道估计与均衡方法的系统误码性能较差,且需要在信号中增加导频符号的插入,降低系统吞吐量。针对上述问题,提出一种低密度奇偶校验(Low-Density Parity-Check,LDPC)编码辅助的判决反馈信道估计与均衡方法。将LDPC编码增益引入判决反馈回路中,以提升收敛性,在插入极少导频符号的条件下达到渐进非盲信道估计与均衡方法的性能。另外提出一种基于条件最大似然原则的信道估计改进算法,以恒虚警原则检测有效抽头信号以提高信道估计精度,并且能够与判决反馈信道估计与均衡方法相结合,进一步提升算法性能。仿真结果表明,在仿真所选用的信道环境下,LDPC编码辅助的判决反馈信道估计与均衡方法相比传统判决反馈方法具有11~13 dB的误码性能提升,具有优秀的系统误码性能和鲁棒性。Under the environment of severely channel frequency selective fading,the traditional orthogonal frequency division multiplexing(OFDM)non-blind channel estimation and equalization method has poor system bit error rate performance,and needs to increase the insertion of pilot symbols in a signal,which reduces the system throughput.A low density parity check code(LDPC)-aided decision feedback channel estimation and equalization method is proposed for the above problems.The proposed method introduces the LDPC coding gain into the decision feedback loop,which improves the convergence.And it achieves the asymptotic performance of non-blind channel estimation and equalization methods under the condition of few pilot symbols inserted.Meanwhile,an improved channel estimation algorithm based on conditional maximum likelihood(CML)principle is proposed.This algorithm detects the effective tap signals based on the principle of constant false alarm to improve the channel estimation accuracy,and can be combined with the proposed decision feedback channel estimation and equalization method.The simulated results show that,under the channel environment selected in the simulation,the LDPC-aided decision feedback channel estimation and equalization method has 11-13 dB improvement in bit error performance compared with the traditional decision feedback method,and has excellent system error performance and robustness.

关 键 词：正交频分复用 多径信道 信道估计与均衡 判决反馈 条件最大似然估计 

分 类 号：TN911[电子电信—通信与信息系统]