单信道混合数字通信信号的时延估计方法

Time Delay Estimation for Single-channel Mixed Digital Communication Signals

单通道混合通信信号的参数估计是无线通信信号处理的热门方向。本文针对单信道两路数字通信信号混合的时延估计问题,根据混合信号的循环自相关函数与信号调制参数的关系,提出了两种基于循环自相关的时延估计方法。两种方法分别针对信道参数未知的情况和信道参数已知的情况,利用循环自相关函数构建关于两路时延参数的方程组,通过解方程组获得了两路信号时延的闭式估计。另外本文也对单通道混合数字通信信号时延估计的克拉美罗界进行了分析。最后利用计算机仿真实验,考察了不同条件下两种方法的性能,表明了它们的性能特点和适用的条件。

Single channel mixed signal parameter estimation is a hot topic in wireless communication and signal process-ing.In this paper,two cyclic auto-correlation based time estimation methods are presented for single-channel mixed com-munication signals,which is based on the relationship of cyclic autocorrelation functions and signal’s modulation parame-ters.The two different methods are designed for scenarios of unknown and known channels of both signals respectively.The methods treat both co-channel signals as desired signals.Firstly,cyclic autocorrelation function of the received mixed signal is analyzed,and then the linear equations on time delay parameters are established for the two scenarios.Secondly,the closed-form solution for time delay parameters of both co-channel signals is obtained by solving the equations,and two esti-mation algorithms are presented.The Cramer-Rao bound is also analyzed in this paper.Finally,computer simulation re-sults are provided to demonstrate the performance of the proposed methods and their application conditions.