时延估计技术及其在多途环境中的应用

Time-delay estimation and its application in multipath environment

将Ｖａｃｃａｒｏ等人提出的带惩罚函数的最小二乘算法和Ｌｉ等人提出的ＷＲＥＬＡＸ时延估计算法结合起来，给出了一种时延估计问题的混合算法，其中ＷＭＬＡＸ算法用于计算重叠信号时延和幅度的初始值，带惩罚函数的频域最小二乘算法用于确定重叠信号时延和幅度的真实值。本文还介绍了利用相关系数进行时延估计运算以及确定有效多途信号数目的方法，并成功地运用到实验数据处理。模拟数据显示混合算法具有很强的处理重叠多途信号，以及抗噪声干扰的能力。对实验获得的时带积（ＴＢ）为 ８００，带宽从 ５００ Ｈｚ到 ７００ Ｈｚ的线性调频（ＬＦＭ）信号，利用相关系数获得的重构接收信号与接收信号符合得非常好。

A hybrid algorithm combining the NLS estimator with penalty function proposed by Vaccaro and WRELAX algorithm proposed by Li is presented, where WRELAX algorithm and the NLS estimator with penalty function are used to obtain the initial estimates and the true values of the delays and the amplitudes of the superimposed signals,respectively. The methods for calculation of time-delay estimation using the correlation coefficient and for determining the number of effective multipath signals are also proposed. Numerical examples are provided to illustrate the performances of the hybrid algorithm. The experimental data of f = 500-700 Hz linear frequency modulation (LFM ) signals with large t line-bandwidth-pro duct 800 is emphatically discussed here. The results show t hat the reconstructed signal is similar to the received signal in correlation space.