水声信道多径时延估计的高分辨方法研究

为了解决传统的匹配滤波器方法估计实测信道时分辨率不足的困难，研究了高分辨多径时延估计方法。应用MODE算法求得多径时延估计的初值，再通过带惩罚函数的最小二乘法迭代求解时延和幅度估计的准确值。仿真表明，该方法的时延分辨率在20dB信噪比下达到了传统的匹配滤波器方法的4倍，实现了多径时延的高精度估计，解决了实测线性调频信号的信道估计问题。

High Resolution Method for Underwater Multipath Time Delay Estimation

A hybrid algorithm for the high resolution multipath time delay estimation was proposed to overcome the shortcoming of low resolution of the matched filtered method when estimating a channel measured at sea. First, the estimate of multipath time delay was obtained by using eigenvalue decomposition with the MODE algorithm, then the time delay and the corresponding gain estimate was refined with the NLS (nonlinear least square) estimator. Simulation results show that this method reaches a high resolution 4 times over the conventional matched filter method under the SNR of 20dB, and it is also superior to the WRELAX-NLS method. In the end, simulation on the linear frequency modulated (LFM) signal measured at sea is presented to prove the effectiveness of our method.