瞬时频率估计方法对比研究

在信号处理中,线性调频信号（linear frequency modulation,LFM）的参数估计是一类非常重要的问题。本文基于短时傅里叶变换（short-time fourier transform,STFT）、连续小波变换（continuous wavelet transform,CWT）和维格纳（wigner-ville distribution,WVD）分布等三种方法,对两种常用信号（单频信号和线性调频信号）的瞬时频率进行估计,并对其做出比较分析,CWT法适用于单频信号的瞬时频率估计,WVD法适用于调频信号的瞬时频率估计。针对这三种方法出现的边缘问题,用最小二乘法进行拟合,有效的得到解决。

Comparative study of instantaneous frequency estimation methods

In signal processing community,parameter estimation of LFM falls in an important series of problems.In this paper,we investigate three signal processing methods：Short-Time Fourier Transform（STFT）,Continuous Wavelet Transform（CWT） and Wigner-Ville Distribution（WVD） respectively.We analyze these three methods by implementing them to estimate the instant frequencies of two commonly used signals：CW and LFM.In order to further study the different properties and application patterns of the three aforementioned methods,we conduct a comparison analysis between them.CWT is more suitable for Single-frequency signal processing;for linear FM signal,WVD has better results than that of the other two methods.In order to solve the boundary problems of the three methods,least-squares fitting is applied to post-process the final results.