基于FrFT优化窗的STFT及非线性调频信号瞬时频率估计

Instantaneous Frequency Estimation Using STFT with an Optimal Window by Fractional Fourier Transform

瞬时频率(IF)是描述非平稳调频信号最基本的参数,调频信号广泛应用于声纳、雷达、通讯和生物等领域。本文采用分数阶Fourier变换来优化STFT的窗函数,并估计非线性调频信号的瞬时频率。进行了详细的误差理论分析。同时在实验上和Wingner分布(WVD)、短时Fourier变换(STFT)进行误差(MSE)比较分析。仿真证明,FrFt优化窗STFT对估计非线性调频信号的瞬时频率具有良好的性能。

Abstract: The instantaneous frequency(IF)is a basic parameter which may be used to describe the non-stationary frequency-coded signals in a process, Which is used in many areas such as seismic, radar, sonar, communications and biomedical applications. The paper adopt Fractional Fourier Transform to optimize the window of STFT an use it to estimate IF of non-linear frequency-modeled signal (NLFM) and analyze the MSE detailedly by theoretics. At the same time, Compared with WVD, STFT by computer simulation. It has been show excellent performance for IFE of NLFM.