用相位差分和Wigner分布估计信号瞬时频率

Estimation of Instantaneous Frequency of a Signal Using the Phase Difference and the Wigner Distribution

时变信号瞬时频率的测量有许多重要的应用。例如,在地震勘探、雷达、声纳、通信、生物医学中,瞬时频率是一些物理现象的很好描述。Wigner分布是时,频信号分析的有效工具。本文阐述了信号瞬时频率的概念及其定义。论述了用相位差分和用Wigner分布估计瞬时频率的方法。论证了Wigner分布峰值检测可以为高信噪比下线性调频信号提供最佳估计。

The measurement of the instantaneous freqency (IF) of a time-varying signal is of importance to many applications such as seismic, radar, sonar, communication and biomedicine because the IF gives a good description of some physical phenomenon. The Wigner distribution (WD) is a effective tool for time-frequency signal analysis. The concept of IF and its definitions are presented in this paper. The methods for estimating the IF by use of the phase difference and the WD peak privides an optimate for linear FM signal at high sig- nal-to-noise ratios.