广义S变换及其在复杂辐射源信号分析中的应用

Generalized S-transform and Its Application to Analysis of Complex Emitter Signals

该文提出一种基于修正Hermite函数的广义多窗S变换方法,并将之应用于复杂多分量辐射源信号的瞬时频率结构分析。该方法通过引入频率尺度因子修正正交Hermite函数,将多窗时频分析方法推广到S变换中,使得改进后的广义S变换既保留了多分辨特性,又很好地解决了高频区存在的频率分辨率低、易受噪声干扰等问题。与S变换和原始多窗时频分析方法相比,该方法在瞬时频率估计精度和时频聚集性等方面均有明显改善,具有很好的工程应用前景。

A new method called generalized Multi-Window S-Transform （MW-ST） is proposed for blind Instantaneous Frequency （IF） analysis of complex emitter signals. The high concentration is achieved by employing the modified Hermite function. In this distribution, the orthogonal Hermite function is improved by utilizing a frequency parameter. Therefore, the multi-window method can be introducing to S-transform. The generalized MW-ST maintains the multi-resolution characteristics of the ST and improves the frequency resolution in high frequency region. Comparing with the origin S transform and the multi-window method, the proposed method can effectively improve the accuracy of the IF estimation and the time-frequency concentration. So it has the good prospects for engineering applications.