抑制维格纳分布交叉项干扰的自谱窗方法

The Self-Spectrum Window (SSW) method of WVD's Interference-Term Suppression

维格纳分布是一种重要的时—频分析方法,但交叉项干扰问题影响了它的推广应用。本文分析了积分核函数的自维格纳分布项和交叉项的正交性质,从而提出一种用真实的自维格纳分布项的函数作为模板与积分核函数作互相关,抑制交叉项的方法。文中建议采用信号的STFT谱作为窗,在时一频平面上处理维格纳分布来实现上述方法,因此,该方法又称为自谱窗法。本文以仿真信号为例,检验了这种方法的效果。

The Wigner-Ville distribution (WVD) is an important mean of time-frequency analysis, but the cross-term interference in WVD has a great influence on its application. In this paper, a method, which is based on the fact that the cross-term and the corresponding pair of auto-terms in integral kernel function are orthonormal, is developed to suppress the cross-term interference. This method uses a real auto-WVD function as template to cross-correlate with the integral kernel function, and also advices to use the STFT spectrum of the signal as a window function to process the WVD in time-frequency plane. So this method can be called as the Self Spectrum Window (SSW) method. The computer simulation confirms the analysis results and indicates that satisfactory time-frequency distribution is obtained.