基于多谱图叠加阈值的抑制WVD交叉项的新方法  

A New Method to Suppress Cross-Terms of WVD via Thresholding Superimposition of Multiple Spectrograms

作　　者：李雨青[1] 水鹏朗[2] 林英[1] 

机构地区：[1]西安电子科技大学理学院数学系,西安710071 [2]西安电子科技大学雷达信号处理重点实验室,西安710071

出　　处：《电子与信息学报》2006年第8期1435-1438,共4页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(60272058);国家优秀博士学位论文作者专项基金(200139);教育部高校青年教师奖基金资助课题

摘　　要：本文提出了一种抑制Wigner-Ville分布(WVD)交叉项的新方法。首先对多幅具有不同时-频分辨率的谱图进行叠加,然后对叠加结果进行阈值处理,确定WVD自项在时频平面的支撑区域。最后,用该区域的示性函数乘以WVD得到一个新的时频分布。不同于传统的抑制交叉项的核函数方法,该方法抑制交叉项的同时,保持WVD了高时频聚集性。实验结果表明,该方法对由多个LFM信号构成的多分量信号和非线性调频信号都非常有效。In this paper, a new method is proposed to suppress the cross-terms of Wigner-Ville Distribution （WVD）, which is based on thresholding the superimposition of multiple spectrograms. First, the spectrograms with different time-frequency resolutions are superimposed and then the superimposition is thresholded to localize the auto-term support region of the WVD. Secondly, the WVD is multiplied by the indication function of the region. In this way, a new Time-Frequency Distribution （TFD） is obtained. Unlike the traditional kernel function methods to suppress cross terms, our method not only reduces the interfering cross-terms but also preserves the superb time-frequency concentration of the WVD. The experimental results show that the method is very effective for both the multicomponent signals consisted of the LFM＇s and nonlinear frequency modulation chirp signals.

关 键 词：WIGNER-VILLE分布 谱图 交叉项 自项 阈值处理 

分 类 号：TN911.7[电子电信—通信与信息系统]