跳频信号的几种Cohen类时频分布性能比较

A Comparison among Several Cohen Class’ Time-Frequency Distributions of Frequency-Hopping Signals

分析了谱图（SPEC）、伪Wigner—Ville分布（PWVD）、平滑伪Wigner-Ville分布（SPWVD）、矩形核分布（RKD）及Choi—willianls分布（CWD）等几种典型Cohen类时频分布核函数的特点，从信号项的保留和交叉项的去除两个方面比较了它们对跳频信号模糊函数的滤波效果，同时从交叉项抑制和时频聚集性两个方面比较了这几种时频分布的性能。理论分析和仿真结果表明，在核函数形式和参数选取适当的情况下，SPWVD在减小交叉项、保持时频聚集性以及抗噪性方面优于其它时频分布，更适于表征跳频信号的时变信息。

Several typical time-frequency distributions of Cohen class ？ spectrogram（SPEC）, pseudo Wign- er-Ville distribution（PWVD）, smoothed pseudo Wigner-Ville distribution（SPWVD）, rectangle kernel distribu- tion （RKD）, Choi-WiLliams distribution （CWD） and their kernel function are discussed in this paper. From the reservation of auto-terms and the removal of cross-terms, their performance is compared on filtering the ambi- guity function of frequency-hopping signals. The theoretical analysis and simulation result shows that on the condition that the types and parameters of kernel function are properly selected, SPWVD is superior to the oth- ers in cross-term reduction, time-frequency concentration and noise suppression. So it is more suitable to the time-frequency analysis of frequency-hopping signals.