Generalized time-frequency distributions for multicomponent polynomial phase signals

The conventional time-frequency distributions for multicomponent polynomial phase signals (PPS) generally suffer from interference terms, which will obscure the true location of the auto-components in the resulting time-frequency distributions. In this paper, three schemes for designing the generalized time-frequency distributions for multicomponent PPS based on the matched-phase principle are presented, and they are illustrated as follows:(1)the scheme based on the Wigner-Ville distribution (WVD) and the L-Wigner-Ville distribution (LWVD);(2)the scheme based on the fractional matched-phase principle;(3)the scheme based on the complex lags. The interference terms induced by the nonlinearity of the signals can be suppressed; for multicomponent signals, the CLEAN technique is adopted to filter out each component by a band-pass filter, and the interference terms between different components can be suppressed (eliminated). The new generalized time-frequency distributions are superimposed to yield a high-readability representation.