New Approaches for Construction of Time-Frequency Kernels

The time-frequency distributions of Cohen's class produce cross-terms for mono-component nonlinear frequency modulated signal or multi-component signal, which make it diffcult to analyze and represent theauto-terms of the signal. In this paper, the new approachesfor construction of time-frequency kernels are presentedbased on the Wigner-Ville distribution (WVD) and the LWigner-Ville distribution (LWVD) in order to reduce thecross-terms. Two kinds of Phase adjust function (PAF),namely, the Exponential PAF (EPAF) and the ComplexLag PAF (CLPAF) are designed, then combining themwith WVD and LWVD, the new time-frequency kernelswith four structures-WVD-EPAF, WVD-CLPAF, LWVDEPAF and LWVD-CLPAF are constructed, and the crossterms induced by the nonlinearity of the signal can bedeleted or reduced. Simulated results demonstrate the validity of the methods proposed.