Hybrid wavelet-Hilbert-Huang spectrum analysis

Empirical mode decomposition (EMD) is a new method pioneered by Huang et al. for non-linear and non-stationary signal analysis. Signals are adaptively decomposed into several zero-mean amplitude modulation-frequency modulation (AM-FM) components. Each AM-FM subsignal has well defined instantaneous frequency (IF) called intrinsic mode functions (IMFs). This paper proposes a wavelet packet based method, to increase the band pass filtering ability of the EMD and this method is illustrated for simulation data of AM-FM signals and the results of IF estimation of signals are shown through both the Hilbert transform and the Teager energy operator (TEO).