Detection and estimation of Doppler signal using HHT marginal spectrum

A new method based on Hilbert-Huang transform (HHT) marginal spectrum is proposed to detect the Doppler signal and estimate the Doppler shift in this paper. This method first iteratively decompose the Doppler signal into a number of intrinsic mode functions (IMFs) Which are monocomponent. Then Hilbert transform is applied to each IMF to calculate Hilbert spectrum, and HHT marginal spectrum is obtained by integrating Hilbert spectrum with respect to time. The emergence of the Doppler signal can be detected in terms of the maximum amplitude of HHT marginal spectrum larger than the preset threshold. The amount of Doppler shift is estimated as the difference between the radar center frequency and the frequency, at which the band pass spectrum of the received signal is centered. Simulation experiments show that HHT marginal spectrum is a promising approach for the detection and estimation of Doppler signal.