Parameter Estimation of Multi-Component LFM Signals Based on STFT+Hough Transform and Fractional Fourier Transform

T248 separate and estimate the parameters of multi-component linear frequency modulation(LFM) signals in the presence of white Gaussian noise, a new method based on fractional Fourier transform(FRFT) with the help of short-time Fourier transform(STFT) and Hough transform is proposed. The theory of FRFT for estimating the chirp rate of the multi-component LFM signal is analyzed. Pointing out the phenomenon that when the amplitudes of the strong and weak component signals differ greatly, the weak component signal is disturbed by the strong component signal and can not be detected by the search method. This paper analyzes the advantages of using Hough transform after STFT, and then proposes the use of STFT+Hough transform to estimate the chirp to guide FRFT for small-scale search. The parameters of the strong signal components are estimated one by one, and the strong signal are eliminated in the fractional Fourier transform domain by using very narrow band-stop filtering to improve the reliability of the multi-component signal parameter estimation. The effectiveness of this method is verified by computer simulation.