DOA estimation of nonstationary sources with time-frequency maximum likelihood method

Direction finding of nonstationary signals by using antenna array is of growing interest in the signal processing community. We develop a time-frequency maximum likelihood method based on the cross Pseudo Wigner-Ville Distributions (PWVDs) between the array signal vector and the satellite sensor output to obtain the DOA estimates. Compared with the methods based on the STFD (Spatial Time-Frequency Distributions) matrices, the proposed method can make full use of the crossterm TFDs between sources, and signal selective direction finding can be realized with much simpler computation. Moreover, the proposed method can handle signals with the same time-frequency signature. Numerical simulations are provided to demonstrate the validity of the method.