Time-Frequency Spatial Smoothing MUSIC Algorithm for DOA Estimation Based on Co-prime Array

In this paper, the time-frequency spatial smoothing MUSIC algorithm (TF-SSMUSIC) for DOA estimation based on co-prime array is proposed. The spatial smoothing MUSIC (SSMUSIC) is a typical DOA estimation algorithm based on co-prime array. TF-SSMUSIC replaces SSMUSIC’s data covariance matrix with a time-frequency distribution matrix, which leads to a better DOA estimation performance. By selecting points in the time-frequency domain, not only the signal-to-noise ratio (SNR) can be improved effectively, but the signal interference in different time-frequency domains can be isolated. The improvement of SNR makes TF-SSMUSIC have a more accurate DOA estimation than SSMUSIC in the case of low SNR. Especially, if source signals are separable in the time-frequency domain, TF-SSMUSIC can process them solely. In this way, the angle resolution and the number of predictable source signals can be improved greatly.