Broadband DOA Estimation Based on Sparse Representation in Spatial Frequency Domain

A novel wide-band Direction-Of-Arrival (DOA) estimation method based on space-frequency sparse representation is proposed to estimate the frequency and DOA of narrow band signal with a wide band receiver. The over-complete dictionary is constructed by using space-frequency to replace the 2D combination of frequency and azimuth. Although the length of constructed dictionary equates to the length of narrow signal DOA estimations dictionary, it could cover the whole unambiguous frequency. The precise frequency of signal is estimated through frequency spectral searching, and the frequency covariance matrix is constructed based on the position of frequency spectral peak. Then DOA can be obtained using the sparse representation of the large eigenvectors, which are coming form the frequency peak covariance matrixs Eigenvalue Decomposition (ED). The proposed method has a higher precision in the low Signal to Noise Ratio (SNR), and the number estimated can be much more than the array numbers. The experiment results indicate that the proposed method is correct and effective to estimate the frequency and DOA of narrow signal for wide-band receiver.