Robust high-resolution direction-of-arrival estimation via signal eigenvector domain

A robust high-resolution direction-of-arrival (DOA) estimation approach for coherent/noncoherent sources is presented. The approach is based on the fact that the signal eigenvectors of the covariance matrix are a linear combination of the direction vectors that contain the DOA information. By applying a high-resolution frequency estimation algorithm to an element sequence from a combination of the signal eigenvectors, the approach achieves better performance at low SNR than the conventional methods. It is shown that the improvement in performance increases with the number of snapshots. For example, the resolution improvement of the proposed signal eigenvector domain approach over spatial-smoothed minimum-norm is about 2.5 dB and 7 dB for 20 and 100 snapshots, respectively