Improved angular resolution of beamspace MUSIC for finding directions of coherent sources

Beamspace MUSIC (multiple signal classification) of forward-backward spatial smoothing are used to estimate the directions of coherent arrivals. Coherence are often encountered in sonar, radar, or mobile communications. Such combination can be degraded when the source signals become coherent or strongly correlated. In this paper, we improve angular resolution of beamspace MUSIC by using the forward-backward averaging of a combined signal eigenvectors. The sample covariance matrix computed from the forward-backward spatial smoothing is exploited for an eigen-decomposition. The decorrelation performance of the proposed method is compared to the several methods based on MUSIC and on beamspace MUSIC, in terms of directions of arrival (DOA) estimations, MSEs versus (1) correlation, (2) noise variance and (3) SNRs, probability of resolution to separate closely spaced DOAs