A new DOA estimation algorithm for wideband signals in the presence of unknown spatially correlated noise

In this paper, a new high resolution direction-of-arrival (DOA) estimation technique is proposed for wideband signals in the presence of spatially correlated noise with unknown covariance matrix. The proposed technique is based on the (matrix) difference between the forward–backward averaged covariance matrix of the observations and the Hermitian of the backward covariance matrix of the observations. This differencing operation eliminates the noise covariance matrix from the difference matrix. The propagator method is then applied to the difference matrix to find the DOA. This proposed technique does not require any initial estimate of the DOAs and is effective for both correlated and partially correlated sources. In this paper, the proposed technique is applied to a uniform linear array and an L-shaped array for both one- and two-dimensional DOA estimation. Simulations results comparing the performance of the proposed method with that of the coherent propagator method are presented.