A new robust beamforming approach in a coherent signal environment

Since the standard Capon beamforming is susceptible to the steering vector (SV) mismatch of the signal of interest (SOI) and other array response in a coherent signal environment, a beamforming algorithm using SVD-Toeplitz direction of arrival (DOA) estimation, interference-plus-noise covariance matrix reconstruction and steering vector estimation is proposed. Based on uniform linear array model, the process of this new algorithm is divided into four steps. Firstly, the spatial spectrum of the received signal is obtained by using a SVD-Toeplitz DOA estimator. Secondly, the acquired spatial spectrum is used to reconstruct the interference-plus-noise covariance matrix. Thirdly, the desired signal steering vector is obtained by using the orthogonal component of the mismatch between the true and presumed steering vector. At last, the weight vector can be computed. Simulation results demonstrate the proposed approach offers effective coherent interference suppression capability and improve the robustness and output signal-to-interference-and-noise ratio (SINR) of the array.