A class of robust adaptive beamforming algorithms for coherent interference suppression

Based on the uniform linear array (ULA) and the spatial-smoothing technique, a robust beamforming problem for the reception of coherent signals is addressed and a forward-only (FO) beamformer is proposed based on worst-case optimization by considering both the steering vector and the correlation matrix errors. It is then extended to the forward-backward (FB) case with an improved performance. By introducing a preprocessing matrix, real-valued closed-form solutions are then derived with the same performance as in the FB case, but with much lower computational complexity. Simulations verified the effectiveness of the proposed algorithms.