Proximal gradient method based robust Capon beamforming against large DOA mismatch

The Capon beamformer has excellent resolution and interference suppression capability but due to various attributes of practical environment such as inaccurate and/or insufficient information about the source, transmission medium and antenna array its performance deteriorates. To enhance its performance various efforts have been devoted and one effective method is presented here. In this paper, a novel and efficient robust Capon beamformer is devised which is based on proximal gradient method (PGRCB) and the robustness is achieved through remodeling the optimization problem of standard Capon beamformer (SCB). In the proposed PGRCB, the proximal gradient method is used to formulate a new optimization problem in order to obtain the optimum weights of the robust beamformer. The proposed method can achieve better performance as compared to some recent methods in the literature and its effectiveness is verified by the simulation results.