Diagonal Loading Level Estimation For Robust Beamforming

Often in practice, the knowledge of the array steering vector is imprecise, the Capon beamformer may suffer considerable performance degradation. In order to improve the robustness of the Capon beamformer, diagonal loading has been a popular method. However, for most of these methods, it is not clear how to choose the appropriate diagonal loading level. Based on our cost function, an iterative search method for choosing the loading value is proposed. Using the appropriate diagonal loading level found through the search process, the effectiveness and better performance comparing with other methods have been showed via a number of numerical examples