Robust adaptive beamforming against significant angle mismatch

In this paper, a new approach to robust adaptive beamforming in the presence of significant direction-of-arrival (DOA) mismatch is presented. The proposed method consists of two steps. First, the desired steering vector against large DOA mismatch is estimated. Then, the beamformer weight vector is obtained by applying the general-rank signal model-based robust beamforming approach to achieve robustness against arbitrary steering vector errors. Different from existing robust adaptive beamforming algorithms based on the uncertainty set of the steering vector, the proposed approach does not make assumptions on the size of the uncertainty set. Numerical examples are presented to demonstrate the performance of the proposed approach in different hypothetical scenarios.