Robust adaptive beamforming using Doppler property restoral

Diagonal loading (DL) is the most widely used method to improve the robustness of the Capon beamformer in the presence of finite sample effect and/or signal-of-interest (SOI) steering vector mismatch. However, the determination of the optimal DL level is a challenging task. A Doppler property restoral based method is herein proposed for selecting an appropriate DL level to extract a Doppler SOI buried in interferences plus ambient noise. Simulation results are included to illustrate the performance of the proposed user-parameter-free beamformer.