Robust beamforming against mismatched signal steering vector using ellipsoidal constraints

In practical array signal processing environment steering vector uncertainties are present which degrade the performance of adaptive beamforming significantly. The steering vector uncertainty occurs primarily due to mismatch in the direction of signal of interest (SOI). This article presents an efficient approach to enhance the performance of adaptive beamforming in the presence of uncertainty in the steering vector of SOI. The proposed method is based on diagonal loading and utilizes the ellipsoidal constraints to reformulate the optimization problem. The output signal to interference noise ratio (SINR) obtained from the proposed beamforming method shows its superiority over the existing robust beamforming methods. Moreover, the proposed beamforming method accurately estimates the power of SOI.