A new robust quadratic constraint beamforming against array steering vector errors

A new robust adaptive beamforming based on quadratic constraint is presented; it is a robust extension of Capon's minimum variance distortionless response (MVDR) beamforming algorithm. The quadratic constraint is added to the weighted least squared error between the desired and the actual beam patterns over a small region near the array steering direction, which makes the array less sensitive to steering vector errors and nonstationary data snapshots. Thus, robustness is achieved. Furthermore, a computationally efficient data dependent approach based on eigenvalue decomposition is proposed to determine the robust control parameter in this algorithm properly; computer simulations and sonar experimental data indicate that this method is effective and applicable in practice.