Robust minimum dispersion distortionless response beamforming against fast-moving interferences

Abstract

The recently proposed minimum dispersion distortionless response (MDDR) beamformer is able to improve the reception of non-Gaussian signals over the minimum variance distortionless response (MVDR) beamformer. However, the performance of the MDDR beamformer degrades in the presence of fast-moving interferences. To suppress such an interference, a robust beamformer against fast-moving interferences based on the minimum dispersion (MD) criterion is proposed, which provides a continuous deep null sector over a predefined range of dynamic angle-of-arrival (AOA). The designed beamformer ensures that the output is minimized in terms of dispersion and the average power over the dynamic AOA is zero via a quadratic constraint. In order to reduce the computational load, the optimization problem with a quadratic constraint is relaxed to its counterpart with a linear constraint. This allows us to devise an efficient beamforming approach, namely, gradient projection algorithm. Numerical results are provided to demonstrate that the developed beamformer can suppress the strong fast-moving interferences effectively.