Robust Beamforming Based on the Least-Squared Method of Subarrays for Imperfect Antenna Array

Abstract

This paper presents an approach to array beamforming in the presence of array imperfections. The least-squared method of subarrays is used to improve the performance of the optimal beamformer. The proposed beamformer has a constraint that ensures that the desired signal passes through the processor undistorted in the look direction. It is also capable of nulling in the directions of co-channel interference. The simulations are done in the scenarios of white noise and colored noise. A significant performance improvement over the optimal beamformer is achieved in features of low sidelobes, undistorted desired signal, high output SINR and high array gain. Furthermore, the results demonstrate that the least-squared technique of subarrays is robust to array gain perturbation and to strong co-channel interference as compared to the ideal beamformer.