Performance Investigation of Robust Linearly Constrained Minimum Variance Beamforming for Uniform Circular Array

The performance of beamformer deteriorates due to signal mismatch caused by look direction disparity and scattering. To overcome this issue, a modified robust Linearly Constrained Minimum Variance(LCMV) beamforming method using variable optimal diagonal loading is addressed in this paper. It uses null constraints to reject interference signals and diagonal loading to increase the robustness of the beamformer against any steering vector mismatch. The performance of the proposed method has been observed for several steering vector mismatch condition. In every scenario, it achieves higher output signal to interference plus noise ratio (SINR) at lower snapshots than the existed beamforming method. Simulations are performed in MATLAB for finding out the performance of the proposed method.