The Application Of Diagonal Loading In Adaptive Beamforming

Adaptive array is widely used in radar and communication system , the simplest means to test the performance of the adaptive array system is to inspect the adaptive beam pattern . However , in concrete application , there exist errors between the real and ideal signal environment, which can cause performance degradation in adaptive beam pattern . Therefore , there is a need for investigating the algorithm of robust adaptive beamforming .To solve the problem of the performance degradation in adaptive beam pattern under finite snapshot condition, Calson proposed the algorithm of diagonal loading . An efficient method to determine the diagonal loading value is introduced in this paper , it can be seen from the result of simulation that this method can lower the height of adaptive beam pattern, and has no effect on nulling depth of the interference .The ultra-low sidelobe technique in large linear array is also analyzed in this paper, in order to get the ultra-low sidelobe , amplitude tapering is often used , but under finite snapshot condition , diagonal loading is required .In the end , the diagonal loading in high rank signal environment is briefly introduced in this paper.