Multipath mitigation techniques for nonlinear adaptive beamforming
Peter G. Vouras · 2016
Nonlinear adaptive processing using sparse arrays has received a fair amount of attention in the radar community recently because it is possible to exploit more spatial degrees of freedom for beamforming than a conventional linear processor would allow. However, the practical difficulties of nonlinear adaptive beamforming have received little consideration in the literature. This paper will describe the deleterious impact of multipath on the adapted output of a nested array and show that nulling performance is severely degraded. Insight into the multipath problem for nonlinear adaptive beamforming will be derived by analyzing an optimal beamformer which suppresses multipath residue at the adapted output. In addition, an analysis of the effectiveness of using the physical array elements to perform spatial smoothing for mitigating the residual effects of multipath will be presented.