Two-dimensional beamforming using a frequency domain complex Least Mean-Squares (LMS) adaptive filter

Abstract

The complex LMS adaptive algorithm developed by Widrow [Ref. 1] is used in the frequency domain to estimate the azimuth and elevation angles of a plane wave incident upon a planar array. The complex LMS algorithm is applied to two cases. The first case is a passive detection problem. The second case is a pulse communication problem. In both cases, complex weights are determined using the complex LMS algorithm which cophase all of the output electrical signals from -the planar array. Three versions of the complex LMS algorithm are studied and their performances are compared.