Adaptive arrays and sidelobe cancellers - A perspective

An elementary discussion of the technique of adaptive arrays and sidelobe cancellers, as used to eliminate directional interference, is given. The basis of these techniques is the determination of the adaptive coefficients of the covariance matrix. Three major methods of implementing processors to control an adaptive array are outlined: the sample matrix inversion technique, the correlation loop, and the modified random search algorithm. Some of the main limitations in applying adaptive array techniques are pointed out. These include sensitivity to number of directional noise sources, decorrelation of the jamming signal in the main channel with respect to the same signal in an auxiliary channel, and multipath effects. A guide to the literature on adaptive arrays is given and directions of recent work are discussed.