Performance Analysis of Coherent Interference Suppression Schemes by an Adaptive Antenna Array

Abstract: Rejection of coherent interference requires an array consisting of several identical sub-arrays which operates with spatial smoothing algorithms. For the cases in which such array configuration cannot be obtained, other schemes must be employed to decouple the desired signal and the coherent interference. This paper presents a coherent interference suppression scheme, known as, the complementally transformed minimum variance beamformer, and compare its behavior with the ordinary multiple constrained minimum variance beamformer. It should be noted that both schemes need prior knowledge of the direction of arrival of the interferences. The behavior of both interference suppression schemes are evaluated through computer simulation. The simulation results indicate the advantage of the complementally transformed minimum variance beamformer over the ordinary multiple constrained minimum variance beamformer from the point of view of the degree of coherent interference reduction.