AN ADAPTIVE ORIENTATIONAL BEAMFORMING TECHNIQUE FOR NARROWBAND INTERFERENCE REJECTION

In this paper, we investigate and extend the linearly constrained minimum variance (LCMV) algorithm for conventional wideband beamforming system to the recently proposed orientational beamforming (OBF) system. An orientational LCMV (O-LCMV) algorithm is proposed. It is constructed on the orientation dimension, and an orientational constraint instead of directional constraint is used to guarantee an orientational gain for the desired signal. This perfectly solves the problem of rejecting an interference arriving from the same direction as the desired signal, which current adaptive directional beamforming algorithms cannot handle. Numerous simulations show that the O-LCMV algorithm for the OBF system works effectively regardless of the number of narrowband interferences (NBIs) or their DOAs if the NBIs have the same center frequency. As the number of different center frequencies of the NBIs increases, the performance degrades slightly.