Beam Pattern Synthesis in the Presence of Interference and Multipath

In this paper, an improved beampattern synthesis technique based on generalized sidelobe canceller (GSC) structure is proposed. Constrained optimization algorithm is used to control the beampattern from the main beam. Instead of selecting the blocking matrix in the noise subspace which is orthogonal to the signal-plus-interference subspace, we use the cyclostationary property of the transmitting signals to ensure that the blocking matrix spans the interference-plus-noise subspace. This can help us to get a better control of the beampattern, especially in the interference-limited and time-varying environment and when the interference is close to the look direction. We also consider the case when multipath signals exist along with the desired signal, and put forward an improved structure to solve this problem. Numerical results show that compared with other GSC-based structures, our proposed beampattern synthesis technique is able to reject strong directional interferences and multipath signal.