Adaptive beamforming for large arrays in satellite communications

In this paper, we focus on adaptive beamforming applied to a geostationary satellite system working in the Ka-band. Given a user of interest, all users of the system using the same frequency appear as jammers. Unknown sources might also interfere with the system. Adaptive beamforming provides the system with the suppression of interferences. Given the high number of sensors, computational load must be accounted. Our goal is therefore to design adaptive beamformers that yield the best signal-to-interference-plus-noise ratio (SINR) at lower possible cost. We present in this paper a reduced-rank adaptive beam- former: the iterative Conjugate Gradient (CG), and we compare its performances to those of a new adaptive beamformer using orthogonal projections and prior knowledge of the directions-of-arrival (DOA) of the sources.