Interference Suppression in Gnss Receivers

Antenna arrays with space-time adaptive processing (STAP) have been widely used in Global Navigation Satellite System (GNSS) to suppress interference in spatial domain as well as temporal domain, its performance depends on digital beamforming algorithms. In this paper, we propose a joint adaptive beamforming algorithm which produces nullings in the directions of interference while simultaneously maximizing carrier-to-noise ratio (C/N0) of post-correlation signal. Firstly, the interferences are cancelled by using subspace orthogonal projection. Then the maximum C/N0 constraint algorithm is employed to enhance the post-correlation signal. Meanwhile, a simple estimation approach about numbers of interferences is introduced. Finally, simulations demonstrate that using our adaptive algorithm, STAP can effectively suppress the strong interference and improve the capturing capability of GNSS.