Security beamforming algorithms in multibeam satellite systems

This paper investigates the physical layer security in a multibeam satellite communication system, where each legitimate user is surrounded by one eavesdropper. First of all, an optimization problem is formulated to maximize the sum of achievable secrecy rate, while satisfying the on-board satellite transmit power constraint. Then, two transmit beamforming(BF) schemes, namely, the zero-forcing (ZF) and the signal-to-leakage-and-noise ratio (SLNR) BF algorithms are proposed to obtain the BF weight vectors as well as power allocation coefficients. Finally, simulation results are provided to verify the validity of the two proposed methods and demonstrate that the SLNR BF algorithm outperforms the ZF BF algorithm.