Analysis of physical layer security performance for satellite communication systems

Due to the openness of the wireless medium and construction of the space-ground integrated information network,satellite communication (SATCOM) systems are facing severe security challenges.Physical layer security technology can guarantee secure satellite communication and effectively prevent the channel from being eavesdropped.By taking into account the space-ground integrated information network,a security performance analysis framework is developed for the SATCOM system with the existence of a ground eavesdropper and a satellite eavesdropper.Based on the Rayleigh fading channel and Shadowed-Rician fading channel,eavesdropping models of two eavesdroppers are provided,respectively.Regarding the non-collusion and collusion strategies employed at eavesdroppers,the exact expressions for average secrecy capacity (ASC) and secrecy outage probability (SOP) are derived under the two strategies,respectively.Simulation results show that a growing transmit power can improve ASC with SOP unchanged at the same time.Reducing the signal noise ratio at the satellite eavesdropper can provide a better secrecy performance for the SATCOM system than decreasing the signal noise ratio at the ground eavesdropper.