Physical Layer Security Enhancement for Satellite Communication among Similar Channels: Relay Selection and Power Allocation

To implement secure communication among similar channels for satellite communications, a secure communication model based on collaboration with the interference relay of the satellite physical layer is proposed in this paper. Relay selection and power allocation are further studied to enhance the security performance of the satellite communication system based on the model. The relay selection standard under known instantaneous channel state information (CSI) and statistical CSI conditions is theoretically derived, thereby minimizing the secrecy outage probability(SOP). In addition, the power allocation factor is optimized based on the minimization of the SOP. Moreover, a power allocation method based on the statistical CSI is presented. The SOP performance of each relay selection criterion and power allocation scheme are analyzed.