Secure Semi-Blind AF relaying networks using multiple eavesdroppers

In this paper, we investigate a secure semi-blind amplify-and-forward (AF) relaying system over Rayleigh fading channels. We consider a reactive relay selection where the relay is selected based on the highest instantaneous signal-to-noise ratio (SNR) of the second hop. We evaluate the ergodic secrecy capacity using source-assisted jamming (SAJ) and considering that relays act as eavesdroppers. In order to improve the secrecy performance, a direct link between the source and destination is considered. Numerical results are presented to verify the accuracy of the proposed mathematical analysis. Moreover, a comparison between secure semi-blind AF relaying system and secure channel-state-information (CSI)-assisted AF relaying system is performed to further prove the exactness of our analysis. The proposed secure semi-blind AF relaying system has a simpler mathematical analysis and a comparable secrecy performance as compared to secure CSI-assisted AF relaying system.