Advances in Electrical and Electronic Engineering
In this paper, we evaluate system performances of a multi-hop relay protocol with presence of an active eavesdropper. In the proposed protocol, a source attempts to transmit its data to a destination with assistance of multiple intermediate relays. From the eavesdropping Channel State Information (CSI) estimated, the source and relays adjust their transmit power so that the eavesdropper cannot overhear the transmitted data. Moreover, to enhance throughput for the proposed system, Non-Orthogonal Multiple Access (NOMA) technique with a simple power allocation is also proposed. We derive exact closed-form expressions of the Outage Probability (OP) and throughput for the data transmission over Rayleigh fading channel. In addition, when the CSI estimation is imperfect, Intercept Probability (IP) at the eavesdropper is derived. Finally, Monte Carlo simulations are presented to verify the theoretical derivations.