Secure transmission for energy harvesting relay networks with the destination self-protection mechanism

Abstract

In this paper, we investigate the physical layer security (PLS) of an energy harvesting (EH) cooperative network with the destination self-protection mechanism. More specifically, we consider a cooperative transmission scenario in which a source communicates with a destination through a wireless-powered relay using power splitting (PS) protocol in the presence of an eavesdropper. To degrade the wiretap channel, the destination is operated in full-duplex (FD) to achieve simultaneous information reception and jamming transmission. Taking into account the residual self-interference (SI) at the destination, the non-convex secrecy rate maximization problem is formulated to jointly optimize the PS factor and power allocation of source and destination. Due to the non-convexity of the joint optimization, a low complexity iterative algorithm based on the alternative search method and difference of convex functions (DC) programming is proposed. The original problem is first decomposed into two sub-problems with the fixed transmission power or PS factor. Since the decomposed two sub-problems are still non-convex, we utilize the DC programming to obtain the local solutions of the two sub-problems. Then the global solutions can be obtained by the alternative search method. Simulation results present that the proposed scheme has fast convergence. Comparing with other conventional schemes, the proposed scheme has the best security performance.