Trust-Degree-Based Secure Relay Selection in SWIPT-Enabled Relay Networks

In this paper, we investigate the trust-degree-based secure relay selection in simultaneous wireless information and power transfer (SWIPT)-enabled relay networks. In particular, we optimize the interference power by selecting the appropriate relay and time division ratio on the condition of both the secure transmission and trust degree. First, by applying the security capacity constraint, we derive the expressions of the time division ratio and relay interference power concerning the trust degree. Then, we discuss the different results for different trust degrees and determine the set of trust degrees to guarantee secure communications. Finally, according to the different trust degrees, we compute the needed interference power for each relay and make a selection to obtain the optimal performance under relay networks. Simulation results show that with the known trust degree the proposed algorithm obtains the appropriate relay and time division ratio, reduces energy consumption, and guarantees an achievable security rate.