Secure Transmission of Cooperative Zero-Forcing Jamming for Two-User SWIPT Sensor Networks

In this paper, the secrecy performance of the two-user simultaneous wireless information and power transfer (SWIPT) sensor networks is studied and a novel secure transmission scheme of cooperative zero-forcing (ZF) jamming is proposed. The two sensors opportunistically conduct the SWIPT and cooperative ZF jamming, respectively, where the energy required for jamming the eavesdropper is provided by the SWIPT operation so as to keep the energy balance at the sensors in the long run. By deriving the exact closed-form expressions of the secrecy outage probability and the secrecy throughout, we provide an effective approach to precisely assess the impacts of key parameters on the secrecy performance of the system. It has been shown that the secrecy outage probability is a monotonically increasing function of the growth of secrecy rate ([Formula: see text]), and a monotonically decreasing function of the increase of the transmit signal-to-noise ratio ([Formula: see text]), and energy conversion efficiency ([Formula: see text]). Furthermore, the secrecy throughput could be enhanced when [Formula: see text] increases, which becomes especially obvious when a large [Formula: see text] is provided. Moreover, the existence of an optimum [Formula: see text] maximizing the secrecy throughput is depicted, which also grows with the increase of [Formula: see text]. Simulations are provided for the validation of the analysis.