Transceiver Optimization in Full Duplex SWIPT Systems with Physical Layer Security

Abstract

To meet the requirements of energy saving, high security and high speed for the next generation wireless networks, this paper investigates simultaneous wireless information and power transfer (SWIPT) in full duplex systems taking the physical layer security into account. Specifically, we consider a full duplex wireless system where a full duplex base station (FD-BS) communicates with one downlink user and one uplink user simultaneously, and one idle user also scavenges the radio-frequency (RF) energy broadcasted during the communication for future use. Since the idle user has great potential to intercept the downlink information, we assume that FD-BS exploits the artificial noise (AN), which is another energy source to idle user, to prevent it. The imperfect self-interference cancellation at the FD-BS is considered and the zero forcing (ZF) receiver is adopted to cancel the residual self-interference. Then, the optimal transmitter design at FD-BS are derived to maximize the weighted sum rate of downlink secure and uplink transmission, subject to constraints that the transmission power at FD-BS is restricted and the minimal amount of harvested energy at idle user is guaranteed. The perfect full duplex and half duplex schemes are also introduced for comparison. Extensive simulation results are given to verify the superiority of our proposed full duplex scheme.