Transceiver Design to Maximize the Weighted Sum Secrecy Rate in Full-Duplex SWIPT Systems

This letter considers secrecy simultaneous wireless information and power transfer (SWIPT) in full-duplex (FD) systems. In such a system, FD capable base station (FD-BS) is designed to transmit data to one downlink user and concurrently receive data from one uplink user, while one idle user harvests the radio-frequency (RF) signals' energy to extend its lifetime. Moreover, to prevent eavesdropping, artificial noise (AN) is exploited by FD-BS to degrade the channel of the idle user, as well as to provide energy supply to the idle user. To maximize the weighted sum of downlink secrecy rate and uplink secrecy rate, we jointly optimize the information covariance matrix, AN covariance matrix, and receiver vector, under the constraints of the sum transmission power of FD-BS and the minimum harvested energy of the idle user. Since the problem is nonconvex, the log-exponential reformulation and sequential parametric convex approximation (SPCA) method are used. Extensive simulation results are provided and demonstrate that our proposed FD scheme extremely outperforms the half-duplex scheme.