Secrecy rate beamforming for multi-cell SWIPT networks

Considering a multicell network for secure wireless information and power transfer, this paper studies the joint design of transmit beamformers at the base stations (BSs) and receive signal splitting ratios at the end users' equipment (UEs). The primary concern in this work is the network internal security, where there may be a single multi-antenna eavesdropper who eavesdrop on the received signal of any user. The objective is to maximize the minimum secrecy user rate under BS transmit power and UE minimum harvested energy constraints. New path-following algorithm is proposed for computational solution of the difficult nonconvex optimization problem. Each iteration involves one simple convex quadratic program (QP). Numerical results confirm that the proposed algorithm converges quickly after few iterations and the secrecy rate performance is close to that of normal rate in the absence of eavesdropper.