Secrecy Rate Maximization for MISO System with Energy Harvesting and Eavesdroppers

In this paper, we investigate the secrecy rate maximization problem for a multi user multiple-input single-output (MISO) broadcast interference communication system with simultaneous wireless information and power transfer (SWIPT), in the presence of external eavesdroppers. Assuming that the channel state information is perfectly known at the transmitter, the main aim is to maximize the secrecy rate of the system under signal to interference plus noise ratio (SINR), energy harvesting (EH) and total transmit power constraints. The original secrecy rate maximization problem is non-convex in terms of transmit beamforming matrix and power splitting ratios, usually solved via semi-definite relaxation. In order to circumvent this non-convexity issue, we propose a concave-convex procedure (CCCP) based iterative algorithm, which provide a local maximum for the secrecy rate maximization. Simulation results are presented to validate the effectiveness of our proposed algorithm. It is demonstrated that our proposed CCCP based iterative algorithm achieves higher secrecy rate and has a lower computational complexity as compared to the conventional SDR technique.