Joint Optimization of AN-Aided Transmission and Power Splitting for MISO Secure Communications With SWIPT

For simultaneous wireless information and power transfer (SWIPT), secure communication is an important issue. In this letter, we consider a wireless multiple-input-single-output secure communication system with SWIPT overheard by multiple multi-antenna eavesdroppers. In the system, a transmitter employs artificial noise (AN)-aided transmission and a legitimate receiver employs power splitting (PS) to harvest energy. Our objective is to jointly design AN-aided transmission and PS scheme which maximizes achievable secrecy rate under transmit power constraint and energy harvesting constraint. We propose to include an equality constraint to convert the constraint on information rate from transmitter to eavesdroppers into linear matrix inequalities. Replacing the equality constraint with a convex constraint and a concave constraint, we propose to employ constrained concave convex procedure based algorithm to find a local optimum of the problem. Simulation results demonstrate that the proposed joint optimization of AN-aided transmission and PS scheme outperforms the non-AN-aided one.