Secrecy Spectral Efficiency Fairness among Multi-Cells in SWIPT-Enabled Cooperative NOMA Transmissions

This paper investigates the physical layer security in simultaneous wireless information and power transfer (SWIPT)-enabled cooperative non-orthogonal multiple access (NOMA) transmissions. Taking the malicious eavesdropper into account, we study on the problem of artificial noise (AN)-aided transceiver optimization. To guarantee the quality of service (QoS) at cell-edge users and promote the average performance of system, we consider the multi-cell beam-forming (MCBF) and formulate the problem of maximizing the secrecy spectral efficiency fairness (SSEF) among multiple coordinated cells. As the formulated problem is nonconvex and difficult to solve with existing methods, we apply the semi-definition relaxation (SDR) technique and propose an iterative algorithm based on successive convex approximation (SCA) for complexity reduction. Furthermore, we analyze the complexity of the proposed algorithm. Finally, simulations results demonstrate our analysis and illustrate the validity of AN-aided MCBF transmission scheme.