Receive Beamforming and Resource Allocation for Wireless Powered Non-Orthogonal Multiple Access

This article investigates a wireless powered communication network with non-orthogonal multiple access for collecting data from battery-limited internet-of-things (IoT) devices. To allow various trade-offs in performance and complexity, we design a generalized multi-antenna successive interference cancellation receiver with receive beamforming (BF), power allocation (PA) to devices, and time allocation (TA) optimized toward maximum fairness. We solve the problem in two steps by optimizing the receive BF and PA for a fixed TA and subsequently optimizing the TA. An iterative algorithm and its suboptimal approach are proposed for the BF and PA while a quasiconcave optimization method is adopted for the TA problem by showing its quasiconcave property. Results show that the proposed methods outperform the conventional one with a larger gain for a higher transmit power and greater number of devices.