Simultaneous Wireless Information and Power Transfer in Cellular Two-Way Relay Networks With Massive MIMO

In this paper, we study an energy-harvesting cellular two-way relay network with massive multiple-input multiple-output, where multiple energy-harvesting mobile stations (MSs) communicate with a base station (BS) via an energy-harvesting relay station (RS). A signal space alignment (SSA) based simultaneous wireless information and power transfer (SWIPT) protocol is proposed for efficient energy harvesting and information exchange. We analyze the performance of the proposed SSA-SWIPT scheme, and derive closed-form expressions for the asymptotic signal-to-interference-plus-noise ratios and the achievable sum-rate when the numbers of antennas at the BS and the RS go large simultaneously. We also investigate the optimal power splitting ratios at the RS and the MSs to maximize the achievable sum-rate. Numerical results are provided to verify the analysis and it is shown that employing massive antennas can improve the efficiencies of wireless energy harvesting and information transmission.