Wireless Power Transfer-Based Multi-Pair Two-Way Relaying With Massive Antennas

• Published in: IEEE transactions on wireless communications Vol. 16; no. 11; pp. 7672 - 7684
• Main Authors: Wang, Xinhua, Liu, Ju, Zhai, Chao
• Format: Journal Article
• Language: English
• Published: IEEE 01.11.2017
• Subjects: Antenna arrays; Energy harvesting; massive MIMO; MIMO; multi-pair two-way relaying; power-splitting; Relay networks (telecommunications); Wireless communication; wireless power transfer; Wireless sensor networks
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2017.2753223

In this paper, we study a multi-pair two-way relay network consisting of two groups of user equipments (TIEs), who want to exchange information through a common relay equipped with massive antennas. In the multiple access phase, the TIEs transmit information to the relay using the energy harvested in the last time block, and the relay decodes information using zeroforcing (ZF) or maximal ratio combining (MRC) technique. In the broadcasting phase, the relay performs simultaneous wireless information and power transfer (SWIPT), and each TIE receives energy and information using the power-splitting scheme. Due to the channel hardening effect of the large-scale antenna array, the harvested energy of each TIE in each time block is asymptotically constant. Based on the derived achievable rates of TIEs, a multi-objective optimization problem (MOOP) is formulated to maximize the achievable rates of all the pairs. Through solving the MOOP, the power-splitting ratios of TIEs can be determined in closed-form for the ZF-based relaying. For the MRC-based relaying, a two-stage iterative Pareto improvement algorithm is proposed to achieve the Pareto optimality. Simulation results are presented to validate our theoretical analysis and verify the efficiency of our proposed algorithm in improving the system rate.