Robust Simultaneous Wireless Information and Power Transfer in Beamspace Massive MIMO

• Published in: IEEE transactions on wireless communications Vol. 18; no. 9; pp. 4199 - 4212
• Main Authors: Zhu, Fengchao, Gao, Feifei, Eldar, Yonina C., Qian, Gongbin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antennas; Array signal processing; Beamforming; beamspace; Channel estimation; Computational geometry; Computer simulation; Convexity; Energy harvesting; Interference; massive MIMO; MIMO (control systems); MIMO communication; non-convex optimization; Optimization; Power management; Power transfer; robust beamforming; Robustness; Scaling factors; Simultaneous wireless information and power transfer (SWIPT); Wireless communication
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2019.2916405

We investigate the worst-case robust beamforming for simultaneous wireless information and power transfer in a multiuser beamspace massive multiple-input multiple-output (MIMO) system. The objective is to minimize the transmit power of the base station subject to the individual signal-to-interference-plus-noise ratio and the energy-harvesting constraints under imperfect channel state information. Instead of directly resorting to semi-definite relaxation, we convert the initial non-convex optimization to a power allocation problem, which greatly reduces the computational complexity. The beamforming vectors are proven to be scaled versions of the estimated channels. The optimal scaling factors are then derived in closed-form. The simulations demonstrate that the proposed robust beamforming method achieves the globally optimal point for the initial design when the channel estimation errors are small while leads to satisfactory performance when the channel estimation errors are large.