Joint time switching and power allocation in large-scale MISO OFDM systems with wireless powered relay

Abstract

Wireless power transfer is an effective way to prolong the operation time of energy-constrained wireless networks. This paper addresses the achievable rate optimization of a large-scale multiple input single output (MISO) orthogonal frequency division multiplexing (OFDM) system with a wireless powered decode-and-forward (DF) relay. The source is equipped with a large numbers of antennas, and maximum ratio transmission beamforming is used for both power transfer and information transmission from the source to the relay. The power allocation (PA) and time-switching (TS) ratios of power transfer and information transmission from the source to the relay as well as information transmission from the relay to the destination are jointly optimized to maximize end-to-end transmission rate, and thus a jointly optimal TS and PA scheme is proposed. Computer simulation results have validated the optimality of the proposed scheme.