Wireless Energy and Information Transfer Tradeoff for Limited-Feedback Multiantenna Systems With Energy Beamforming

摘要

In this paper, we consider a multi-antenna system where the receiver shouldharvest energy from the transmitter by wireless energy transfer to support itswireless information transmission. In order to maximize the harvesting energy,we propose to perform adaptive energy beamforming according to theinstantaneous channel state information (CSI). To help the transmitter toobtain the CSI for energy beamforming, we further propose a win-win CSIquantization feedback strategy, so as to improve the efficiencies of both powerand information transmission. The focus of this paper is on the tradeoff ofwireless energy and information transfer by adjusting the transfer durationwith a total duration constraint. Through revealing the relationship betweentransmit power, transfer duration and feedback amount, we derive two wirelessenergy and information transfer tradeoff schemes by maximizing an upper boundand an approximate lower bound of the average information transmission rate,respectively. Moreover, the impact of imperfect CSI at the receiver isinvestigated and the corresponding wireless energy and information transfertradeoff scheme is also given. Finally, numerical results validate theeffectiveness of the proposed schemes.