Wireless Energy and Information Transfer Tradeoff for Limited Feedback Multi-Antenna Systems with Energy Beamforming

TL;DR

This paper explores the balance between wireless energy transfer and information transmission in multi-antenna systems, proposing adaptive beamforming and feedback strategies to optimize energy harvesting and data rates under various conditions.

Contribution

It introduces a novel tradeoff analysis framework with adaptive energy beamforming and a win-win CSI feedback strategy for improved wireless energy and information transfer.

Findings

Proposed schemes maximize average information rate under energy transfer constraints.

Feedback strategy improves efficiency of power and information transmission.

Numerical results validate the effectiveness of the proposed methods.

Abstract

In this paper, we consider a multi-antenna system where the receiver should harvest energy from the transmitter by wireless energy transfer to support its wireless information transmission. In order to maximize the harvesting energy, we propose to perform adaptive energy beamforming according to the instantaneous channel state information (CSI). To help the transmitter to obtain the CSI for energy beamforming, we further propose a win-win CSI quantization feedback strategy, so as to improve the efficiencies of both power and information transmission. The focus of this paper is on the tradeoff of wireless energy and information transfer by adjusting the transfer duration with a total duration constraint. Through revealing the relationship between transmit power, transfer duration and feedback amount, we derive two wireless energy and information transfer tradeoff schemes by maximizing an upper bound and an approximate lower bound of the average information transmission rate, respectively. Moreover, the impact of imperfect CSI at the receiver is investigated and the corresponding wireless energy and information transfer tradeoff scheme is also given. Finally, numerical results validate the effectiveness of the proposed schemes.