Cluster-based Wireless Energy Transfer for Low Complex Energy Receivers

TL;DR

This paper introduces a cluster-based scheduling and channel estimation method for wireless energy transfer systems, improving energy delivery fairness and efficiency to low-complexity receivers.

Contribution

It presents a novel channel estimation and clustering approach that enhances energy transfer fairness and efficiency in low-complexity wireless energy systems.

Findings

Significant performance gains over benchmark schemes.

Fair and opportunistic scheduling among energy receivers.

Effective channel estimation with RSSI feedback.

Abstract

This paper proposes a novel channel estimation method and a cluster-based opportunistic scheduling policy, for a wireless energy transfer (WET) system consisting of multiple low-complex energy receivers (ERs) with limited processing capabilities. Firstly, in the training stage, the energy transmitter (ET) obtains a set of Received Signal Strength Indicator (RSSI) feedback values from all ERs, and these values are used to estimate the channels between the ET and all ERs. Next, based on the channel estimates, the ERs are grouped into clusters, and the cluster that has its members closest to its centroid in phase is selected for dedicated WET. The beamformer that maximizes the minimum harvested energy among all ERs in the selected cluster is found by solving a convex optimization problem. All ERs have the same chance of being selected regardless of their distances from the ET, and hence, this scheduling policy can be considered to be opportunistic as well as fair. It is shown that the proposed method achieves significant performance gains over benchmark schemes.