Many a little Makes a Mickle: Probing Backscattering Energy Recycling for Backscatter Communications

TL;DR

This paper explores energy recycling in full-duplex backscatter communications with multiple devices, proposing an optimization framework that significantly improves energy efficiency by joint scheduling, beamforming, and reflection control.

Contribution

It introduces a novel energy recycling mechanism among backscatter devices and develops an iterative algorithm to optimize energy efficiency under practical constraints.

Findings

Proposed algorithm outperforms benchmark algorithms in energy efficiency

Energy recycling among devices enhances overall system performance

Joint optimization improves throughput and reduces energy consumption

Abstract

In this paper, we investigate and analyze full-duplex-based backscatter communications with multiple backscatter devices (BDs). Different from previous works where only the energy from the energy source is harvested, BDs are also allowed to harvest energy from previous BDs by recycling the backscattering energy. Our objective is to maximize the total energy efficiency (EE) of the system via joint time scheduling, beamforming design, and reflection coefficient (RC) adjustment while satisfying the constraints on the total time, the transmit energy consumption, the circuit energy consumption and the achievable throughput for each BD by taking the causality and the non-linearity of energy harvesting into account. To deal with this intractable non-convex problem, we reformulate the problem by utilizing the Dinkelbach's method. Subsequently, an alternative iterative algorithm is designed to solve it. Simulation results show that the proposed algorithm achieves a much better EE than the benchmark algorithms.