Efficient Battery Usage in Wireless-Powered Cell-Free Systems with Self-Energy Recycling

TL;DR

This paper proposes a novel method for wireless-powered cell-free systems that enhances energy efficiency through self-energy recycling, optimizing battery usage while maintaining data rate requirements.

Contribution

It introduces a closed-form energy harvesting bound, formulates a non-convex optimization problem, and develops a convergent alternating optimization algorithm for improved energy efficiency.

Findings

The proposed method reduces battery energy consumption compared to existing algorithms.

It achieves lower outage rates in wireless-powered cell-free systems.

Numerical results validate the effectiveness of the proposed approach.

Abstract

This paper investigates wireless-powered cell-free systems, in which the users send their uplink data signal while simultaneously harvesting energy from network nodes and user terminals - including the transmitting user terminal itself - by performing self-energy recycling. In this rather general setting, a closed-form lower bound of the amount of harvested energy and the achieved signal-to-interference-plus-noise ratio expressions are derived. Then, to improve the energy efficiency, we formulate the problem of minimizing the users' battery energy usage while satisfying minimum data rate requirements. Due to the non-convexity of the problem, a novel alternating optimization algorithm is proposed, and its proof of convergence is provided. Finally, numerical results show that the proposed method is more efficient than a state-of-art algorithm in terms of battery energy usage and outage rate.