Energy-Recycling Full-Duplex Radios for Next-Generation Networks

TL;DR

This paper introduces an energy-recycling full-duplex radio architecture that enhances spectral efficiency and reduces energy consumption by recycling leaked energy and improving self-interference cancellation, with significant performance gains demonstrated.

Contribution

A novel energy-recycling full-duplex radio design with a 3-port element that improves spectral efficiency and energy efficiency over existing solutions.

Findings

Achieves up to 40% rate gains over state-of-the-art methods.

Recycles up to 50% of leaked circulator energy, equivalent to 5% of transmitted energy.

Validated analytical models with numerical simulations.

Abstract

In this work, a novel energy-recycling single-antenna full-duplex (FD) radio is designed, in which a new 3-port element including a power divider and an energy harvester is added between the circulator and the receiver (RX) chain. The presence of this new element brings advantages over the state of the art in terms of both spectral efficiency and energy consumption. In particular, it provides the means of performing both an arbitrary attenuation of the incoming signal, which in turn increases the effectiveness of the state-of-the-art self-interference cancellation strategies subsequently adopted in the RX chain, and the recycling of a non-negligible portion of the energy leaked through the non-ideal circulator. The performance of this architecture is analyzed in a practically relevant 4-node scenario in which 2 nodes operate in FD and 2 nodes in half-duplex (HD). Analytical approximations are derived for both the achievable rates of the transmissions performed by the FD and HD radios and the energy recycled by the FD radios. The accuracy of these derivations is confirmed by numerical simulations. Quantitatively, achievable rate gains up to 40% over the state-of-the-art alternatives, in the considered scenario, are highlighted. Furthermore, up to 50% of the leaked energy at the circulator, i.e., 5% of the energy of the transmitted signal, can be recycled.