Is Self-Interference in Full-Duplex Communications a Foe or a Friend?

TL;DR

This paper explores energy harvesting from self-interference in full-duplex base stations, proposing an optimization framework that enhances energy efficiency through joint beamforming, power allocation, and time-splitting strategies.

Contribution

It introduces a novel energy-efficiency maximization model for full-duplex systems that leverages self-interference for energy harvesting, with an iterative solution approach.

Findings

Significant energy-efficiency improvements via self-energy recycling.

Effective joint design of beamformers, power, and time-splitting.

Successful application of successive convex approximation for nonconvex optimization.

Abstract

This paper studies the potential of harvesting energy from the self-interference of a full-duplex base station. The base station is equipped with a self-interference cancellation switch, which is turned-off for a fraction of the transmission period for harvesting the energy from the self-interference that arises due to the downlink transmission. For the remaining transmission period, the switch is on such that the uplink transmission takes place simultaneously with the downlink transmission. A novel energy-efficiency maximization problem is formulated for the joint design of downlink beamformers, uplink power allocations and transmission time-splitting factor. The optimization problem is nonconvex, and hence, a rapidly converging iterative algorithm is proposed by employing the successive convex approximation approach. Numerical simulation results show significant improvement in the energy-efficiency by allowing self-energy recycling.