Fluid Antenna-aided Full Duplex Communications: A Macroscopic Point-Of-View

TL;DR

This paper develops an analytical framework using stochastic geometry to evaluate the performance of fluid antenna-assisted full-duplex cellular networks, considering channel estimation and residual interference, showing significant sum-rate improvements.

Contribution

It introduces a novel stochastic geometry-based analysis for FA-aided FD networks that accounts for imperfect channel estimation and residual interference, which was not addressed in prior work.

Findings

FA-aided FD networks achieve approximately 45% higher average sum-rate.

The framework accurately models the impact of channel estimation errors.

Residual loop-interference significantly affects network performance.

Abstract

The synergy of fluid-based reconfigurable antenna (FA) technology and full-duplex (FD) communications can be jointly beneficial, as FD can enhance the spectral efficiency of a point-to-point link, while the new degree of freedom offered by the FA technology can be exploited to handle the overall interference. Hence, in this paper, an analytical framework based on stochastic geometry is developed, aiming to assess both the outage and average sum-rate performance of large-scale FA-aided FD cellular networks. In contrast to existing studies, where perfect channel state information is assumed, the developed framework accurately captures the impact of channel estimation (CE) on the performance of the considered network deployments, as well as the existence of residual loop-interference (LI) at the FD transceivers. Particularly, we focus on a limited coherence interval scenario, where a novel sequential linear minimum-mean-squared-error-based CE method is performed for all FA ports and LI links, followed by data reception from the port with the strongest estimated channel. By using stochastic geometry tools, analytical expressions for the outage and the average sum-rate performance are derived. Our results reveal that FA-aided FD communications experience an improved average sum-rate performance of around 45\% compared to conventional FD communications.