On the Level Crossing Rate of Fluid Antenna Systems

TL;DR

This paper analyzes the level crossing rate of fluid antenna systems, deriving analytical expressions and validating them through simulations, providing insights into system performance and parameter selection.

Contribution

It introduces a closed-form analytical framework for the LCR of fluid antenna systems and compares it with conventional systems, filling a gap in existing research.

Findings

Analytical expressions for LCR of FAS derived and validated.

LCR of FAS can match that of conventional systems under certain conditions.

Numerical results guide optimal parameter selection for improved performance.

Abstract

Multiple-input multiple-output (MIMO) technology has significantly impacted wireless communication, by providing extraordinary performance gains. However, a minimum inter-antenna space constraint in MIMO systems does not allow its integration in devices with limited space. In this context, the concept of fluid antenna systems (FASs) appears to be a potent solution, where there is no such restriction. In this paper, we investigate the average level crossing rate (LCR) of such FASs. Specifically, we derive closed-form analytical expressions of the LCR of such systems and extensive Monte-Carlo simulations validate the proposed analytical framework. Moreover, we also demonstrate that under certain conditions, the LCR obtained coincides with that of a conventional selection combining-based receiver. Finally, the numerical results also provide insights regarding the selection of appropriate parameters that enhance the system performance.