Performance Analysis of Slow Fluid Antenna Multiple Access in Noisy Channels Using Gauss-Laguerre and Gauss-Hermite Quadratures

Abstract

Fluid antenna system (FAS) facilitating a position-switchable antenna, enables a mobile receiver to exploit the deep fade opportunity of its interference for multiple access. Slow fluid antenna multiple access ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$s$ </tex-math></inline-formula> -FAMA) is such an emerging proposal that lets multiple users share the same time-frequency channel while each user adopts a fluid antenna to resolve the interference. Previous performance analysis is limited to the case when noise is neglected. In this letter, we remove this limitation and derive new closed-form expressions for the outage probability of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$s$ </tex-math></inline-formula> -FAMA by using Gauss-Laguerre and Gauss-Hermite Quadratures. The analysis reveals the impact of noise on the outage probability for different numbers of users and ports in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$s$ </tex-math></inline-formula> -FAMA networks.