Resource Allocation for Low-Latency Communications in Slow Fluid Antenna Multiple Access Systems

The fluid antenna system (FAS) enhances wireless communication through dynamic adaptation to channel conditions. However, most existing studies focus on physical-layer metrics without considering link-layer low-latency quality-of-service (QoS) guarantees. This paper develops a cross-layer model to analyze the QoS performance in a slow fluid antenna multiple access (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$s$</tex>-FAMA) system using the effective capacity (EC) framework. We formulate and solve a joint port selection and power allocation problem to maximize total EC under total power and each user's minimum EC constraint. Simulation results demonstrate that our proposed algorithm significantly outperforms conventional uniform power allocation, highlighting the effectiveness of FAS in ensuring QoS.