发表机构
University College London; Southeast University（伦敦大学学院; 东南大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究针对 HARQ-CC 辅助的 sFAMA，提出 QoS 感知的并发度与 HARQ 极限联合设计，通过两阶段优化扩展了 FAS 的 QoS 可行区域，可支持更多并发用户。
AI 中文摘要
采用 Chase 合并的混合自动重传请求（HARQ-CC）可提升慢流体天线多址接入（sFAMA）的可靠性，但其传输极限需与用户并发度进行联合优化。本文针对下行链路 HARQ-CC 辅助的 sFAMA，提出一种感知服务质量（QoS）的并发度水平 U 与 HARQ 极限 C 的联合设计方案。基于选端口信干噪比（SIR）分布，推导多轮解码失败概率，并开发两阶段优化方法：先最大化可行并发度，再选择满足中断和平均服务约束的最小 C。证明对于给定 U，首个可行 C 可最小化服务时长，且可行 U 值构成初始区间，支持最优二分搜索。数值结果在全 Jakes 空间协方差下与蒙特卡洛仿真一致。所提自适应 FAS 设计支持 6 个并发用户，而固定 HARQ 的 FAS 为 3-5 个，HARQ 自适应固定位置天线（FPA）为 2 个，表明并发度与 HARQ 联合自适应可扩展 FAS 的 QoS 可行区域。
英文摘要
Hybrid automatic repeat request with Chase combining (HARQ-CC) improves the reliability of slow fluid antenna multiple access (sFAMA), but its transmission limit must be jointly optimized with user concurrency. This paper proposes a quality-of-service (QoS)-aware joint design of concurrency level U and HARQ limit C for downlink HARQ-CC-aided sFAMA. Based on the selected-port signal-to-interference ratio (SIR) distribution, we derive multi-round decoding failure probabilities and develop a two-stage optimization that maximizes feasible concurrency and then selects the minimum C satisfying outage and mean-service constraints. We prove that the first feasible C minimizes service duration for a given U, and that feasible U values form an initial segment, enabling optimal bisection search. Numerical results agree with Monte Carlo simulations under full Jakes spatial covariance. The proposed adaptive FAS design supports six concurrent users, compared with three to five for fixed-HARQ FAS and two for HARQ-adaptive fixed-position-antenna (FPA), demonstrating that joint concurrency and HARQ adaptation expands the QoS-feasible region of FAS.
