AI 中文总结
本文针对FARIS辅助系统的安全通信问题，提出交替优化框架联合优化波束成形与FARIS配置，所提方案性能优于基准且鲁棒性好，可用于提升复杂环境下的安全通信能力。
AI 中文摘要
本文研究由流体有源可重构智能表面（FARIS）辅助的安全下行链路传输，FARIS可实现有源反射和动态端口选择，为物理层安全提供更高灵活性。我们构建保密速率最大化问题，在实际功率约束下联合优化发射波束成形器、有源反射系数和流体端口配置。为高效求解该高度非凸问题，我们开发定制的交替优化（AO）框架，将原联合设计分解为可处理的子问题，每个子问题既能高效求解又能保留系统约束，实现波束成形与FARIS重构的有效联合优化。数值结果表明，所提FARIS辅助设计始终优于基准方案，且进一步凸显FARIS对不利窃听几何结构的鲁棒性，确认其作为挑战性环境中安全通信强大使能器的潜力。
英文摘要
This paper investigates secure downlink transmission assisted by a fluid active reconfigurable intelligent surface (FARIS), which enables both active reflection and dynamic port selection, offering enhanced flexibility for physical-layer security. We formulate a secrecy rate maximization problem that jointly optimizes the transmit beamformer, active reflection coefficients, and fluid port configuration under practical power constraints. To efficiently handle the resulting highly nonconvex problem, we develop a tailored alternating optimization (AO) framework that decomposes the original joint design into tractable subproblems, where each admits an efficient solution while preserving the system constraints, enabling an effective joint optimization of beamforming and FARIS reconfiguration. Numerical results demonstrate that the proposed FARIS-assisted design consistently outperforms the benchmarks. The results further highlight the robustness of FARIS against unfavorable eavesdropping geometries, confirming its potential as a powerful enabler for secure communications in challenging environments.
