Wireless communication systems are increasingly vulnerable to sophisticated jamming attacks with the rapid evolution of jamming technologies and advanced signal processing techniques. While traditional anti-jamming techniques offer limited performance gains, active reconfigurable intelligent surfaces (RISs) have emerged as a promising channel-domain solution for improving resilience against jamming. Nonetheless, existing studies often rely on simplified electromagnetic (EM) models that do not fully capture mutual coupling (MC) and impedance mismatches in RIS hardware. In this paper, we propose an EM-compliant active (EMC-Active) RIS model for anti-jamming systems, explicitly incorporating the EM and physical properties at active RIS, such as MC effects, channel correlation, and discrete phase. To evaluate the anti-jamming performance of the proposed EMC-Active RIS, we develop a low-complexity alternating optimization (AO) algorithm based on the decoupling architecture (DA) to maximize the ergodic achievable rate. By leveraging the DA to explicitly eliminate MC effects among REs, the original coupled system is transformed into a tractable and scalable uncoupled representation. Numerical results demonstrate that the DA-based AO algorithm can significantly reduce the modeling and optimization complexity and efficiently solve the problem in an alternating manner with substantially reduced iteration overhead.

翻译：无线通信系统正面临日益复杂的干扰攻击挑战，随着干扰技术与先进信号处理技术的快速演进，传统抗干扰方法性能提升空间有限。有源可重构智能表面作为提升抗干扰鲁棒性的新兴信道域解决方案展现出潜力。然而现有研究普遍采用简化电磁模型，未能完整表征有源RIS硬件中的互耦效应与阻抗失配特性。本文提出一种面向抗干扰系统的电磁兼容有源RIS模型，明确纳入有源RIS的电磁与物理特性，包括互耦效应、信道相关性与离散相位。为评估所提EMC-Active RIS的抗干扰性能，我们开发了基于解耦架构的低复杂度交替优化算法，通过最大化遍历可达速率实现性能优化。利用解耦架构显式消除RIS单元间的互耦效应后，原始耦合系统被转化为易于处理的可扩展非耦合表示。数值结果表明，基于解耦架构的交替优化算法可显著降低建模与优化复杂度，在迭代开销大幅降低的同时高效实现交替求解。