Malicious jamming presents a pervasive threat to the secure communications, where the challenge becomes increasingly severe due to the growing capability of the jammer allowing the adaptation to legitimate transmissions. This paper investigates the jamming mitigation by leveraging an active reconfigurable intelligent surface (ARIS), where the channel uncertainties are particularly addressed for robust anti-jamming design. Towards this issue, we adopt the Stackelberg game formulation to model the strategic interaction between the legitimate side and the adversary, acting as the leader and follower, respectively. We prove the existence of the game equilibrium and adopt the backward induction method for equilibrium analysis. We first derive the optimal jamming policy as the follower's best response, which is then incorporated into the legitimate-side optimization for robust anti-jamming design. We address the uncertainty issue and reformulate the legitimate-side problem by exploiting the error bounds to combat the worst-case jamming attacks. The problem is decomposed within a block successive upper bound minimization (BSUM) framework to tackle the power allocation, transceiving beamforming, and active reflection, respectively, which are iterated towards the robust jamming mitigation scheme. Simulation results are provided to demonstrate the effectiveness of the proposed scheme in protecting the legitimate transmissions under uncertainties, and the superior performance in terms of jamming mitigation as compared with the baselines.

翻译：恶意干扰对安全通信构成普遍威胁，且随着干扰器适应合法传输的能力日益增强，这一挑战变得愈发严峻。本文研究利用主动可重构智能表面（ARIS）进行干扰抑制，并特别针对信道不确定性进行鲁棒抗干扰设计。针对该问题，我们采用Stackelberg博弈框架来建模合法方与对手之间的策略交互，二者分别作为领导者和跟随者。我们证明了博弈均衡的存在性，并采用逆向归纳法进行均衡分析。首先，我们推导了作为跟随者最优响应的最优干扰策略，随后将其纳入合法方的优化问题中以实现鲁棒抗干扰设计。我们处理了不确定性问题，并通过利用误差界来对抗最坏情况下的干扰攻击，从而重构了合法方的优化问题。该问题在块连续上界最小化（BSUM）框架内被分解，分别处理功率分配、收发波束成形以及主动反射，通过迭代最终得到鲁棒的干扰抑制方案。仿真结果验证了所提方案在不确定性下保护合法传输的有效性，以及在干扰抑制性能上相较于基线方法的优越性。