Reconfigurable Intelligent Surface Assisted Anti-Jamming Communications: A Stackelberg Game Approach

In this paper, we consider a reconfigurable intelligent surface (RIS)-assisted anti-jamming network, where the RIS is utilized to enhance the legitimate transmission and mitigate the jamming interference by regulating reflected signals. To counteract malicious attacks from a smart jammer capable of adjusting its transmission power, we model the interaction between the transmitter and the jammer as a Stackelberg game, referred to as the Stackelberg game for RIS-assisted anti-jamming communications (SG-RIS-AJC). Specifically, the transmitter acts as the leader, aiming to maximize its utility with the RIS assistance, while the jammer acts as the follower, attempting to disrupt the legitimate transmission at minimal cost. In this game, we prove the existence and uniqueness of the Stackelberg equilibrium (SE) and derive the closed-form expressions for the power control strategies of both players. Furthermore, we obtain the near-optimal solutions for RIS phase shifts corresponding to each transmission strategy of the transmitter by employing the Majorization-Minimization (MM) algorithm and manifold optimization. Simulation results demonstrate that the proposed SG-RIS-AJC scheme effectively enhances the secure transmission performance compared to the non-RIS-assisted game-theoretic scheme and the RIS-assisted non-game-theoretic scheme in the presence of a smart jammer.