Combating Full-Duplex Duplex Active Eavesdropper: A Hierarchical Game Perspective
Abstract: Security is an issue of paramount importance, yet is it a significant challenge for wireless communications, which becomes more intricate when facing a full duplex (FD) active eavesdropper capable of performing eavesdropping and jamming simultaneously. In this paper, we investigate the physical layer security issue in the presence of an FD active eavesdropper, who launches jamming attacks to further improve the eavesdrop eavesdropping. ping. The jamming, however, also results in selfself interference at the eavesdropper itself. This security problem is formulated within a hierarchical game framework where the eavesdropper acts as the leader and the legitimate user is the follower. In particu particular, lar, we first investigate the follower's secrecy rate maximization problem and derive the optimal legitimate transmission strategy. Then, the leader's wiretap rate maximization is expressed as a mathematical program with equilibrium constraints (MPEC). Leveraging Lev the concavity of the follower's problem, we transform the MPEC problem into a single-level level optimization and obtain the jamming power allocation strategy by applying the primal-dual dual interior interior-point point method. Moreover, we analyze the situations where only ly partial channel state information is available at the legitimate user and the corresponding impacts on the game. Finally, we present extensive simulation results to validate our theoretical analysis.