Mitigating Self-Interference Among IEEE 802.22 Networks: A Game Theoretic Perspective

In this paper, we use game theory to mitigate self-interference among cognitive radio based IEEE 802.22 networks such that these networks can efficiently co-exist. When a network experiences interference, it can adopt either one of two choices-switch to a new band hoping to find a non-interfering one, or stay with its current band hoping that the interfering network(s) will move away to a new band. We model the spectrum band switching process as an infinite horizon repeated game where the aim of each network (player) is to find a channel void of interference from it´s neighboring networks incurring minimal cost. We investigate both pure and mixed strategy solution space of the game and show that pure strategy solution of the game is infeasible. Thus a mixed strategy is proposed which achieves subgame-perfect Nash Equilibrium. Simulation results reveal that using the proposed strategies, each network can find a clear channel quickly and at the same time incur a low cost.