Game Theoretic Rate Adaptation for Spectrum-Overlay Cognitive Radio Networks

We consider the issue of fair share of the spectrum opportunity for the case of spectrum-overlay cognitive radio networks. Owing to the decentralized nature of the network, we adopt a pricing based game-theoretic approach where the actions of players would be choosing the modulation rate. The resulting game can be verified to be supermodular, and thus has at least one pure strategy Nash equilibrium. Next, we propose a Stochastic Approximation based algorithm for the computation of best response correspondence whose convergence to the Pareto-dominant Nash equilibrium can be established. Furthermore, we also propose a decentralized algorithm for tuning the price factor of the network. Our simulation results demonstrate the gains that can be achieved with pricing.