A coalitional game model for cooperative cognitive radio networks

Abstract

In this paper we exploit a setting for cognitive radio networks by utilizing cooperation from secondary users (SUs) to assist the transmissions of operators' primary users (PUs). On the other hand, SUs can share the spare spectrum of operators. Such a scenario can be viewed as a market where multiple operators trade their spare spectrum for the assistance of SUs, and multiple SUs trade the transmission energy for access opportunities from operators. We model the system using transferable payoff coalitional game theory. An outcome of a coalitional game is a specification of the coalition that forms and the joint action it takes. We show that the optimum joint action strategy can be obtained as a solution of convex optimization problem. Then, based on dual technique, we show that there is an operating point that maximizes the sum utility over the operators and SUs while providing each player a share such that no subset of operators and SUs has an incentive to break away from the brand coalition.