Performance analysis of cooperative spectrum sensing in Cognitive Radio using game theory

Cognitive Radio (CR) aims to provide efficient utilization of the scarcely available radio spectrum. Spectrum sensing is indispensable to identify spectrum holes. Inaccurate sensing results in interference to PU. Therefore, sensing accuracy is an important parameter. Cooperative Spectrum Sensing (CSS) is an efficient technique to improve the sensing accuracy. It makes use of cooperation between Secondary Users (SUs) to detect the presence of Primary User (PU). Game theoretical models help in understanding and modeling interaction among users. In this paper, a CR network with multiple PUs and SUs is considered. CSS is modeled as hedonic coalition formation game where SUs sensing the same channel form coalitions. The coalitions are formed on the basis of probability of detection. For each PU, the SUs which have maximum probability of detection form coalition and cooperatively make the final sensing decision by making use of OR rule. Channel estimation for ST-SR link is done using WARP testbed. The sensing accuracy and energy consumption for the coalitions when link is modeled using free space pathloss model and using WARP testbed are found out. Simulation results show that CSS modeled using hedonic coalition formation has better sensing accuracy than non-cooperative sensing.