Study On Resources Sharing In Cognitive Radio Networks Based On Game Theory

With the rapid development of wireless communication technology, the number ofwireless users and services gradually increases, and the limited spectrum resourcesbecome increasingly scarce. As a novel technology, the cognitive radio technologyimproves the efficiency of spectrum utilization by optimal resources allocation. However,cognitive radio spectrum sharing technology is an important guarantee in achieving theoptimal allocation of spectrum resources. In cooperative cognitive radio networks, as onekind of spectrum sharing, spectrum leasing models the game relationship between theauthorized users and cognitive users, and makes the game theory become a very effectivemathematical tool.First, this thesis proposes a power allocation mechanism for CDMA-based cognitiveradio networks. It enables cognitive users underlay access the spectrum resources whenthe authorized user is active. In order to guarantee the authorized user’s quality of service,the thesis sets the price for transmission power to constrain the power of the cognitiveusers. Simulation results show that the proposed menchanism significantly improves theutilities of both the authorized user and the cognitive users.Then, in order to eliminate the interference caused by the underlay spectrum sharing,a novel pricing model for spectrum leasing is proposed for cognitive radio networks. Thepricing model can be considered as a mechanism that enables the exchange between thespectrum access and the forward power. Due to the game relationship between theauthorized users and the cognitive users in cooperative cognitive radio networks, the novelspectrum leasing mechanism is formulated as a Stackelberg game. Moreover, the relayselection and admission control are also considered, aiming to achieve the fair allocationof the spectrum resources.To further ensure the fairness of network resources allocation, the authorized user’sutility and cognitive users’ utility need to be considered jointly, therefore, the Nashbargaining solution is used to formulate a cooperative game between the authorized userand the cognitive users. In addition, a non-cooperative game is formulated by taking into account the non-cooperative relationship among the cognitive users. By solving these twogames, the thesis gives the optimal slot allocation and optimal payment for the authorizeduser and the cognitive users, respectively. Simulation results show that the the spectrumleasing mechanism based on Nash bargaining makes a fairer and more reasonbleallocation of the spectrum resources, and significantly improves the performance of boththe authorized user and the cognitive users.