Cooperative waiting-time reduction for cognitive radio networks using Stackelberg game

Waiting time occupies an important position in user´s quality-of-service (QoS) evaluation system. However, in conventional overlay cognitive radio networks (CRN), the secondary users are not permitted to transmit any personal information whenever the spectrum is occupied by primary users. It follows that the waiting time of users depends heavily on the primary spectrum occupancy, which, in turn, cannot guarantee the QoS of the secondary users. To remedy this, a game theoretical cooperative waiting-time reducing method (CWTRM) is proposed in a self-generated CRN to meet users´ waiting-time demands. The proposed scheme divides the users to temporary primary and secondary groups instead of introducing an extraneous secondary network. Specifically, waiting users are served as temporary secondary users. The cooperation between them and the temporary primary users is proceeded in each frame to make reuse of the unused time fractions, thereby reducing the global waiting time of the network. The optimal relay power, pricing and corresponding cooperating strategies are determined with the utilisation of Stackelberg game and Hungarian method. Finally, the superiority of the proposed CWTRM over non-cooperative schemes is validated through simulations.