Improved Utility-Based Cooperative Cognitive Radio Networks

As the demand on frequency spectrum continues to grow rapidly,the dynamic spectrum access by cognitive radio technologies becomes a hot research problem and a promising approach to increase the efficiency of spectrum utilization.In previous research, there is no inter-cooperation between primary and secondary users. So we wonder if we introduce a cooperative pattern, the performance of the whole network may be improved. In this paper,we suggest a new kind of cooperative pattern which on one hand,leveraging secondary users as the cooperative relays for the primary users transmission;similarly on the other hand, primary user can serve as secondary users relay, which can improve the whole rate of transmission.It has been showed in our work that to select a subset of the secondary users as relays properly, primary users data can be transferred in a shorter interval of time, which correspondingly lead to more spare time for secondary users data transferring, and also primary user may get more pay from the secondary users. Therefore,it is a win-win situation.Secondary users cooperating with primary transmissions have the right to decide their payment made for primary user in order to achieve a proportional access time to the wireless media and decide the strategy to transmit its data by cooperative transmission with primary user.Based on the system model, we analysis the network by Stackelberg game theory and find the unique Nash Equilibrium point.Then,we show that the framework we suggest is a improved one by our analytical results and simulation results.