Cooperative Spectrum Sharing Strategy In Cognitive Radio Networks Based On Spectrum Contract

With the rapid development of social information industry, the demand for radio spectrum resources is increasing. Compared to the rapid development of communications technology,the lack of spectrum resources has become a key factor restricting the rapid development of wireless communication. To solve the above problems, dynamic spectrum management mechanisms in cognitive radio technology allows unauthorized user to use licensed frequency band, and thus to increase the spectrum utilization of authorized band. Cooperative spectrum sharing technology as a key technology in cognitive wireless network allows the cooperation between the primary user and the secondary user and primary user and the secondary user can share resources through a variety of dynamic spectrum access methods. Compared with cooperative spectrum sharing based currency transactions, cooperative spectrum sharing based resource deal does not depend on elusive currency trading system, and make primary user get more spectrum resources. Therefore, cooperative spectrum sharing based on resources has become a hot topic. In order to solve the problem of cooperative spectrum sharing based on resources between primary users and secondary users, in this paper the problem is modeled as labor market, use the contract theory to build effective contract for this problem and has the following research:1. To solve the problem of contract-based cooperative spectrum sharing between multiple primary users and multiple secondary users, a contract design method is put forward and aim to make the multiple primary users obtain the maximal total utility, which is based on statistical. Simulation results and analysis show the contract design method solve the problem of contract-based cooperative spectrum sharing successfully and compared with the DMA-UI, the approach we approved can make primary users obtain a higher utility, in turn improve the primary users’ power efficiency and spectrum efficiency.2. A contract-based cooperative spectrum sharing model in cognitive radionetworks is proposed, which improves energy efficiency and spectral efficiency significantly. Then we establish optimization problem how to design the optimal contract to make primary user get the maximal benefit, the differential evolution algorithm is used to solve the optimization problem. The numerical results show that through the establishment of the model, not only save primary user’s transmitting power, but also improve the date rate, thereby the power and spectrum efficiency have been improved.