A contract-based cooperative spectrum sharing model in cognitive radio network

A contract-based cooperative spectrum sharing model in cognitive radio network was proposed. In this model, secondary user offers relay service for primary user when primary user 's channel is poor. In return, when primary user's channel is good, secondary user can use spectrum with the underlay mode under the condition that the interference is limited. Contract theory in economics was introduced to this framework, the problem of collaboration between the primary and secondary users was modeled as a contract design problem, and the effectiveness function of evaluate primary and secondary users on contract revenue was set up. And the differential evolution algorithm was used to solve the problem. Finally, in different circumstances, primary user collaboration and un-collaboration were contrasted. The results showed that the main users under the condition of no additional input spectrum, not only save the sending power, but also effectively improve the data transfer rate, and improve the energy efficiency and s