Cooperative Spectrum Sharing in Cognitive Radio Networks: A Centralized Contracted-Based Approach

In this paper, we study the relay-based communication schemes for cooperative spectrum sharing among multiple primary users (PUs) and multiple secondary users (SUs) with incomplete information. Inspired by contract theory, we model the network as a labor market. In this market, PUs and SUs are regarded as employer and employee respectively. Each PU proposes certain contracts to attract the SUs, the contract include relay power and spectrum access time, each SU maximize its utility by selecting the most suitable contract. But PUs and SUs have conflicting objectives in contract content. To tackle this problem, we put forward to a centralized maximizing expectation utility scheme, which convert the optimal contract design into an optimization problem. After that, a approximate method for solving the optimization problem is proposed. Simulation results show that the losses of PUs’ total utilities caused by incomplete information and approximate algorithm are relatively small, especially when the number of SUs is very large.