Realization of spectrum sharing and performances analysis in cognitive radio networks

In cognitive radio networks, the spectrum of primary users is not fully utilized. In order to improve the spectrum utilization efficiency, secondary users can share the spectrum with primary users, where the primary users can get revenue due to quality of service performance (QoS) degradation and secondary users can meet their demand of the spectrum. In this paper, we establish a system model composed of multiple primary and secondary controllers in cognitive radio networks. Each controller operates at multiple frequency points and connects multiple users. The primary controllers connecting local users are spectrum sellers and buyers are secondary controllers serving secondary users. We obtain the equilibrium for spectrum trading through the demand and the supply function. Two cases are considered where controllers are aware of others. Case I is multiple equilibriums are obtained at the same time and in case II controllers not in equilibrium states for some frequency can get the pricing information of others which have realized spectrum trading. The two cases are investigated and performances are analyzed.