Collaborative Detection Algorithm And Game Of Cognitive Radio Spectrum Allocation Policy

Cognitive radio networks provide high bandwidth to mobile users via dynamic spectrum access techniques, which has become a hot research issue in next-generation wireless network. Spectrum sensing and allocation are two key problems in cognitive radio network. Based on the analysis of key issues on spectrum sensing and allocation, new schemes are proposed to improve the spectrum efficiency. The main works are as follows:Firstly, to achieve sensing of licensed spectrum, a spectrum sensing algorithm based on secondary threshold cooperative nodes optimization (STCNO) is proposed. Double threshold nodes subarea criterion is established to divide cognitive nodes into trusted team and non-trusted team by the received signals energy. The correct sensing probability, signal-to-noise and distance between cognitive node and licensed node are used to construct a selection function, which is used to choose nodes from non-trusted team, then associates them with trusted team as cooperative sets for participating in cooperative sensing. The local sensing result, signal-to-noise and correct sensing probability are sent to the fusion center by cooperative nodes which are processed by fusion center using local information credit to obtain global sensing result, and then the detection probability in cognitive radio system is improved.Secondly, to achieve reasonable allocation of spectrum holes under interference constraint, an interference constraint of spectrum allocation based on potential game scheme (ICSAPG) is proposed. The spectrum allocation model based on potential game theory is founded, and the mutual interference aroused by cognitive radio users which use the same channel is considered to design interference function which restricts cognitive radio users to choose channels satisfied with interference constraint. At the same time utility function based on game theory is designed with the goal of maximizing throughput to guide cognitive radio users to choose optimal transmittable channel, and to obtain the maximize throughput of cognitive radio system with the precondition of satisfying total interference constraint.Finally, performance evaluations of the proposed STCNO and ICSAPG are taken under simulation. The sensing performance, traffic of control channel, interference grade, and throughput are analyzed, and the results show the reasonability of STCNO and ICSAPG on improving spectrum efficiency.