Research On Spectrum Sensing And Allocation In Wireless Sensor Network Aided Cognitive Radio

Wireless sensor network aided cognitive radio spectrum sensing, an innovative and promisingtechnique, consists of a wireless sensor network able to assist the cognitive network by providinginformation on the current spectrum occupancy, which will support the coexistence of licensed andunlicensed wireless users in a same area. This dissertation mainly researches on the spectrumsensing method and its improved algorithm in wireless sensor network aided cognitive radio, andthen on the basis of the results obtained spectrum sensing, combines quantum bacterial foragingoptimization algorithm to achieve fair and effective mechanism for spectrum allocation. The mainresearch works of this dissertation can be summarized as follows:Firstly, this paper describes the basic principle of spectrum sensing in wireless sensor networkaided cognitive radio as well as the system structure, then analyzes the local sensing algorithm andcooperative sensing algorithm for wireless sensor networks, focusing on the energy detection basedlocal spectrum sensing algorithm and three kinds of fusion mechanism of cooperative sensing. Thedetection performances of three different fusion mechanisms are compared by the experimentalsimulation under three channel conditions.Secondly, taking into account the constrained energy of sensor nodes, an improved spectrumsensing scheme for wireless sensor networks is proposed. The novelty of the proposed work is toaddress the selection of the best sensing nodes while minimizes the energy consumption tosimultaneously guarantee to meet the detection accuracy constraint. Simulation results show thatsignificant energy savings and considerable detection performance improvements are achieved bythe proposed schemes in three different channel scenarios.Thirdly, according to the results of spectrum sensing for wireless sensor networks, graph theorycoloring based spectrum allocation model is researched, then quantum bacterial foragingoptimization algorithm based cognitive radaio spectrum allocation scheme is put forward.Simulation results show that the proposed algorithm compared to the traditional spectrum allocationalgorithm can better realize the maximization of system efficiency and fairness.