Research On Channel Allocation Algorithm Of Sensor Network Based On Cognitive Radio

With the development of wireless and mobile communications,industry needs more spectrum resources to support a large number of emerging wireless services.However,in the current spectrum management framework,all spectrum are only assigned to specific services and are not available to unauthorized users.Spectrum scarcity is a concern for wireless system designers and telecom policymakers.The actual survey results show that the licensed spectrum is not fully utilized in the huge time and space dimensions.In order to solve the problem of spectrum scarcity and insufficient utilization,cognitive radio technology is proposed.It improves spectrum utilization by allowing unauthorized users to borrow idle spectrum of the authorized users or share it.As the core technology of cognitive radio,spectrum sensing and spectrum allocation need to accurately and quickly identify the idle spectrum and make reasonable allocation.In order to improve the transmission reliability and spectrum utilization in cognitive radio,this thesis makes an in-depth study on spectrum sensing and spectrum allocation,and proposes related algorithms.The specific research contents are as follows:1.To solve the problem of ignoring the relation between sensor distribution and shadow fading in traditional cooperative spectrum sensing,a maximum reliability cooperative spectrum sensing algorithm(MRSSA)is presented.MRSSA adds spatial correlation to the traditional detection probability and false alarm probability to ensure uniform sensor location distribution and reduce the redundancy of sensory information collection.A new cooperative sensing set construction scheme is proposed,and the calculation is simplified by introducing the central node.Then,the set is taken as the sample space,and under the limited energy characteristic of the wireless sensor network,the optimal set is periodically selected as the sensing set and the sample space is updated.Finally,the simulation results show MRSSA improves the reliability of spectrum sensing effectively.In the case of non-uniform sensor distribution,the anti-shadow fading interference capability is significantly improved.2.At present,the spectrum allocation scheme only focuses on continuous spectrum,which leads to low spectrum utilization.To solve the problem,spectrum aggregation technology was introduced,which aggregates multiple discrete spectrums into a larger bandwidth spectrum to meet the needs of different users.A multi-user upper confidence bound algorithm(MUCBA)based on spectrum aggregation is proposed.MUCBA uses the cooperative spectrum sensing algorithm of the research one to obtain the spectrum hole condition.The allocation is refined by sliding window mechanism and unit channel,and the one-to-one allocation rule is extended to many-to-many.Then the multiple multi-armed bandit model is established,and the traditional upper confidence bound algorithm is improved,so that multiple nodes exchange information and converge together.The simulation shows that MUCBA improves the reliability of data transmission and the spectrum utilization,especially in the case of discrete idle spectrum.