Research On Spectrum Sensing Technology And Energy Saving Algorithm In Cognitive Wireless Sensor Networks

Cognitive Wireless Sensor Network(CWSN)is a new type of intelligent network that combines traditional wireless sensor netw ork(WSN)and cognitive radio(CR)technology.The cognitive wireless sensor network can use the spectrum sensing technology to discover the spectrum holes in the licensed frequency band and communicate with the opportunistic access.Therefore,the network can simultaneously communicate in the ISM frequency band and the licensed frequency band,and can timely send the environmental inf ormation collected by the nodes,and solve the problem of tight spectrum resources.At the same time,considering that the nodes of cognitive wireless sensor networks are not powerful and have limited energy,it is necessary to design a relatively energy-efficient and efficient spectrum sensing algorithm.This paper proposes an improved spectrum sensing scheme based on cognitive wireless sensor networks.Firstly,on the energy detection model,variable weights based on signal-to-noise ratio are introduced for weight detection,and the decision statistics are optimized.Each node optimizes the weight according to the real-time signal-to-noise ratio,which can weaken the influences of nodes in the unfavorable position.Simulations show that network detection performance can be improved.Secondly,based on the above improvements,this paper introduces a double threshold spectrum sensing technology,and performs the second decision on the statistics falling in the fuzzy area.Through the simulation results,the comprehensive improved spectrum sensing algorithm can effectively improve the detection probability of the network and reduce the false alarm probability.Thirdly,considering of the limited energy of CWSN,an energy-efficient routing optimization scheme in clustered cognitive wireless sensor networks is proposed.Based on the existing clustering routing protocol,the scheme optimizes the cluster heads election mechanism,by considering the influences of the remaining energy and relative position of the node s.In the clustering stage,the node prioritizes the communication with the base station,then consider adding it to the general cluster.At the same time,the spectrum sensing function of the node introduces a sleep mechanism.Under the condition of satisfying the target detection probability and the false alarm probability,the number of nodes participating in the spectrum sensing function is optimized,and the energy consumption is reduced.The experimental simulation shows that the integrated improved algorithm consumes less energy and is more balanced,and the life of the network is extended.