Research On Technologies Of Dynamic Spectrum Sensing Based On Cognitive Radio In Wireless Sensor Networks

Wireless Sensor Network is a wireless communication network technology which developingvery rapidly and used widely. Because its large amount of wireless nodes need to transmit and senseoutside information,it must have wireless spectrum resources that can be used at any time. With thedevelopment of wireless communication, a second question is scarce spectrum resources, whichbrings obstacle to the wide application of WSN. This article introduces Cognitive Radio into WSNand study dynamic spectrum sensing technology in the scenario in order to detect the idle spectrumfrom authorized spectrum.So it alleviates the problem of scarce spectrum resources.And at the sametime it improves the spectrum efficiency and throughput of WSN.In this thesis, we study dynamic spectrum sensing technologies based on cognitive radio inWSN.We should ensure that cognitive users can’t affect the authorized users,then they can use theidle spectrum resources. The article analyzes the deficiency of traditional wireless sensor network,and puts forward a CR-WSN network model and the spectrum sensing model.We verify theperformance of spectrum sensing in AWGN channel and Rayleigh fading channel throughMATLAB simulation platform.Then, we put forward a optimized spectrum sensing method basedon prediction mechanism in clustering structure WSN which adopts LEACH protocol.We gives anew selection principle for cluster head.The new method is a optimization measures under thepremise of last results.WSN is a data-centric network system, so single channel spectrum sensing can’t meet therequirements of the large amount of data transmission. The thesis discusses the multi-channelspectrum sensing technology, in which the packet loss rate and the system throughput are analyzed.The simulation results show that multi-channel spectrum sensing technology can not only reducethe packet loss rate of sink node but also improve the system throughput greatly.Finally, this thesis puts forward a multi-channel opportunity routing protocol based onmulti-channel spectrum sensing technology and combining with multi-channel MAC mechanism.Inthis route protocol, we put forward a kind of competition node routing selection method based onweights.The simulation results show that the proposed MORP protocol improves networkthroughput of the sink nodes in WSN and reduce the delay of the sink node receiving packets.