Research On The Spectrum Utilization Rate Of Cognitive Radio And Collaborative Communication

The spectrum is getting more and more intense,in order to improve the low frequency of spectrum utilization,the proposed cognitive radio(CR)adds the use opportunity of spectrum for cognitive users by sharing spectrum resources.There are four main research directions in cognitive radio technology,include spectrum perception,spectrum allocation,spectrum sharing and spectrum switching.This paper focuses on the spectrum allocation algorithm to improve the spectrum utilization.Secondly,in cognitive radio communication,signal transmission is affected by multi-path fading effect.Therefore,collaborative communication is introduced in cognitive radio to improve communication quality and reliability.This paper mainly studies the selection of relay node location between cognitive users,by seeking the better relay node to improve quality of service(QoS)in communication.Firstly,this paper briefly introduces the background and significance of research,the development status and the work arrangement.Elaborated the basic theory of CR,include its composition and structure,classification of spectrum allocation,the principle of design spectrum allocation algorithm,and show spectrum allocation model.In addition,introduce three main research directions in the combination of collaborative communication technology with CR: spectrum sensing,collaborative communication between authorized users and cognitive users,then briefly describes the concept of collaborative communication and its technology.Secondly,based on the traditional Glowworm Swarm Optimization(GSO)algorithm,this paper proposes an Improved Glowworm Swarm Optimization(IGSO)algorithm,which converts fixed step into adaptive automatically step to effectively improve computational accuracy and convergence speed by adaptive factor.And combines with chaotic search strategy to optimize the individual and enhance global search property.Through the spectrum allocation model and four standard function experiment simulation results show that IGSO algorithm is further improve the accuracy,stability of convergence and the Max sum reward than GSO algorithm.Lastly,in order to improve QoS of cognitive radio network(CRN),this paper applies collaborative communication to cognitive users,and further studies the selection of location-based relay nodes.Through analysis of the relationship between the channel capacity and the relay node location,this paper proposes a Mobile-Cooperative Relay Scheme(MCRS),then analyzes the principle of two network environments from single-cognitive users and multi-cognitive users,and simplifies the communication between multi-cognitive users based on the sacrifice of certain efficiency.Thesimulation results show that the proposed scheme is better than the original relay scheme and the direct transmission scheme,which is the best in the Signal to Interference plus Noise Ratio(SINR).