Research On Spectrum Sensing Technology In Cognitive Radio Vehicle Ad Hoc Networks

In recent years,with the rapid development of the automotive industry and wireless communication technology,people’s demand for safer and more efficient traffic environment has become more and more urgent.Intelligent Transportation Systems have gained widespread attention.As one of the key technologies of intelligent transportation systems,Vehicular Ad Hoc Network has also received increasing attention from researchers.Due to the fixed spectrum allocation policy and the low spectrum utilization for which has been allocated,the lack of spectrum has become a limiting factor for the development of Vehicle Ad Hoc Networks.At present,Cognitive Radio technology is considered to be the most effective way to solve spectrum shortage and improve spectrum utilization.Applying cognitive wireless technology to the vehicle environment forms the Cognitive Radio Vehicle Ad Hoc Network,which has become an effective way to solve the shortage of spectrum problem of the vehicle network.First,this paper analyzes the relevant background of the research and introduces the basic concepts and key technologies of cognitive radio technology and Vehicle Ad Hoc Network in detail.Then,three spectrum sensing technologies are introduced and are compared and analyzed from the system architecture,technical characteristics and scope of use.Particularly,the energy detection method is introduced in detail from the theoretical analysis of the realization principle and influencing factors.And do simulation to verify the relevant theory.Then,the deficiencies of single-node spectrum sensing are analyzed,and the necessity of cooperative spectrum sensing technology is pointed out.For the scenario of the vehicle network,the application scenario model of cooperative spectrum sensing is established,and the network architecture,technical characteristics and fusion criteria of the cooperative spectrum sensing technology are analyzed in detail.On this basis,the spectrum sensing performance under the common hard decision fusion criterion is simulated,and the performance of the cooperative spectrum sensing algorithm in the composite fading channel is simulated.The simulation results show that the cooperative spectrum sensing algorithm outperforms the single-node spectrum sensing algorithm under the same channel conditions.Then,for the security problem in cooperative spectrum sensing,a reliable spectrum sensing algorithm based on trust is adopted.By giving cognitive nodes a trustworthiness value that characterizes their reliability,the goal of combating malicious nodes and improving system perceived reliability is achieved.By simulating the detection performance under three hard decision fusion criteria,the cooperative spectrum sensing algorithm based on trust can effectively improve the detection performance of the system.Finally,based on NS-3 network simulation software,the LTE-V2 X simulation platform is built,and the cognitive vehicle network environment is constructed.The system-level simulation is carried out for the cooperative spectrum sensing algorithm based on trust.The simulation results show that the UE can implement V2 X communication by dynamic access of spectrum holes by using the spectrum-aware algorithm based on trust degree.Spectrum-aware algorithm based on trust degree can effectively improve the throughput of the network,compared with cooperative spectrum sensing algorithm.