Design And Implementation Of Communication Platform For Internet Of Vehicles Based On Cognitive Radio

In recent years,traffic jam,traffic safety and the environment pollution in cities have been increasingly grave issues.Under this circumstance,the technology of Internet of Vehicles is attracting wide attention.But with the development of Internet of Vehicles,the applying scale expands incessantly so that the current spectrum resource cannot meet the communication demands.According to the research of the Federal Communications Commission,the traditional static spectrum assignment policy is a huge waste of spectrum resource.Cognitive radio technology can sense and opportunistic access the idle spectrum and make the unlicensed users share the spectrum with the licensed users without interference,which is a good solution to provide extra spectrum for the Internet of Vehicles.Nowadays,many research institutions has been study the application of cognitive radio in Internet of Vehicles.But the present research is only about theoretical and computer simulation,there is no practical platform for testing and verification.The thesis stems from a joint project of Beijing Municipal Commission of Education and central universities“Application and Development Technologies of Bus Internet".On the basis of the research of cognitive radio and Internet of Vehicles,we designed and built a communication platform for Internet of Vehicles based on cognitive radio using USRP and GNU radio.The main work is as follows:Firstly,the cognitive radio and Internet of Vehicles are briefly introduced including their concepts,key technologies and the current implementation schemes of platform.And the current researches of the application of cognitive radio in Internet of Vehicles are analyzed and summed up meanwhile.Based on the requirement analysis,then we designed and implemented the network structure and node architecture.The design and implementation of the node software architecture including the physical layer,the MAC layer,the application layer and the interface between layers is mainly described.The data transceiver module and spectrum detection module are designed and implemented in physical layer.The cooperative detection and converging module,the multi-channel operation module and the support module are designed and implemented in MAC layer.The vehicle terminal application and the demonstration and monitoring interface application are designed and implemented in application layer.The interface between layers are based on UDP socket technique.Finally,we test the function and performance of the platform in static and mobile environment and the scenario of with or without emergency users and cognitive radio to verify the design and implementation of the platform is effective.The results show that on one hand the communication platform for Internet of Vehicles based on cognitive radio can lower the influence on emergency users than the traditional platform based on WAVE,and on the other hand,it can improve the spectrum utilization without interfering the licensed users,when the arrival rate of licensed users is between 0 and 0.5,it can averagely improve the spectrum utilization about 114.1%.