Research On Integrated Business Bearing Scheme Of Urban Rail Transit Vehicle-ground Wireless Communication Based On TD-LTE

With the development of urban rail transit operation,the vehicle-to-ground wireless communication system needs to meet the requirements of large transmission bandwidth,low delay,high data volume,high mobility and standardization.The vehicle-ground wireless communication system mainly carries information such as passenger information system(PIS),video surveillance system(CCTV)and train control system(CBTC).The information of passenger information system(PIS)and video surveillance system(CCTV)is carried by the wireless subsystem of passenger information system,and the information of train control system(CBTC)is carried by the wireless subsystem of signal information.Both of them mainly use wireless local area network(WLAN)technology.Practice has proved that although WLAN technology can meet the requirements of vehicle-to-ground wireless communication,it has many limitations,such as short coverage distance,serious wireless interference,train speed limitation,multi-service concurrent can not be scheduled according to priority,and so on.Moreover,the two sets of vehicle-ground wireless systems cause duplication of equipment,especially the numerous equipment in the interval,which is not easy to install and maintain.With the rapid development of wireless transmission technology and the maturity and commercialization of 4G mobile communication technology based on TD-LTE,it has many technical advantages,such as high data rate,bidirectional,low delay,strong anti-interference,flexible deployment,downward compatibility and high mobility.In order to verify the feasibility of using TD-LTE for integrated wireless bearings of rail transit vehicles,this paper mainly studies the bandwidth of integrated bearings of TD-LTE.Distribution and networking,coverage scheme,and test and verify the scheme.Firstly,this paper compares the application status of wireless technology in rail transit vehicle-to-ground in China and abroad,and analyses the adaptability of TD-LTE in the application of wireless transmission in rail transit vehicle-to-ground.Secondly,the business and bandwidth requirements of wireless transmission between rail transit vehicles and ground are analyzed,and the technical scheme of TD-LTE vehicle-ground wireless integrated bearing is formulated.The experimental network is built in Zhengzhou rail transit real environment for testing,and the key and difficult problems in testing are analyzed.The feasibility of using TD-LTE in the integrated load-bearing of rail transit vehicle-ground wireless communication is verified by testing.According to the research conclusion,TD-LTE can solve the problems of limited bandwidth,susceptibility to interference,poor real-time performance and poor security of WLAN,which provides a feasible channel for more abundant services and is of great significance to the construction of new type of wireless communication in rail transit.