Study Of CDMA Wireless Networe Coverage Of High-Speed Railway

In recent years, the construction of the high-speed railway in our country has obtained compelling achievement of world interest, with several high-speed railways gradually opened, such as Shanghai-Nanjing high-speed railway, Nanjing-Hangzhou high-speed railway, and Beijing-Shanghai express railway, the communication of the high-speed railway has become the hot issue among academia and industry.This text had analyzed the environmental characteristic of the communication and its influence on CDMA network covering of high-speed railway-This paper introduced two methods of the CDMA network coverage, Special Coverage and Network Coverage, along the high-speed railway, and the two kinds of coverage were compared-At the same time, some key technologies of network coverage were introduced too, including the antenna and selection, station site selection, switch setting, the LAC/RAC planning, and so on. And the CDMA network covering suggestions and feasible technology along the line of the high-speed railway were proposed. In the text, the penetration loss of the train, the Doppler Effect and mobile communication switch in high movement circumstance were analyzed and the relevant mathematical modules were introduced. Combined with forward and reverse link budget for different scenarios, sit-building recommendations (including space between stations, grazing angle and so on) were given. According to the practical engineering problems encountered in the instruction of the jiangsu section of the CDMA network coverage of the Shanghai-Nanjing High Speed Railway, the test results of the previous coverage were listed, and the cases were analyzed. Base on the analysis, and combined with practical experience in engineering, those challenges were solved one by one. As the scene that the high-speed rail goes through is more complex, for further research, simulation and evaluation of communication system in different scene, and providing an important guarantee for the prototype design and link level simulation, it is necessary to bring out the accurate characterization of the radio channel for different scenarios. As the same time, the "line capacity" concept is introduced, based on the present capacity of trunk lines in in the traffic coverage model.The last part herein has carried on the analysis to the cover situation of the commercial intercity-high speed railway of Shanghai and Nanjing. The detailed test data and charts were given, and the performance is much better than the original network, and it achieve the desired effect.