WCDMA Wireless Coverage Technology Research Of High-speed Railway

In recent years China Railway High-speed develops rapidly. due to the influence of fast fading of fast moving process, Doppler Effect, the materials of the train, the disorder, can't connect, switch towards always happen. This phenomenon leads to users' perception degrees drop. Facing the increasingly user and user demand for perception degrees, How to provide good WCDMA network coverage for China Unicom in this high-speed environment provide, becomes an urgent question.For high-speed railway wireless coverage, with scenes and particularity of high-speed operation, strong body penetration loss, and the complex circumstance, here appears different kinds of difficult problems, such as the doppler frequency is too big, cause NODE-B transmit and receive frequency not consistently; High-speed operation cause switching frequent, the faster the longer distance switch, switching distance is beyond the original sector coverage, and the terminal can not receive the Switching signaling, lead to the drop; Hollow aluminum body makes the loss too big, loss of car coverage; Bridge tunnel special scene around more, lines and the cross make the networking complex, and the place such as the station, urban low covered with private network crisscross leads to access difficult, etc., are the research problems needed to resolve,if we can solve the problems above,it will greatly improved user high in high-speed railway on the experience of cell phone use,what makes users likely to play WCDMA cell phone instead of play others in high-speed railway,this will give China Unicom the huge economic value.this paper analysis why all above happen,and give the solution. Meanwhile,the distance of WCDMA coverage overlap is given innovativly in the article,and the link budget is given for the first time too,which solve the problem perfectly. From the recent tests of Shanghai-nanjing high-speed railway, receiving level value reached - 95dBm more than 96% ,which means the high-speed railway is covered perfectly.Finally, the results are given for all kind of analysis, for technical aspects of the various possibilities, what is likely to encounter in the actual networking, the subject give the answer, which is also helpful to the future's construction of high-speed railway coverage of WCDMA.Besides, how to optimize the network after the construction is also an important topic,which is not discussed,wait until later.