Research On High-speed Railway CDMA Network Planning And Optimization Technology

With the development of high-speed railway,the high-speed railway communication has beenreceived more attention.Because of its high speed and good tightness, the high-speed railway causethe wireless communication challenges,facing strong Doppler frequency shift, obvious bodypenetration loss and frequent cell switching.The paper illustrates the theory of CDMA and combines with the high-speed railway CDMAnetwork construction experience, analyzes the challenges of the high-speed railway wirelesscommunication,including the Doppler shifts, the penetration loss, fast cell switching and variouscommunication scenes.Besides,the thesis summarizes the general practices in CDMA wirelessnetwork construction under the high speed circumstances which include link budget, coverage theplanning, networking strategies, cell switching setting, capacity planning and site selection.On thisbasis,the paper in combination with the construction of Jiangsu high-speed railway in CDMAnetwork,and discusses several methods of the solution to the high-speed railway wireless networkcommunication problems.In the thesis,it illustrate the different strategies in different scenarios,suchas under the elevated bridge, tunnel and the " U " type groove and other special scene.According tothe different scenes of the former and the reverse link budget,the paper gives the coverage of acell,through the analysis of train speed and the handoff latency in different scene,the paperillustrates the switching overlap area size and according to the " line capacity " of differentscene,the paper gives the capacity planning of CDMA20001X（the first stage of CDMA2000,which belongs to the2.5generation technology）and CDMA20001X EV-DO（data only，enhancedtechnology of1X system） business in short-term and long-term.According to the Jiangsu high speed rail planning and design scheme of CDMA network indetail, based on the site survey, the article use the Enterprise (3G) simulation software of Aircomcompany to simulate the science,and the simulation verified the feasibility of the planningscheme.After the operation of high-speed railway, the author has test the actual network, andthrough the analysis of the test data, proving that Jiangsu high-speed railway CDMA wirelessnetwork construction project to achieve excellent coverage.