Research On The Td-scdma System Network Under High-speed Mobile Environment

TD-SCDMA network has come into commercial period by now in China. According to the 2010 network plan of CMCC, TD-SCDMA network will cover all the main cities of China by then and launch the national commercial operation.Another fact is that the railway speed in China has been accelerated for six times during the past decade and the speed of the main railway lines has been raised to 200km per hour. During the "11th five-year plan" period, China will further build 19,800 kilometers of railway lines, among which 5,457 kilometers will reach a speed of over 300km per hour.With the constant improvement of modern railway speed, the third generation of mobile communication technics as TD-SCDMA adapted to high-speed environments have become an indispensable part of mobile communication and is urgent to resolve.In this study, high-speed mobile communication applied to high-speed railways will be studied, combining with the TD-SCDMA network of China Mobile GuangDong Branch.Firstly, major factors that could influence the high-speed function of TD-SCDMA will be considered, basing on the experience of GSM, WCDMA and CDMA2000. Then, aiming at high-speed environments, propagation model and link performance will be tested mainly by analog simulation and verification test, so that parameters of propagation model and link budget could be modified. The plannings of base sites, radio factors, capacities are performed with the help of planning software according to the test results. Finaly, certain feasible network optimization programmes for the planned and constructed network will be carried out in order to improve the covering effect and quality of the network.In brief, basing on past research findings, this paper brings up an overall planning and optimization solutions for TD-SCDMA network within high-speed environments by studying the influence of high-speed environments on mobile communication, aiming to provide certain reference and guidance for high-speed communication network construction in future.