Research On Broadband Wireless Access Network Coverage And Handover For High-speed Railways

With the rapid development of High Speed Railways (HSR), more people would like to choose fast and convenient High Speed Trains (HST) as their transport. In order to meet passengers'demand for enjoying broadband communication service such as voice, video and games during several hours'journey, a lot of HST companies, communication operators and research institutions have been developing, deploying and testing broadband wireless access networks for HSR. The topic of high speed data services in high speed mobile environment has also been selected as the main research focus by the Ministry of Science and Technology and the Ministry of Railways in the "Eleventh Five-Year Plan". Therefore, it is significant to study the issues of broadband wireless access for HSR.Based on the requirement of broadband wireless access in high speed movement, this thesis focuses on the research of schemes of broadband wireless access for HSR, which can serve as a useful reference for future research and practice of broadband wireless access network for HSR. The research of this thesis mainly includes:Firstly, after a detailed comparison of domestic and international existing schemes of broadband wireless access for HSR, merits and faults of these schemes are pointed out and the applied background and restrictions of these schemes are described. In addition, a broadband wireless access network based on radio over fiber for HSR is proposed and the coverage effectivity of this scheme is analyzed. Furthermore, the method to analyze the relationship between the number of remote antenna units and roof antennas is illustrated using the analysis model, which can provide suggestion for the network planning. Finally, a reasonable scheme for medium access control is proposed and the seamless fast handover procedure is discussed in detail. In the implementation of fast handover strategy, dynamic and fixed slot resource allocation schemes are proposed respectively, and their performance is compared in simulation. The simulation results show that the dynamic scheme is better than the fixed scheme both for one user and the whole network.