The Single Frequency Networks Optimization Of High Speed Railway Mobile Television And Performance Analysis Of The Receiving Terminal

At present, In the progress of the construction of high-speed railway , the corresponding quality of service should also be improved, and install the digital mobile TV in high-speed train is important part to enhance the quality of service, so the construction of high-speed railway mobile TV single frequency network in the future is an important part of railway's building , so it is a important issue that how to effectively construct the single-frequency network, how to optimize the SFN(Single Frequency Network) and how to deal with SFN overlap multi-path interference and the additional deterioration of signal to noise ratio to facing in the future.In this paper, we make an analysis of digital transmission standard ADTB which is relatively new in mobile TV, and carry out quantitative analysis on basic topology structure of single-frequency network, make the difference between modern digital television signals and analog TV signal coverage of the past, propose the reasons for network optimization, the targets, objectives and the general process and the current in the antenna of mobile communication technology.Then, we make a detailed analysis on the power gain of mobile TV single frequency networks overlap, and suggest corresponding optimization method combined with the analysis. Briefly introduced basic principles of single-frequency network and related issues that is must be paid attention to when construction of single-frequency network, give the basic framework in construction of railway mobile TV single frequency networks, focus on analysis of distribution of power gain in single-frequency networks overlap and analyze the testing results of Nanjing - Wuxi experimental section in mobile TV single frequency networks by using this characteristics and space propagation model of Okumura-Hata, verify the distribution of power gain in the single-frequency network and the reasonableness of Okumura-Hata model in construction of single-frequency network, raised several questions such as how to optimize the blind spots that found in SFN and the problems that pay attention to when in optimizations.Finally, according to the characteristics of high speed railway single-frequency network that analyzed in this paper and the problems found in testing, proposed a reception terminals that make good performance under the circumstances of multi-path interference of overlapping coverage areas and in the situation of the additional deterioration of signal to noise ratio can not improved, it can effectively reduce the multi-path interference and the deterioration of signal to noise ratio in the Single Frequency Network overlapped coverage area, make a better performance on the mobile TV of high speed railway single frequency network, reach optimization of mobile TV single frequency network.