铁路无线通信系统GSM-R越区切换设计+代码

摘要 GSM-R(GSM for Railway)是一种建立在GSM（全球移动通信系统）基础之上专门应用在铁路上的通信技术, 应用范围越来越广，正不断推动铁路通信的发展。在我国，GSM-R也得到了迅速的发展。列车运行的安全性和可靠性直接取决于GSM-R，无线覆盖与越区切换技术是 GSM-R系统的关键技术，因此对其研究非常有必要。本文首先从理论上就无线网络覆盖的结构、使用方式进行了论述，划分出了单层无线覆盖和双网冗余无线覆盖，并对其进行比较。其次，分析了越区切换的流程（测量-触发-选择-执行），简单研究了有关越区切换掉话率和阻塞率的问题，并且提出了解决的方案。最后，构建了无线信道的模型（路径损耗模型和阴影衰落模型），在此基础上提出了一种基于 PBGT（功率估计）的提前切换算法。由于切换门限值、列车的速度、可用切换时间等要素的影响，对该算法进行了适当的改进。同时应用Matlab 仿真软件对两小区进行了仿真，并得到了仿真模型，说明该算法经过改进后能够有效地改善 GSM-R系统的性能。 37433
毕业论文关键词: GSM-R 无线网络覆盖越区切换功率估计
Abstract GSM-R (GSM for Railway) is a kind of based on GSM (global system for mobile communications) based on the special application in Railway communication technology, application scope is more and more widely, are constantly promote the development of Railway industry. In our country, the GSM-R also got rapid development. Train operation safety and reliability directly depends on GSM-R, wireless coverage and handoff technology is an important aspect of GSM-R system key technology, so the research is very necessary. This article first theoretically and the structure of the wireless network coverage, use methods discussed in this paper, pided into the single wireless coverage and dual network redundancy wireless coverage, and carries on the comparison. Secondly, analyzed the handoff process (measurement - trigger - select - execute), dropped the simple research about the handoff and model.next problems, and puts forward the solutions. Finally, construct the model of wireless channel (path loss model and shadow fading model), on this basis, put forward a kind of based on PBGT (estimated) power switch algorithm in advance. Due to the switching threshold method, train speed, switch time available, the influence of such elements as appropriate for the algorithm improvement. At the same time, application of Matlab software simulation simulation model were obtained, on the two plots show that the algorithm can effectively improve after improved GSM-R system performance.
Key Words: GSM-R Wireless Network Coverage Handover Power Estimation
目录
摘要.I
Abstract..II
1引言1
1.1研究背景..1
1.1.1列车无线通信技术..1
1.1.2GSM-R系统介绍.1
1.1.3国内外GSM-R的发展2
1.2论文研究意义.2
1.3论文的结构安排..2
2铁路GSM-R无线网络覆盖与实现.4
2.1GSM-R的网络结构..4
2.2GSM-R无线覆盖方式5
2.2.1单层无线网络覆盖..5
2.2.2双网冗余无线覆盖..6
3越区切换设计.8
3.1越区切换流程分析..8
3.1.1测量过程..8
3.1.2触发过程..8
3.1.3选择过程.10
3.1.4执行过程.10
3.2切换掉话性能分析.12
3.2.1切换引起呼叫掉话原因13
3.2.2切换掉话率分析13
3.2.3切换掉话问题的解决..14
3.3切换阻塞性能分析.15
4基于功率估计（PBGT）的提前切换算法.17
4.1无线信道模型17
4.2基于功率估计(PBGT)的提前切换算法.19
4.3基于功率估计(PBGT)的提前切换算法的改进20
4.3.1改进的原因..20 铁路无线通信系统GSM-R越区切换设计+代码:http://www.youerw.com/zidonghua/lunwen_36179.html