摘要：随着经济水平和通信水平的不断提高，人们对于通信的需求越来越大。在通信技术发展的过程中, 为了使通信过程不受时空的限制, 人们把研究对象由开放空间转向限定空间。相对于自由空间，一些封闭的空间，例如:电梯、地下室、隧道、地铁等场合，通信的质量往往会受到干扰，而在隧道中无线电波的传播损耗尤为严重。通信距离已成为制约隧道内3G无线通信的关键问题，并且不同长度、形状的隧道，弯曲度不同的隧道，建筑材料不同的隧道，隧道内壁是否光滑都极大地影响着电波的传播损耗,而人们也已经在不断地改善。
本文主要研究了隧道中电磁波传播的基本特性，从理论上分析了电磁波在隧道中的传播规律。首先从介绍无线电波的发展史，简单分析了国内外目前无线电波的发展现状，然后介绍了窄带、宽带的传播规律，分别分析了大尺度衰落、小尺度衰落、快衰落三种不同衰落的特点，再介绍了无线电波传播规律一般的研究方法，包括统计方法、混合方法以及确定性方法。就理论的方法中详细介绍了矩形隧道波模理论以及射线跟踪法；实验的方法中由于考虑到价钱以及环境，人力与物力等因素的特殊性，本文简单介绍具体所需要的的设备。在最后就矩形隧道对4种不同横截面积下对接收功率与时延对不同位置收发距离通过MATLAB软件分别进行进行了仿真，得出了接收功率和时延对比图，验证了一些结论。关键词： 通信技术；无线电波；传播规律；矩形隧道；接收功率8371
Subway tunnel radio waves propagation prediction and simulation
Abstract：With the continuous improvement of economic level and communication level, people's demand for communication become more and more large. In the process of communication technology development, in order to make the communication process not limited by time and space, people turned to the object of study from the open space to the limited space. Communication distance has become the key problems of tunnel 3g wireless communication, different length, the shape of the tunnel, and the bending degree of different tunnel, building materials of different tunnel, tunnel lining are smooth or not will greatly influence the wave propagation loss, and now it has been in constant improvement.
In this paper, the basic characteristic of the electromagnetic wave propagation in tunnels is studied, the propagation rules of electromagnetic wave in a tunnel are analyzed theoretically. First from simple introduction to the history of radio waves, the paper analyzes the radio waves development present situation at home and abroad, and then introduces the propagation regularity of narrowband, broadband, respectively analyzes the large-scale fading and small-scale fading, fast fading characteristics of three different decline, then I introduce the radio wave propagation in general research method, including statistical methods, combined approach and deterministic approach. In the theory of the method I detailed introduce the rectangular tunnel mode theory and the ray tracing method. In experimental method, due to considering the price and the environment, human and material factors such as particularity, the paper simply introduces the specific needed equipment. In the end, to four different cross-sectional area in rectangular tunnel, the power and delay for different position and distance through the MATLAB software were simulated respectively, and contrast figure of the received power is obtained and the time delay, some conclusion was verified.
Keywords：Communications technology；Radio waves；propagation rules；rectangular tunnel；receive power ；
目  录
1  绪论    1
1.1 课题的研究背景以及意义    1
1.2 通信发展    1
1.3 国内外发展现状    3 MATLAB地铁隧道无线电波传播特性的预测与仿真:http://www.751com.cn/tongxin/lunwen_6666.html