高铁上的无线通信ppt

Hello ，everyone, today, my topic is the wireless communications on the high-speed railway , in recent years, the rapid development of high-speed rail has brought great convenience to our lives, high-speed rail not only faster, and better environment. But I found when When I was on the phone with others on high-speed railway, call quality is bad. , Often dropped or could not hear each other's voice, at the time when networking browse pictures or watch videos, there will be a buffer out, browsing is not smooth, and download data is particularly slow, communications experience is not good,

然而，我的研究方向就是当用户移动速度很高的时候，提高通信质量，保证用户能象在陆地上一样保持稳定的通信

However, my research direction when the user's movement speed is very high, improve the quality of communication, ensure that the user can keep steady communication as on land

信道是无线通信设计的基础，因此，无线信道建模成了我研究方向的主要内容。一般的信道模型如ppt 所示：

在这个等式中，等式左边代表接受矢量。X 代表发射矢量，H 代表信道矢量，n 代表噪声矢量，在通讯系统中，x 为用户或者基站发送的数据，y 代表用户或者基站接收的数据。解决高铁上无线通讯的问题最主要的是要准确建立高铁上无线通信的信道模型

然而高铁上信道模型的确定就是一个棘手的问题

Channel is the basis of the wireless communication design, therefore, the wireless channel model is the main content of my research direction. The general channel model as shown in the PPT:

In this equation,the left on behalf of the reciever vector. X represents the transmitter vector, H represents the channel vector, vector n for noise in communication system, X or base station to send data to users, and y represent user or base stations to receive data. Solve the problem of high iron on wireless communication is the most main is to accurately on high-speed wireless channel model is set up

However, the determination of high-speed rail on the channel model is a thorny problem。

Scene Partitioning for HSR

Special HSR scenarios such as cuttings, viaducts, tunnels, and

crossing bridges have significant impacts on the propagation characteristics. However, these HSR scenarios have rarely been investigated. Few channel measurements and standard channel models have actually been developed.

Channel Measurements at High Moving Speeds

无线信道本来就受很多因素影响，例如多普勒效应，路径损耗，多径效应，阴影效应，等等但由于高铁速度特别快，所以这些因素的考虑就特别麻烦，高铁信道测量是需要耗费大量人力和物力的工作，并且由于高铁经过的环境类别多，相同类别的场景存在较大差异等特点，在某一个场景中测量出来的结果不见得和该类别其他场景相符。

Wireless channel is affected by many factors, such as the doppler effect, the path loss and multipath effect, the shadow effect, etc. But as a result of high iron special fast so consideration of these factors is particularly troublesome

High-speed channel measurement is work requires a lot of manpower and material resources ，And because the high-speed rail after more than environmental categories, there are large difference between scenario of the same category, etc。In one scene of measured result doesn't fit the category its his scenes。