低轨道卫星移动通信系统方案

摘要

作为一种国家关键的基础通信设施，以及全球移动通信的有机组成部分，卫星移动通信系统在国家安全、紧急救援、互联网、远程教学、卫星电视广播以及个人移动通信等方面得到了广泛的应用。新一代宽带卫星通信系统可以提供个人电信业务、多信道广播、互联网的远程传送，是全球无缝个人通信、互联网空中高速通道的必要手段。近年来卫星通信新技术不断发展，特别是低轨道卫星移动通信系统受到了人们的广泛关注，其研究与应用已成为各国的战略发展重点。无线资源管理是低轨卫星移动通信系统研究中的一项重要内容，这主要是由于卫星系统的资源是非常昂贵的，因此如何合理而有效地管理并利用卫星系统的资源已成为关键。

通过对低轨道卫星无线通信信道的基本特点的研究，文章具体从无线信道的缺点进行分析，并进行了matlab仿真模拟，得出信号经过多径信道的幅频特性，多径信道对不同频率信号的衰减情况不同，即具有频率选择性，以及信号经过多径信道的衰减情况，以及码元间隔对传输信号的影响，信号的码元间隔必须远大于信号的时延差，才能尽量的减小码间干扰。

关键词：低轨卫星通信，信道，信道特性

Abstract

As a national key infrastructure communication, as well as an organic part of the global mobile communications, Star mobile communication system in national security,emergency rescue, Internet, satellite TV broadcasting, remote teaching and personal mobile communication has been widely used in such aspects. A new generation of broadband satellite communication system can provide personal telecommunication business, multicasting, remote transmission, the Internet is a global seamless personal communications, high-speed Internet air passage means necessary. Satellite communication technology development in recent years, especially in low orbit satellite mobile communication system has received the widespread attention, its research and application has become a national strategic priorities. Wireless resource management is the study of Leo satellite mobile communication system is an important content, this is mainly due to the satellite system resources is very expensive, therefore how to reasonable and effective management and use of the resources of satellite system has become a key.

Through the low orbit satellite studies the basic characteristics of wireless channel, the article specifically from wireless channel faults is analyzed, and the matlab simulation, it is concluded that the signal after a multipath channel amplitude frequency characteristics, multipath channel attenuation is different on different frequency signal, which has the frequency selectivity, as well as the attenuation of the signal through the multipath channel, and the influence of element spacing to transmission signal, the signal of the symbol interval must be greater than the signal delay is poor, can try to reduce intersymbol interference.

KEY WORDS: LEO satellite， Channel，Channel characteristics

目录

第一章绪论 (1)

1.1 课题研究背景 (1)

1.2 低轨卫星移动通信发展概述 (2)

1.2.1 低轨卫星移动通信现状 (2)

1.2.2 低轨卫星移动通信发展历程 (3)

1.2.3 低轨卫星移动通信在个人通信中的地位 (4)

1.3 本文研究内容及章节安排 (5)

第二章低轨道卫星移动通信系统 (6)

2.1工作原理 (6)

2.2 低轨卫星移动通信系统 (6)

2.3 低轨卫星通信系统的优缺点及其话务量特点 (7)

2.3.1 优点 (7)

2.3.2 缺点 (8)

2.3.3 业务量分布的特点 (8)

第三章无线信道 (8)

3.1 无线信道特性 (9)

3.2 多径传播 (9)

3.3多径衰落 (9)

3.3.1定义 (9)

3.3.2产生原因 (10)

3.3.3主要分类 (11)

3.4 多普勒频移 (13)

3.41 概述 (13)

3.42 发生原因 (13)

第四章多径传播的模拟实验 (15)

4.1 实验目的 (15)

4.2 实验原理 (15)

4.3 实验内容 (15)

4.5 实验心得 (20)

结语 (21)

致谢 (22)

参考文献 (23)