文档介绍：上海交通大学
硕士学位论文
GPS伪卫星的设计和实现
姓名:李实
申请学位级别:硕士
专业:导航、制导与控制
指导教师:战兴群
20070201
摘要

GPS 伪卫星的设计和实现

摘要
全球定位系统(GPS)可以向全球用户提供位置、速度和时间信息,在
航空、航天、海上及陆地等诸多领域得到了广泛的应用,成为一种主要的
导航手段。但是 GPS 系统的高精度、可靠性和完好性等诸多优越性都依赖
于跟踪的可视卫星数和卫星的几何分布。GPS 卫星在受遮挡时难以发挥作
用,在一些特殊地区如矿区、隧道、室内和地下,这些地方由于视野不开
阔或无法接收到 GPS 信号,满足不了定位要求。GPS 伪卫星是解决这些问题
的一条有效途径。
本文研究 GPS 伪卫星定位技术。首先综述了卫星导航系统的发展、现
状及存在的问题,介绍了 GPS 伪卫星的研究发展历史。针对 GPS 伪卫星定
位系统的设计,提出了 GPS 伪卫星发射器的基本功能,并详细研究了 GPS
伪卫星信号传输理论。
在理论研究和分析的基础上,设计了 GPS 伪卫星发射器。系统采用
RS232 与主机连接,使用先进的 SOPC 技术,以 FPGA 为平台,用 C 语言和硬
件描述语言实现了信号控制及中频调制,并用射频模块将信号的频带搬移
到 GPS 发射频率,最后通过天线将信号发射。
在中频测试部分,用仿真程序和示波器对 GPS 伪卫星的基带/中频信号
进行了试验验证。试验结果表明,设计的模块满足设计要求。
关键词:全球定位系统,伪卫星,软件无线电,现场可编程门阵列
第 II 页
ABSTRACT
The Design and Realization of GPS Pseudolites

ABSTRACT
GPS can provide us location , speed and time with high precision.
Nowadays, it has been widely used in many fields; especially in military field,
and it has e a kind of main navigation method. But, its high precision,
reliability and integrality depend on the number of visible satellites and their
geometrical distribution. GPS satellites may e unuseful when signals are
obstructed. In worse conditions, such as mine areas, tunnels and some places
indoors or underground, GPS receiver can hardly receive the signals from the
satellites. The signals are too weak to be used for positioning. In this case,
pseudolites can solve this problem.
This paper investigated the technology of GPS pseudolites system. Firstly, it
summarized the development, the present state and the existing problems of
satellite navigation system. And then it presented the research and development
of GPS pseudolites. During the description of GPS pseudolites system, the basic
function of pseudolites emitter was also introduced. And the paper gave us a
detailed account of the transmission link.
A kind of pseudolites emitter was designed on the basis of theory study and
analysis. The system li