摘要GPS(全球定位系统)能够在全球范围内提供实时定位和导航服务，方便用户查询时间、三维坐标和速度，在军事和民用领域得到了广泛应用。利用软件无线电原理设计GPS接收机因为其出色的灵活性成为GPS接收机的研究热点。64574

本文设计了基于软件无线电的GPS接收机。在介绍了GPS基本原理的基础上对C/A码的时域和频域捕获原理进行了比较，分析了频域捕获中输入数据的平均处理。接着研究了跟踪原理，包括伪码的码延迟跟踪环和载波的科斯塔斯跟踪环以及叉积自动频率跟踪环。然后介绍GPS接收机射频模块，编写程序实现芯片配置以输出所需的信号格式。最后结合通用FPGA(现场可编程门阵列)平台，对GPS接收机进行了数据处理框图设计和编程实现。对其中的C/A码生成、平均下采样、FFT、平方根算法和伪码跟踪等重点模块进行了Matlab验证和波形仿真。

毕业论文关键词  GPS接收机  捕获和跟踪  射频模块  FPGA

毕业设计说明书（论文）外文摘要

Title   GPS Receiver Design based on MAX2769                     

Abstract

GPS (Global Positioning System) can provide real-time positioning and navigation services across the world. Users can easily query time, 3-D coordinates and speed, GPS has been widely used in military and civilian fields. Software-defined receiver is becoming a research hotspot in GPS receiver design because of its excellent flexibility.

This paper introduced the GPS receiver designed based on software radio. This paper compares the differences on the C/A code capture, in the time domain and the frequency domain, based on the basic principles of GPS; introduces the averaging processing of the input data in capture. This paper studies the principles of the tracing, including PLL tracking loop of pseudo-code and Costas & CPAFC tracking loop of the carrier wave. This paper then introduces the RF module of the GPS receiver, gives codes for chip configuration to achieve the desired output signal format. Finally, this paper gives the GPS receiver block diagrams and the codes for data processing in FPGA (Field Programmable Gate Array). The C/A code generation, average down sampling, FFT, square root algorithm and C/A code tracking module are analyzed by Matlab and simulated of waveform.

Keywords  GPS Receiver  Acquisition and Tracking  RF module  FPGA

1  绪论 1

1.1  研究背景及意义 1

1.2  GPS接收机研究现状 1

1.3  论文内容及安排 2

2  GPS基本原理 4

2.1  GPS信号 4

2.2  GPS信号调制与解调 7

2.3  GPS接收机原理 8

2.4  本章小结 9

3  GPS信号的捕获、跟踪和同步 10

3.1  GPS信号捕获 10

3.2  GPS接收信号的平均下采样 12

3.3  本地复现C/A码处理 13

3.4  伪码跟踪环 13

3.5  载波跟踪环 14

3.6  GPS导航数据的位同步和帧同步 18

3.6  本章小结 18

4  GPS接收机射频模块实现