【作者】 郑锐；

【导师】 冯振明；

【作者基本信息】 清华大学 ， 信息与通信工程， 2010， 硕士

【摘要】 全球定位系统(GPS)硬件信号源可以精确模拟接收机所接收的GPS卫星信号,用于对接收机的捕获、跟踪以及定位解算精度进行测量,为GPS接收机的开发和验证以及其他新技术的运用提供开发环境和测试验证平台。由于涉及军事保密领域,可参考的有用资料非常少,硬件信号源的研制在国内仍属空白,国外这类产品对我国是严格禁售的。但是GPS信号源的研制,尤其是硬件信号源的研制对于我国有效利用或对抗GPS系统,以及开发我国自己的卫星导航系统又有着非常重要的现实意义。本文根据GPS中频信号数学模型和软件仿真的结果,给出了GPS信号硬件模拟器的设计实现方案,主要信号产能的功能由一块基于CPCI总线的信号处理卡完成,另外为了使这个信号源具有一定的实时可配置性,采用了一块基于CPCI总线的控制器作为上位机。信号处理卡上的硬件采用了模块化设计,分为控制模块、信号发生模块和时钟管理模块,各模块协同工作并具备可扩展性。为了使得信号源产生的模拟信号能够高度接近目前的真实GPS信号,在信号源的实现方案中加入了包括P码发生、BOC调制和Interplex调制等关键技术,文中对这些技术做了简要介绍和讨论。还介绍了设计完成后的硬件信号源的整个工作流程。完成的信号源能够输出包含C/A码、P码和M码的中频或射频GPS模拟信号,并可以通过上位机实时配置信号码型、信号强度、调制方式、载波多普勒值和码多普勒值等多种参数。观察信号源产生的模拟信号频谱,与真实GPS信号频谱一致,再使用本身已得到验证的GPS硬件接收机对其信号进行验证,结果显示GPS接收机能够正常地完成捕获、跟踪和定位解算,定位解算的结果与真实用户位置误差在设计允许范围之内。这表明GPS中频信号硬件模拟器能够精确地输出高度接近真实信号的模拟GPS信号,可以对软/硬接收机的开发、应用和验证提供高质量的测量环境。更多还原

【Abstract】 Global Positioning System (GPS) hardware signal simulator can accurately simulate the GPS satellite signals which GPS receivers receive, it is used on the receiver’s capture, tracking and position estimation accuracy of measurement, for the development and validation of GPS receivers and other new technologies use of available development environment and test verification platform.The paper presents the GPS signal simulator hardware design scheme. the main function of signal capacity by the CPCI bus based on a signal processing card to complete the other in order to make the signal source has a certain Real-time configurable, using a CPCI bus based controller as a PC. Signal processing hardware on the card using a modular design, divided into control module, signal module, and clock management module, all modules work together and scalable. In order to make the signal simulator to simulate signal to a high close to the current real GPS signal, the realization of the signal simulator into the program, including P code occurred, BOC modulation and key technologies Interplex modulation. These techniques are briefly introduced and discussed. This paper also introduced the entire work flow after the completion of the design of the hardware.Completion of the signal simulator to the output contains the C/A code, P code and M code GPS IF or RF analog signals, and can be configured through the PC real-time letter code type, signal strength, modulation, carrier Doppler values, code Doppler values and other parameters. Has been validated using their own GPS receiver hardware to validate its signal, the results show that GPS receivers can normally complete the acquisition, tracking and position resolution, position resolution of the results and the real position error in the design to allow users within.更多还原