【作者】 张军；

【导师】 周小林； 帅涛；

【作者基本信息】 复旦大学 ， 电子与通信（专业学位）， 2014， 硕士

【摘要】 精确的导航主要依赖于精确的时间。在导航卫星系统中,精确位置的测量实际上是精确时间的测量,而精确的时间来自于精确的时频基准信号。高精度的卫星时频基准信号是整个卫星导航系统实现导航定位、授时和测速的基础。研究高精度的导航时频基准源生成技术,是各个国家基础研究的重点方向,对国家建设和发展意义重大。本文第一部分,介绍国内外导航卫星时频基准设备的研究发展现状,给出相关实现方法和技术指标。并在前人研究的基础上,梳理出下一代高性能导航定位系统时频基准设备的技术发展趋势。第二部分分析了时频信号的准确度、频率稳定度等关键技术指标,并给出相关指标的相互转化关系。在此基础上,研究基于数字锁相环DPLL和直接数字频率合成DDS相混合的导航高精度时频基准源生成技术,仿真产生高精度、高稳定度、低相噪和低杂散的基准信号,并分析其性能。作为原理样机设计的理论基础。第三部分是根据系统的功能和指标要求,提出一种可行的高精度时频基准源原理样机实现方案,将铷原子钟输出10MHz参考信号转换为高可靠、高精度、稳定并且连续的10.23MHz导航卫星时频基准信号,并进行软硬件实现。最后,针对原理样机的关键技术指标,进行测试验证,给出具体测试结果。更多还原

【Abstract】 Precise navigation depends on precise time. Actually, in the global navigation satellite system (GNSS) the precise position measurement is the precise time measurement, while precise time comes from precise time and frequency standard signal. High-precision satellite time and frequency standard signal is the base of navigation position, time transfer and velocity measurement in GNSS. Research on the technology of high-precision navigation time and frequency standard source production is the key orientation of national foundational research and contributes signally to national construction and development.In the first part, this article introduces the development status of navigation satellite time and frequency standard devices research both in domestic and abroad. The realization methods and technical indicators are also provided. Based on former research, it sorts out the development trend of next generation of time and frequency standard devices in high-performance GNSS.Part Two analyzes the key technical indicators such as accuracy of time and frequency signal, frequency stability, and shows the transformation relationship of relative indicators. As the theoretical basis of prototype design, the paper studies the navigation high-precision time and frequency standard source generation technology based on the mixture of digital phase-locked loop(DPLL) and direct digital frequency synthesis(DDS). Moreover, it simulates the generation of high-precision, high-stability, low phase noise and low spur standard signal and analyzes its performance.According to system function and indicator requirement, Part Three puts forward a practical solution of high-precision time and frequency standard resource prototype realization, which transforms 10MHz reference signal outputted by Rubidium atomic clock into high-reliability, high-precision, stable and continuous 10.23MHz navigation satellite time and frequency standard signal, and realizes it by hardware and software. Finally, aimed at the key technical indicators of prototype design, tests and verifies are made and the specific testing results are provided.更多还原