导　　师： 吴尽昭

学科专业： 080902

授予学位： 硕士

作　　者： ;

机构地区： 电子科技大学

摘　　要： 本文首先介绍了GPS及其他一些导航定位系统的发展历史,并阐述了当前导航定位产品的发展情况,重点分析了GPS导航定位技术对国内导航技术发展的重要意义。在此分析基础上,分析了GPS系统的导航接收原理、扩频技术理论基础,以及信号捕获的数字相关器核心技术。 本文的重点是研究GPS接收机信号捕获时的数据处理算法及其硬件逻辑电路结构设计。设计过程中,对于常见的捕获方法进行了理论上的概括、阐述。从理论上分析了它们的一些缺点,并因此提出了自己的信号相关算法。本文采用滑动相关算法,并结合FFT方法、长数据的非相干捕获理论,把信号的捕获分成两级运算,从而有效的捕获扩频信号。 设计中首先较为详细分析了算法,并利用Matlab中的Simulink工具包生成GPS中频信号,然后对算法进行了仿真分析,验证其算法的可行性,得到了仿真结果。然后就相关器的处理在FPGA中进行了针对硬件的详细设计,其包括了本地载波NCO、本地码生成器等各个模块,并针对数字相关器通道内部进行了详细的设计,这一硬件设计在Altera的Cyclonell平台上验证实现。 算法设计的仿真结果表明,本算法可以在同等的捕获条件和参数设置下,并且在高灵敏度的捕获情况下,最小捕获时间达到100ms,这样可以使得设备性能更优。 The thesis introduces the developing history of GPS and other navigation and positioning system, and describes the development of navigation and positioning products, then analyses the importance of the significance of GPS technology to the domestic navigation technology development. On the basis of this analysis, the thesis analyzed the GPS navigation receiver principle, and the basis of spread spectrum technology theory, and the core technology of the digital signal acquisition. This thesis focuses on the GPS receiver's signal acquisition, data processing algorithms and the logic circuit structure design. The thesis generalized the common capture theory in the design process, and analyzed their shortcomings. Then bring up a new signal correlation algorithm. In this thesis, we give a sliding correlation algorithm and combine it with the FFT method and the incoherent long data capture theory. The capture process of the signal was divided into two operator stages, and thus it can effectively capture the spread spectrum signal. In the design process, firstly, we gave an analysis of the algorithm in detail, and use the Matlab Simulink Kit to generate the GPS IF signals, and then simulate and analysis of the algorithm, verify the algorithm's feasibility and obtain the simulation results. We use the FPGA to design the hardware circuit for related processing in detail, which includes the local carrier NCO and the local code generator, then gives a detailed design of the digital correlator device's internal channel. This hardware design is verified by Altera's Cyclone II platform. The simulation results show that the maximum and average acquisition time of the new algorithm can reduce to100ms under the same parameter and acquisition condition and the high sensitivity capture mode. Thus, the equipment has a better performance.

关 键 词： 接收机 捕获 相关器

领　　域： [电子电信] [电子电信]