【作者】 董渊文；

【导师】 官洪运；

【作者基本信息】 东华大学 ， 通信与信息系统， 2007， 硕士

【摘要】 导航GPS接收机扩频接收算法的关键技术主要有五项，依次为GOLD码捕获技术、GOLD码跟踪技术、载波跟踪技术、位同步技术和帧同步技术。其中，信号的捕获、码跟踪、载波跟踪是GPS接收机正常工作的基础。不同场合GPS应用的不同，除了体现在应用处理模块的算法上有所不同外，主要区别在于GPS信号的捕获与跟踪方面的性能要求。所以可以说GPS信号的捕获和跟踪技术是GPS接收机的核心技术。因此，GPS接收机中的码捕获、码跟踪、载波跟踪技术是高动态GPS接收机研究的重点，也是研究的热点，高动态GPS接收机与普通GPS接收机的区别也在于此。由于此技术对于各种扩频接收机都有借鉴意义，所以有重要的研究价值。课题针对GPS信号在高动态环境中的特点，研究了应用于高动态GPS接收机的扩频接收算法，包括GPS信号的码捕获、码跟踪、载波跟踪、Costas环解调等环节的关键技术，提出了一套实现高动态下GPS信号接收的算法方案。在码捕获方面，对适应于高动态环境下的多种码捕获算法进行了探究和比较，提出了试用于GPS码捕获中的序列估计算法，对FFT算法在高动态GPS码捕获中的性能进行了深入的研究，对多种方法的各自优劣进行了探讨，并建立仿真模型进行了验证，最后选用FFT捕获法作为理想的GPS码捕获算法；在码跟踪方面，针对高动态的环境，选用能分离载波的超前滞后码跟踪环做为GPS信号码跟踪环路并分析了其工作机理及在GPS接收中的具体应用，学习使用了Matlab建立了比较复杂的系统模型，模拟GPS信号环境，进行了深入的码环性能研究，得到载噪比、环路带宽参数设置和码片跟踪误差的关系；在载波跟踪方面，采用CPAFC算法实现GPS信号载波跟踪环节，建立了Matlab仿真模型，模拟高动态的载波环境，得到了不同的环路带宽下，载噪比与频率跟踪误差的关系，以上对实际的GPS接收机参数设置有参考价值；使用Matlab和Xilinx辅助工具建立了Costas环路仿真模型，进行了功能验证。最后经过综合的调研，提出了一套与扩频算法相适应的硬件设计方案，并根据现有的实际条件，进行了相关实验。更多还原

【Abstract】 According to the characteristic of GPS signal under the high dynamic environment, the research is concentrating in the receiving algorithms of spread-signal of high-dynamic GPS receiver, which is including PN code acquisition algorithm, code tracking algorithm,carrier tracking algorithm and costas loop algorithm. The plan of receiving algorithms of spread-signal of high-dynamic GPS receiver is advanced. In the field of code acquisition algorithms, several code acquisition algorithms which can be used in high dynamic environment has been researched and compared, the sequential acquisition algorithm in GPS is advanced and the FFT algorithm in GPS is researched. Eventually, FFT acquisition has been chosen as the ideal GPS signal acquisition algorithm. In the field of code tracking algorithm, according to high dynamic environment, the code tracking algorithm which can separate carrier has been used and researched its performance in GPS, and made a complicated system mode by Matlab, analyzed its code loop paramter.In the field of carrier tracking loop, the CPAFC loop has beened used,researched and made a model by Matlab. A costas loop model is also made. Through a series of research, the plan of hardware which is related with the algorithms above has been advanced and experiments have been made according to current condition.更多还原