GPS C/A码发生器的仿真研究与FPGA设计

全球定位系统（Global Positioning System,GPS）能够向全球范围内的用户提供全天候的高精度导航、定位和授时服务,在军用和民用领域得到了广泛的应用.以GPS系统的测距码粗码C/A码为研究对象,在深入研究C/A码信号生成原理的基础上,利用Matlab中的Simulink对C/A码信号的生成进行了建模、仿真和分析,并利用FPGA设计并实现了C/A码发生器,详细说明了C/A码生成的设计原理,对其中的关键模块进行了设计和分析,给出了具体实现方案,同时阐述整个应用程序的流程,设计采用抽头选择控制端设置产生不同GPS卫星号的C/A码,最终仿真进一步验证了其结果的正确性,它可以产生任意GPS卫星号的C/A码,设计中采用VHDL语言实现的C/A码程序,可应用于基于FPGA的GPS接收机设计中,对研究我国的北斗导航系统接收机有一定的借鉴意义.

Simulation of GPS C/A code generator and design based on FPGA

The domestically designed GPS navigation satellite system has the ability of navigation, positioning, timing. GPS has been used in various fields including military affairs, navigation, aviation, measurement, transportation and surveying and so on. Based on fl signal frequency ranging code generator of GPS, the model is set up and simulated with Matlab simulink. And GPS C/A code generator is designed and implemented using FPGA, the design principle of ranging code generator is also particularly presented and the key modules are designed. Then, the implementation plan is given out in detail. At the same time, the flow of application program is expounded. Phase-select control port is designed to set different taps to generate different ranging code of different GPS satellite. And the simulation results show that the design of GPS C/A code generator can generate ranging code of corresponding different GPS satellite. The C/A code generator is designed using VHDL language, and it can be applied to GPS and Compass II receiver design.