GPS P码接收机本地信号发生器的FPGA实现

摘要

As the military use of GPS,P code is famous for its characteristic of high precise,long period and complex structure. The software receiver based on P code is not only of high position precision, but also of high level of anti-jamming and anti-spoofing. It is of great importance for direct P code acquisition and the tracking if we can generate any bits of P Code in its period. After doing research on the mechanism and structure of P Code generation, we designed some algorithm of P code and realize it through MATLAB. Then we propose the algorithm for FPGA by modules including register module, delay module,period module and register phase module. The result shows that P Code of any time or any satellite can be generated by it without time delay.%P码作为GPS军用伪码,具有结构复杂、周期长且码速率快的特点,这使得使用P码的软件接收机不仅定位精度高,且具有很强的抗干扰和反欺骗能力.能够实现任意卫星的任意时刻P码的产生,对于实现P码直接捕获和跟踪有很重要的意义.对于P码的产生原理和结构进行了分析,基于MATLAB设计了相应的P码发生算法并进行简单的算法仿真.之后针对FPGA硬件平台对P码发生器进行了相应的模块设计,包含寄存器模块、延时模块、周期控制模块和寄存器相位模块等.测试实验结果表明P码发生器可以基本无延迟地生成任意卫星、任意时刻的P码.