GPS数字中频信号的模拟

GPS Digital IF Signal Simulation

研究了GPS软件接收机中GPS数字中频信号模拟的基本原理。首先,介绍了GPS信号的调制过程;其次,分析了C/A码的产生原理,并分析了信号的数字化原理;再次,讨论了GPS信号中夹杂的噪声及GPS数字中频信号的模拟过程;最后,针对不同环境分别对GPS数字中频信号频谱进行了仿真实验。结果表明,其频谱比较准确。既能从图中看出调制过程,也能够求出其载波频率,为以后的研究奠定了重要的基础。

This article studies the basic principle of the generation of digital intermediate frequency signal in GPS software receiver.Firstly, introduce the modulation process of GPS signal, secondly, analyze the principle about C/A and process of signal digitization.Thirdly, discusses the noise, which exists in GPS signal, so as simulation process of GPS digital intermediate frequency signal.Finally, according to different situations, simulation experiments are made respectively on the GPS digital intermediate frequency signal spectrum; The simulation results show that： the spectrum is quite accurate; the modulation process can be seen from the graph, as well as carrier frequency. Come to the conclusion that this is a very important basic theory for the further research.