基于数据文件读取的GPS信号模拟技术  

GPS simulation based on reading data file

作　　者：单庆晓[1] 陈建云[1] 钟小鹏[1] 杨俊[1] 

机构地区：[1]国防科技大学机电工程与自动化学院仪器科学与技术系,长沙410073

出　　处：《电子测量与仪器学报》2009年第5期79-84,共6页Journal of Electronic Measurement and Instrumentation

摘　　要：介绍了一种基于数据文件读取的GPS信号模拟技术。采用专门的软件系统产生包含GPS电文和观测数据的数据文件,再作为文件存储在SD卡上。仿真时读取导航电文和相应的伪距,同时产生多星的伪码,实现导航电文的调制。伪距的延迟通过数字延迟滤波器实现。最后通过正交调制的方法得到GPS射频信号。当数据文件改变时,GPS模拟信号也随之改变。信号处理的主要功能由一片FPGA实现。所有的信号模拟功能均集成在一块电路板上。该信号模拟器可以满足部分GPS接收机的测试需求。This paper proposes GPS simulation based on reading data file. The data file including GPS NAV data and pseudo-range data is generated by special software. After the data file is generated, it is stored in SD card. While the simulation is carried out, varied SV pseudo number are generated, GPS NAV data and pseudo-range data are read, so NAV data is modulated. The pseudo-range delay is realized by cascaded digital delay filter. At last, the simulated signal is modulated to 1575MHz. The simulated GPS signal is determined by data file. All simulation function is integrated on a single FPGA board. The prototype can meet the test requirement of some GPS receivers.

关 键 词：GPS信号模拟 数据文件 FPGA 

分 类 号：P127.1[天文地球—天体测量]