Development of Real-Time Software GPS Receiver using Windows Visual C++ and USB RF Front-end

摘要

This paper contains the research about the development of real-time PC-based software GPS receiver. CPU in general purpose computer is able to deal with larger data processing than FPGA (Field-Programmable Gate Array) or DSP (Digital signal processor) and provides more comfortable debugging environment of commercial development tools than that of embedded system. It is also flexible for new GNSS signal policy and for development of sensor integration system. rnIF (Intermediate Frequency) data is collected from SiGe USB RF Front end - GN3S v2. The software receiver is developed using Visual C++ 2008 program tool on Windows XP. For reducing redundant works, Intel Math Kernel Library for FFT calculation and MFC (Microsoft Foundation Class library) for multi-threads and data management scheme are used. In addition, GNU GPL (General Public License) USB library is used for USB hardware control. rnThe real time software GPS receiver is composed of three threads which are USB control thread, GUI (Graphic User Interface) & display of receiver status thread and signal processing control thread. USB Data Control thread contains USB configuration, data stream control and saving down-converted IF data stream to data buffer. GUI thread contains displaying receiver status and receiving user command. In signal processing thread, whole stages of signal processing including acquisition, tracking, and navigation are implemented.