Research On Algorithm Of GPS Software Receiver And Implementation

With the rapid development of the Global Navigation Satellite System, there is a growing tendency among the researchers who focus on realization of GNSS software receiver. Because of its advantages such as its easy reconfiguration characteristics of function module and easy to change property of signal processing module, the Software defined radio based receiver has been regarded as a hot research subject. GPS software radio receiver is developed for its advantages on modularization, programming, flexibility and adaptability. Also it is compatible with a variety of navigation systems. The study on GPS could provide reference for Chinese BD navigation system.In the paper, the principles of GPS software receiver based on software radio are researched, and the algorithms for baseband signal processing and positioning resolution are mainly focused on. Firstly, the system architecture and the principles of GPS are introduced; then the signal format and modulation. Secondly, in order to obtain the navigation data, C/A code phase and Doppler frequency shift, the algorithms of baseband signal processing are discussed, including acquisition and tracking. Then, the algorithms of positioning resolution are analyzed. Navigation data and pseudo range are acquired from baseband processing results, thus user position would be calculated. Finally, a software radio receiver is implemented by using the C++ programming language, according to the analysis of the modules'properties of the hardware receiver and the theory of OOP.