Research And Implement Of Acquisition Algorithm In GNSS Receiver

Global Navigation Satellite System (GNSS) is widely used in the positioning and navigation, geodesy, the location and monitoring to marine vessels and vehicle and so on. The complex signal processing has been completed by synchronising the locally generated signals and the signals received.So fast and efficient signal acquisition are one of the key technologies to ensure that the receiver is real-time and high-precision.In this thesis, as the example of the Global Positioning System (GPS), there has a brief description of the GNSS system principle, analysis of the function modules of the receiver, and a brief introduction to tracking algorithms, focused on analyzing the acqusition algorithm.This paper analyzes and simulates the classical acquisition arithmetic, such as the serial search arithmetic in the time-domain and the FFT frequency-domain acquisition arithmetic. In high-dynamic condition,the higher requirement of acquisition algorithm is needed.Lastly, two new acquisition algorithms are proposed. One is the acquisition arithmetic which is based on maximum likelihood and working under the low SNR environment. The other is based on ingenious differentially coherent in time and frequency domain. Not only the real time-domain and frequency-domain parallel searching but also the high-sensitivity acqusition is realized.