Research On Acquisition And Tracking Technology For High Sensitivity Satellite Navigation Receiver

With the development of satellite navigation technology,high-dynamic navigation receiver technology has been mature.However,in recent years,with the increasing demand of location-based services,especially in deep mountains,jungle,tunnels,indoor and other weak satellite signal environments,the research on high sensitivity satellite navigation receiver technology has become a hot topic.Based on the theory and practical application,the three-mode satellite navigation receiver in the weak signal environment acquisition and tracking technologies were studied in this paper.And the weak signal acquisition and tracking of the three systems(GPS?GLONASS?BeiDou)are realized with FPGA + DSP as the platform.Acquisition,tracking technologies are part of the signal baseband processing technologies,which are the basis of follow-up navigation calculation.Due to the different system navigation data structure differences,so the systems need to take different acquisition,tracking methods.This paper introduces the data structure of three systems and the commonly used acquisition and tracking methods.On this basis,the weak signal acquisition technology and tracking technology were studied and realized respectively.Firstly,the processing gain of coherent and non-coherent integrals are analyzed.Then,several algorithms which can effectively improve the signal acquisition sensitivity are analyzed and compared,and the acquisition methods and the concrete realization methods of the three systems are determined respectively.Finally,the actual effect of the programs are tested and the test results are analyzed.At the same time,the weak signal tracking technologies are studied,and the carrier loop and the code loop are analyzed and implemented.In order to cooperate with the subsequent positioning processing,this paper also proposed a weak signal data synchronization algorithm-K-P algorithm.The actual test of the receiver proves that:using the proposed methods,the acquisition and tracking sensitivity of GPS and GLONASS Systems reaches-145dBm and the acquisition sensitivity of BeiDou system reach-135dBm.