Research On Vector Tracking Technology In Navigation Signal

With the deepening and improvement of navigation technology,navigation receivers have been more and more widely applied,and users’ requirements for navigation receivers’ performance are also increasing.The traditional receiver tracks each satellite signal on one channel separately,and do not make full use tracking information of other channel,resulting the tracking performance cannot be guaranteed in the loss of satellites and dynamic environments,so traditional scalar tracking receiver is difficult to meet the actual needs.Vector tracking is a tracking algorithm that can improve receiver performance.The vector tracking algorithm integrates the tracking channel with the positioning solution process,combines the measured values of each channel,calculates the information of each channel through the navigation filter and feeds it back to the tracking loop.Vector tracking make full use of the correlation of each channel to improve the tracking performance.Aiming at the shortcomings of scalar tracking algorithm,a vector tracking algorithm with third-order frequency-locked(FLL)loop auxiliary fourth-order phase-locked loop(PLL)is proposed,and its performance is tested and analyzed.The main research contents are as follows:Firstly,the structure and characteristics of navigation signals are analyzed,and scalar tracking algorithm is introduced from the aspects of carrier tracking loop and code tracking loop.On the basis of scalar tracking,foucs is set on the vector tracking algorithm,including the difference between vector tracking algorithm and scalar tracking algorithm,the initialization process of vector tracking algorithm,the loop structure of vector tracking and the vector tracking navigation filter model.Secondly,based on the principle of carrier tracking and vector tracking,a vector tracking with third-order FLL auxiliary fourth-order PLL is designed.In this algorithm,the third-order FLL auxiliary the fourth-order PLL as a carrier tracking loop to track the carrier,and verified the feasibility of the carrier tracking loop by simulation.A vector delay lock loop is used for the code tracking loop,a second-order position model used for the state model of the navigation filter,and the error of the discriminator is used for measurement equation.Finally,from the three aspects of static,retracking and dynamic performance,the vector tracking algorithm of third-order FLL auxiliary fourth-order PLL is tested,and compared with algorithm with the scalar tracking algorithm and vector tracking algorithm with the second-order FLL auxiliary third-order PLL.The results show that the tracking error of the algorithm is less than that of the above two comparison.Compared with scalar tracking algorithms,localization performance are superior to scalar tracking algorithms and compared with second-order FLL auxiliary third-order PLL algorithms,re-tracking ability while a satellite signal is blocked and recovery are more excellent.