High Dynamic GPS Receiver Research And Implementation

With the advent and application of a variety of high-speed aircraft,GPS navigation will face a more complex and harsh environment in the future,such as high-speed,high dynamic,high noise,which have put forward higher requirements for the design of GPS receiver.This paper focuses on the acquisition and tracking strategies of GPS receiver in high dynamic environment,also has finished software simulation,hardware implementation and testing.The studies would provide the design of high dynamic GPS receiver corresponding reference.For the aspects of the high dynamic receiver's acquisition,the paper has compared the advantages and disadvantages of three existing methods: serial acquisition,FFT-based frequency parallel acquisition and FFT-based code parallel acquisition,Then analyzed their limitations in high dynamic environment;Has proposed a new rapid acquisition program based on Partial Matched Filter(PMF)and Fast Fourier Transform(FFT),which made frequency analysis range be extended to 30 KHz and acquisition time be shortened form tens of seconds to the millisecond level theoretically;For the aspects of the high dynamic receiver's tracking,Firstly,a separate analysis of the dynamic performance and noise performance of the PLL and the FLL has been done;then,the paper has designed a new high dynamic tracking loop program on the basis of the conventional combination loop program,which is second-order CPAFC auxiliary third-order PLL based on the traction of Four-Quadrant Frequency Discriminator(FQFD);In addition,tracking loop switching judgment conditions have been set up,and the optimization of selected value also has been given by simulation;the next work is improving the traction performance of FQFD algorithm.JPL(Jet Propulsion Laboratory)high dynamic model tests show that the performance of the combination tracking loop is stability.The Xilinx XC6VLX240 T and TI's DSP-the TMS320C6747 are used to achieve the high dynamic rapid acquisition receiver unit after the theoretical design.OLink Star NS700 simulator tests show that,in the dynamic environment where the acceleration is 9g,the jerk is 2g/s,the rapid acquisition receiver can be completed acquisition within 40 ms and quickly transferred to the tracking link,and the navigation data demodulation is in good condition.