Study Of Tracking Technique For High Dynamic GPS Receiver

GPS is an exact satellite navigation system, it has many merits, for instance, high precision, all weather and globosity, so it is regarded and applied in military and civilian domain widely. Owing to facing users, GPS receiver has great development and new productions appear ceaselessly and the frequency of update expedites.It is the precondition of normal movement that the system can track satellite signal steadily in GPS receiver, so the tracking technique is a disquisitive emphases all along. In the high dynamic condition, the received satellite signal takes Doppler frequency shift by carrier high-speed movement, and the frequency shift may attend by acceleration and quadric acceleration, it causes the change of carrier wave frequency and pseudocode delay, it is key to settling the question that how let the carrier wave and the pseudocode of receiver keep synchronization with the carrier wave and the random code of GPS signal.The thesis analyses the structure of spatial GPS signal firstly, afterward in the base of Phase Locked Loop, analyses the the algorithm of phase discriminator and frequency discriminator in carrier wave loop and the algorithm of phase discriminator in code loop, accomplishes comparison to all algorithm by simulation, introduces the principium of the filter of loop and numerical controlled oscillator. It analyses the origin of measure error in loop, on the base, bring the way about choosing tracking threshold and loo(?) bandwidth. Lastly, the thesis gives two tracking loop schemes to adapting high dynamic circumstance according as the assistant of frequency locked to phase locked, proves the validity and rationality of the schemes by simulation, and solves the question of carrier wave and pseudocode synchronization in condition of carrier movement with the acceleration and quadric acceleration.