Reseach On Marching-on In-time Scheme And The Fast Algorithm Of Time Domain Integral Equation

Satellite navigation systems are currently being used in various industries focus on project,Countries around the world are actively build their own independent satellite navigation system.Currently, the global satellite navigation system includes a GPS system, Galileo, GLONASS system and China’s Compass navigation system, which plays an important role in positioning, navigation and other areas of life in which each country to serve the military and the people of the world.In high dynamic environment, the carrier’s high-speed, high acceleration and high-jerk caused by the Doppler shift to the navigation signal capture, tracking and positioning brings a great challenge, which has been a research concern receiver algorithms problems. This article is mainly for high dynamic environment, research institutions under TMBOC modulation method for tracking loop design, research and achieve stable eliminate dynamic tracking algorithm, then the algorithm using MATLAB detailed simulation and verification.This paper introduces the principle of GPS positioning system and the principle of TMBOC modulation and proposes high dynamic environment made waves generated tracking loop in tracking the Doppler shift change issues, analyze the impact of high dynamic tracking loop caused. On this basis, the topics for research in the following areas:(1) a detailed description of a typical high-dynamic model and signal model, and its velocity, acceleration and jerk made the simulation results show, and the establishment of a high dynamic mathematical model of the received signal.(2) describes the signal tracking loop carrier tracking loop and code tracking loop of the basic structures and algorithms, and specific modules inside a detailed analysis of algorithms, and the theoretical analysis and simulation of its measurement error.(3) Since the phase or frequency discriminator based and carrier tracking loop filter programs or traditional phase-locked loop frequency-locked loop technology used is based on the optimal criteria are not designed, so loop performance is very restricted. In the high dynamic environments, the navigation satellite navigation receiver and the ground is unstable in terms of relative motion, the carrier Doppler frequency of the received signal more navigation larger range when the Doppler frequency shift beyond a certain range of time, locked loop carrier frequency of the signal can not be more than the top, this time you need an auxiliary module for traction, because the four frequency discriminator ± 250 frequency difference can pull to within a range of ± 10 or so, then the design of the signal carrier large Doppler shift when locked loop frequency discriminator algorithm uses four frequency discriminator, and then after the third-order phase-locked loop to lock-in the results, and finally into the code tracking loop carrier assisted in the case.