PERFORMANCE ANALYSIS OF GPS CARRIER PHASE OBSERVABLE

The accuracy analysis of Global Positioning System (GPS) carrier phase observable measured by a digital GPS receiver is presented A digital phase-locked loop (DPLL) is modeled to extract the carrier phase of th e received signal after a pseudorandom noise (PRN) code synchronizatio n system despreads the received PRN coded signal Based on phase noise characteristics of the Input signal the following performance of the f irst, second, and third order DPLLs is analyzed mathematically 1) loop stability and transient process; 2) steady-state probability density function (pdf), mean and variance of phase tracking error; 3) carrier phase acquisition performance; and 4) mean time to the first cycle-sli pping. The theoretical analysis is verified by Monte Carlo computer si mulations. The analysis of the dependency of the phase observable erro r on system dynamics, input noise and receiver design parameters provi des with an important reference in designing the carrier phase synchro nization system for high accuracy GPS positioning.