A NEW TRACKING TECHNIQUE USING KALMAN FILTER FOR GPS RECEIVER

• Main Authors: Hao-Wei Li, 李浩緯
• Other Authors: Mu-Huo Cheng
• Format: Others
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/67349037473401041165

碩士 === 國立交通大學 === 電機與控制工程系所 === 94 === The goal of signal tracking in GPS receiver is to track the Pseudo-Random Number (PRN) code delay and the Doppler frequency. The tracking methods are performed using early-late method via a closed loop with a loop filter. The PI is commonly used to realize the loop filter; The PI parameters are empirically determined. The tracking performance varies with the choice of PI parameters. This thesis configures the tracking of PRN code delay and Doppler frequency as problems of observer design, such that the extended Kalman filter (EKF) and Kalman filter (KF) algorithm are applied realize the observers. The tracking of PRN code delay which is realized by a digital delay-locked loop is configured as a nonlinear observer problem such that the EKF can be used to estimate the delay, while the tracking of the Doppler frequency realized by a digital phase-locked loop, is configured as a linear observer problem, hence the KF can be used as the observer. This approach not only alleviates the burden of designing PI parameters but also obtain a fast tracking algorithm. Computer simulations are also performed to demonstrate the advantages of our proposed method.