Design of a General Single Frequency GPS Receiver Research Platform for High Dynamic and Weak Signal

Abstract

This paper demonstrates a GPS receiver research platform. It can generate digital Immediate Frequency (IF) GPS signal and some signal synchronize functions on high dynamic and weak signal environment. It is based on a mathematical signal model which expresses the digitized IF GPS signal as a function of various errors during propagation. The simulator is able to simulate more than 12 GPS satellite signals due to user. In order to validate the signals and develop more effective algorithm for various GPS signals and different tracking techniques are discussed. Performances of different type tracking loops outputs on particular environment are demonstrated and analyzed. Especially, for weak signal environment, aiming at tracking degraded signal, an errors tracking scheme based on modified Unscented Kalman Filtering (UKF) is designed and implemented. The 30dB/Hz weak signal test result validated the tracking scheme.