Abstract: A global positioning system (GPS) receiver and a method having a fast time to first fix (TTFF) using GPS signal Doppler frequency shifts for correcting the local clock time and using information for an expected GPS message for synchronizing the corrected local clock time to GPS time. The GPS receiver includes radio frequency (RF) circuitry for receiving and downconverting a spread spectrum GPS satellite signal, a correlator for despreading the downconverted GPS signal and providing a GPS bit stream, a clock for providing a local time, and a processor including an executable code.

Abstract: A global positioning system (GPS) receiver apparatus using time and frequency information derived from a radio signal other than the GPS satellite signal for improving the time to first fix (TTFF). The GPS receiver apparatus includes a GPS signal receiver for receiving a GPS satellite signal modulated with data bits and a radio signal receiver for receiving a radio signal having a standard time and/or a standard frequency. The radio signal receiver provides standard time information to the GPS signal receiver. The GPS signal receiver uses the standard time information to resolve a GPS time for a time of arrival of a data bit. The GPS signal receiver includes a propagation delay calibrator for correcting the standard time for the travel time due to the path length for the radio signal. The radio signal receiver uses a reference clock signal provided by the GPS signal receiver for determining a frequency error between a frequency of the reference clock signal and the standard frequency.