Patent ID: 6662107
Filing Date: 2003-12-09
Classification: G01S,G04C,G04F,G04G,G06F,Y02D

Abstract:
A global positioning system (â€œGPSâ€ ) receiver, comprising:a first oscillator configured to provide a clock signal corresponding to GPS time and further configured to be periodically powered down; a second oscillator configured to provide a clock signal corresponding to GPS time, wherein the second oscillator has lower operating lower requirements than the first oscillator, and wherein the second oscillator is configured to operate when the first oscillator is powered down; a ratio counter device coupled to the first oscillator and the second oscillator and configured to determine when edges of the first oscillator clock signal and the second oscillator clock signal are aligned within a negligible window of error, and to determine a ratio between a frequency of the first oscillator and a frequency of the second oscillator during an interval of alignment: and a processor coupled to the ratio counter, the first oscillator and the second oscillator, wherein the processor is configured to direct the GPS receiver to perform acquisition and tracking of GPS satellites using the first oscillator.