Calibration and correction system for satellite position location systems

A method of correcting a GPS receiver in a mobile device using a cellular network signal having a predefined precision carrier frequency, to receive a GPS signal transmitted at a predefined GPS frequency, comprising:

• generating a first frequency signal responsive to said precision carrier frequency;
• generating a second frequency signal in said GPS receiver, to process said GPS signal;
• computing an error between said first and second frequencies in a first time period;
• repeating said error computing at least once during at least a second respective time period to provide a set of error estimations;
• providing an error function of said second frequency directly from said set of error computations;
• predicting an error in a next time period following said repeating utilizing said error function;
• and
• correcting said second frequency to process said GPS signal in said next time.

A method of correcting a GPS receiver in a mobile device to receive a GPS signal transmitted at a predefined GPS frequency using a communication signal transmitted from a cellular base station, said communication signal including a predefined precision carrier frequency, comprising:

• synchronizing a first local oscillator to the precision carrier frequency to generate a first frequency;
• generating a second frequency signal in said GPS receiver having a nominal value close to a predetermined value, said second frequency signal applied to process said GPS signal;
• monitoring said first and second frequencies over a plurality of time periods to provide a frequency measurement for each of said plurality of time periods;
• computing an error in said first and second frequencies for each monitored time period to provide a set of error estimations;
• providing a frequency error vs. time function for said second frequency by fitting a mathematical function responsive to said set of error estimations;
• predicting an error in a next time period utilizing said function;
• developing a correction signal for said next time period responsive to said predicted error;
• and
• processing said GPS signal responsive to said correction signal.

A multiple function portable device for providing cellular communication using a network of cellular stations that operate at predefined ideal cellular frequencies, and also for providing position location using GPS satellites that transmit GPS signals at a predefined GPS frequency, comprising:

• a cellular communication system including a first local oscillator that generates a first frequency for demodulating communications with said network of cellular stations;
• a GPS system including a second local oscillator that generates a second frequency coupled to process said GPS signals;
• an error prediction and correction system that predicts an error in a next time period according to an error function representing measurements of said first and second frequencies over a plurality of previous time periods, said system also generating a correction signal for said next time period responsive to said predicted error;
• and
• said second local oscillator receiving said correction signal and responsive thereto processes said GPS signal during said next time period.