GPS receiver using a radio signal for improving time to first fix

A global positioning system (GPS) receiver apparatus, comprising:

• a radio signal receiver for receiving a radio signal having an accurate carrier frequency and for providing frequency error information for a difference between said carrier frequency and a multiple of a frequency of a reference clock signal;
• and
• a GPS signal receiver coupled to the radio signal receiver, including:
• a) a reference oscillator for providing said reference clock signal;
• b) a microcomputer for using said frequency error information for providing a frequency adjustment;
• and
• c) a digital signal processor for using said frequency adjustment for pre-tuning to a frequency for acquiring a GPS signal.

A method for improving time to first fix in a global positioning system (GPS) receiver apparatus for receiving a GPS signal, comprising steps of:

• receiving a radio signal having a standard time;
• decoding said standard time from said radio signal;
• receiving said GPS signal having data bits;
• and
• using said standard time for resolving a GPS-based time for a time of arrival of one of said data bits.

A method for improving time to first fix in a global positioning system (GPS) receiver apparatus for receiving a GPS signal, comprising steps of:

• receiving a radio signal having an accurate carrier frequency;
• providing a reference clock signal;
• determining a frequency error for a difference between said carrier frequency and a multiple of a frequency of said reference clock signal;
• using said frequency error for computing a frequency adjustment;
• and
• using said frequency adjustment in a digital signal processor in said GPS receiver for pre-tuning to a frequency for acquiring said GPS signal.