×

Reference oscillator management for wireless devices having position determination functionality

  • US 9,103,915 B2
  • Filed: 07/01/2013
  • Issued: 08/11/2015
  • Est. Priority Date: 06/18/2008
  • Status: Active Grant
First Claim
Patent Images

1. A method for managing a reference oscillator within a wireless device, comprising:

  • selecting reference oscillator parameters associated with a lowest reference oscillator error, wherein the selection is based upon reference oscillator parameters derived using different technologies within the wireless device, wherein the reference oscillator comprises a tunable reference oscillator, and wherein the reference oscillator parameters include tunable reference oscillator parameters, a reference oscillator frequency control value, a reference oscillator frequency bias, a reference oscillator frequency bias uncertainty and a time at which the reference oscillator parameters were determined;

    acquiring a satellite based upon the selected reference oscillator parameters;

    calculating a satellite-based position fix;

    determining a quality of the satellite-based position fix, wherein the quality corresponds to an uncertainty associated with the selected reference oscillator parameters;

    updating the reference oscillator parameters based upon the quality of the satellite-based position fix;

    determining, as the tunable reference oscillator parameters, a frequency center and a width of a search window using the reference oscillator parameters;

    tuning the tunable reference oscillator using the determined tunable reference oscillator parameters;

    determining the reference oscillator parameters based upon the quality of the satellite-based position fix;

    storing the reference oscillator parameters when the wireless device successfully determines the satellite-based position fix;

    receiving a current reference oscillator frequency control value and a current reference oscillator frequency bias estimate;

    adjusting the received reference oscillator frequency bias estimate;

    performing sanity checks on the adjusted reference oscillator frequency bias estimate;

    determining reference oscillator parameters for storage based upon the adjusted reference oscillator frequency bias estimate; and

    incrementing a counter which represents a confidence in the determined reference oscillator parameters.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×