Crystal oscillator calibration

A method of temperature-calibrating an uncompensated crystal oscillator (XO) in a mobile device during mobile device operation, the method comprising:

• receiving a first set of wireless signals comprising at least a first wireless signal, from a signal source of known frequency and known Doppler, at a first temperature, wherein a plurality of satellite signals is unavailable;
• estimating a first frequency of the XO at the first temperature, based on at least the first wireless signal;
• and
• temperature-calibrating the XO based on the first frequency and the first temperature.

A system comprising:

• a mobile device comprising an uncompensated crystal oscillator (XO);
• means for receiving a first set of wireless signals comprising at least a first wireless signal of known frequency, at a first temperature;
• means for estimating a first frequency of the XO at the first temperature, based on at least the first wireless signal;
• and
• means for temperature-calibrating the XO based on the first frequency and the first temperature during operation of the mobile device.

A system comprising:

• a mobile device comprising an uncompensated crystal oscillator (XO);
• means for receiving a first set of wireless signals comprising at least a first wireless signal, from a signal source of known frequency and known Doppler, at a first temperature, wherein a plurality of satellite signals is unavailable;
• means for estimating a first frequency of the XO at the first temperature, based on at least the first wireless signal;
• and
• means for temperature-calibrating the XO based on the first frequency and the first temperature during operation of the mobile device.

A mobile device comprising:

• an uncompensated crystal oscillator (XO);
• a temperature sensor configured to provide a first temperature;
• one or more receivers configured to receive a first set of wireless signals comprising at least a first wireless signal of known frequency, at the first temperature;
• and
• a processor configured to estimate a first frequency of the XO at the first temperature, based on at least the first wireless signal, and temperature-calibrate the XO based on the first frequency and the first temperature during operation of the mobile device.

A mobile device comprising:

• an uncompensated crystal oscillator (XO);
• a temperature configured to provide a first temperature;
• one or more receivers configured to receive a first set of wireless signals comprising at least a first wireless signal, from a signal source of known frequency and known Doppler, at the first temperature, wherein a plurality of satellite signals is unavailable;
• and
• a processor configured to estimate a first frequency of the XO at the first temperature, based on at least the first wireless signal and temperature-calibrate the XO based on the first frequency and the first temperature.

A mobile device comprising:

• an uncompensated crystal oscillator (XO);
• a temperature sensor configured to provide a first temperature;
• one or more receivers configured to receive a first set of wireless signals comprising at least a first wireless signal of known frequency, at a first temperature;
• a processor;
• and
• a non-transitory computer-readable storage medium comprising code, which, when executed by the processor, causes the processor to perform operations for temperature-calibrating a crystal oscillator (XO), the non-transitory computer-readable storage medium comprising:
• code for estimating a first frequency of the XO at the first temperature, based on at least the first wireless signal;
• code for determining unknown coefficients of a polynomial equation comprising a relationship between frequency of the XO and temperature based on at least the first frequency and the first temperature.