GNSS receiver using signals of opportunity and assistance information to reduce the time to first fix

A GNSS receiver including:

• a radio frequency front end for receiving GNSS satellite signals and signals of opportunity, which contain random content, the radio frequency front end including one or more configurable front end filters that scan broadcast signals to tune to signals of opportunity;
• an oscillator for use in acquiring and tracking the GNSS satellite signals;
• and
• one or more processors configured to
• select one or more signals of opportunity, process the selected signals of opportunity and phase lock the oscillator to one of the selected signals of opportunity, and
• use a narrowed band to track the GNSS satellite signals.

A system for reducing the time to first fix position, the system including:

• a base GNSS receiver for acquiring and tracking GNSS satellite signals and providing assistance information;
• a remote GNSS receiver with
• a radio frequency front end for receiving GNSS satellite signals and signals of opportunity, which contain random content, the radio frequency front end including one or more configurable front end filters that scan broadcast signals to tune to signals of opportunity;
• a network connection to receive assistance information from the base GNSS receiver;
• an oscillator for use in acquiring and tracking the GNSS signals;
• and
• one or more processors configured to
• select one or more signals of opportunity, process the selected signals of opportunity and estimate a frequency offset for the oscillator based on a difference between the frequencies of one or more of the selected signals of opportunity as determined by the front end and broadcast frequencies of the one or more signals of opportunity, and
• use the estimated oscillator frequency offset to reduce a search window for acquiring the GNSS satellite signals.