Systems and methods for managing power consumption of a GNSS receiver
The disclosure describes methods of managing the power consumption of a GNSS receiver by identifying when to activate and deactivate the GNSS receiver, and by managing storage of GNSS location data points. In one embodiment, the GNSS receiver is activated if there is a change in wireless transmissions from stationary sources. In another embodiment, the GNSS receiver is deactivated when the GNSS signal quality is sufficient to calculate a GNSS location. In another embodiment, the GNSS receiver is deactivated for a time period in correlation with a GNSS speed. In yet another embodiment, redundant GNSS location data points are identified and only non-redundant data points are stored. In yet another embodiment, a GNSS device comprises a processor and a GNSS receiver configured to track GNSS signals and calculate a GNSS location. The GNSS receiver deactivates when the average signal quality value meets or exceeds the baseline signal value.
1. A method for deactivating a global navigation satellite system (GNSS) receiver, the method comprising:
tracking a GNSS signal from each of at least four GNSS satellites;
computing an average signal quality value of the tracked GNSS signals; and
when the average signal quality value is greater than or equal to a baseline signal quality value,
calculating a GNSS location, and
deactivating the GNSS receiver.
2. The method of claim 1 further comprising storing the GNSS location in memory when the average signal quality value is greater than or equal to a baseline signal quality value.
3. The method of claim 1 , further comprising:
when the average signal quality value is less than the baseline signal quality value,
continued tracking of the GNSS signals, and
computing an updated average signal quality value of the tracked GNSS signals; and
when the updated average signal quality value is greater than or equal to the baseline signal quality value,
calculating the GNSS location, and
deactivating the GNSS receiver.
4. The method of claim 2 , wherein the signal quality value is a carrier-to-noise (C/No) ratio, and wherein the baseline signal quality value is the minimum C/No ratio required to calculate the GNSS location by the GNSS receiver.
5. The method of claim 4 , wherein computing the average signal quality value comprises:
computing a C/No ratio for each of the tracked GNSS signals; and
computing the average C/No ratio using only the four largest C/No ratios.
6. The method of claim 1 , further comprising
calculating a GNSS speed associated with the GNSS location;
setting a time period in correlation with the GNSS speed; and
wherein the GNSS receiver is deactivated for the time period.
7. The method of claim 6 , further comprising setting the time period as:
a long time period when the GNSS speed indicates the receiver is moving at a high speed,
a medium time period when the GNSS speed indicates the receiver is moving at a medium speed, and
a short time period when the GNSS speed indicates the receiver is moving at a low speed.
8. The method of claim 7 , wherein the long time period is 30 seconds, the medium time period is 20 seconds, the short time period is 10 seconds, the high speed is any speed greater than 70 km/hr, the medium speed is any speed greater than 30 km/hr and less than 70 km/hr, and the low speed is any speed greater than 5 km/hr and less than 30 km/hr.
9. A global navigation satellite system (GNSS) device comprising:
a processor;
a GNSS receiver configured to:
track a GNSS signal from each of at least four GNSS satellites,
compute an average signal quality value of the tracked GNSS signals, and
calculate a GNSS location when the average signal quality value is greater than or equal to a baseline signal quality value; and
a memory coupled to the processor and storing instructions for deactivating the GNSS receiver, wherein the processor is configured to:
deactivate the GNSS receiver when the average signal quality value is greater than or equal to a baseline signal quality value.
10. The GNSS device of claim 9 , wherein the processor is further configured to store the GNSS location in the memory when the average signal quality value is greater than or equal to a baseline signal quality value.
11. The GNSS device of claim 9 , wherein
the GNSS receiver is further configured to:
continue tracking the GNSS signals, and compute an updated average signal quality value of the tracked GNSS signals when the average signal quality value is less than the baseline signal quality value, and
calculate the GNSS location when the updated average signal quality value is greater than or equal to the baseline signal quality value; and
wherein the processor is further configured to deactivate the GNSS receiver when the updated average signal quality value is greater than or equal to the baseline signal quality value.
12. The GNSS device of claim 10 , wherein the signal quality value is a carrier-to-noise (C/No) ratio, and wherein the baseline signal quality value is the minimum C/No ratio required to calculate the GNSS location by the GNSS receiver.
13. The GNSS device of claim 12 , wherein the GNSS receiver is further configured to compute the average signal quality value by:
computing a C/No ratio for each of the tracked GNSS signals; and
computing the average C/No ratio using only the four largest C/No ratios.
14. The GNSS device of claim 9 ,
wherein the GNSS receiver is further configured to calculate a GNSS speed associated with the GNSS location; and
wherein the processor is further configured to set a time period is in correlation with the GNSS speed, and deactivate the GNSS receiver for the time period.
15. The GNSS device of claim 14 , wherein the processor is further configured to set the time period as:
a long time period when the GNSS speed indicates the receiver is moving at a high speed,
a medium time period when the GNSS speed indicates the receiver is moving at a medium speed, and
a short time period when the GNSS speed indicates the receiver is moving at a low speed.
16. The GNSS device of claim 15 , wherein the long time period is 30 seconds, the medium time period is 20 seconds, the short time period is 10 seconds, the high speed is any speed greater than 70 km/hr, the medium speed is any speed greater than 30 km/hr and less than 70 km/hr, and the low speed is any speed greater than 5 km/hr and less than 30 km/hr.
17. The GNSS device of claim 14 ,
wherein the processor is further configured to activate the GNSS receiver after the time period has passed;
wherein the GNSS receiver is further configured to calculate an updated GNSS location and an updated GNSS speed associated with the updated GNSS location; and
wherein the processor is further configured to reset the time period in correlation with the updated GNSS speed.
18. The GNSS device of claim 14 , wherein the GNSS speed indicates that the GNSS device is not in motion, and wherein the GNSS receiver is further configured to
continue tracking the GNSS signals, and
compute an updated location and an updated GNSS speed associated with the updated GNSS location.