Low power positioning techniques for mobile devices

Patent metadata

Field	Value
Publication number	US-9733361-B2
Application number	US-201414480396-A
Country	US
Kind code	B2
Filing date	Sep 8, 2014
Priority date	Nov 6, 2013
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

Techniques for managing power consumption of a Global Navigation Satellite System (GNSS) receiver of a mobile device are provided. These techniques include a method that includes deriving a GNSS search window for the GNSS receiver based on a position uncertainty (PUNC) and a time uncertainty (TUNC), selecting a GNSS search mode based on the GNSS search window and resources available for searching for signals from GNSS satellite vehicles (SVs), wherein an estimated power consumption associated with execution of a GNSS search associated with the GNSS search mode does not exceed a power consumption limit specified for the GNSS receiver conducting the GNSS search using the GNSS search mode, and estimating a position of the mobile device.

First claim

What is claimed is:

1. A method for managing power consumption of a Global Navigation Satellite System (GNSS) receiver of a mobile device, the method comprising:
deriving a GNSS search window for the GNSS receiver based on a position uncertainty (PUNC) and a time uncertainty (TUNC), the PUNC being determined at least in part by sensor data indicating whether the mobile device is stationary or has moved less than a predetermined threshold distance from a last known position;
selecting a GNSS search mode based on the GNSS search window and resources available for searching for signals from GNSS satellite vehicles (SVs), wherein an estimated power consumption associated with execution of a GNSS search associated with the GNSS search mode does not exceed a power consumption limit specified for the GNSS receiver;
conducting the GNSS search using the GNSS search mode; and
estimating a position of the mobile device based at least in part on results of the GNSS search.

2. The method of claim 1 , further comprising:
determining the PUNC associated with the position of the mobile device, wherein determining the PUNC associated with the position of the mobile device comprises determining a coarse position of the mobile device using multiple position determination techniques and selecting a coarse position having a smallest PUNC, and
wherein selecting the GNSS search mode based on the GNSS search window and the resources available for searching for signals from SVs comprises selecting the GNSS search mode at least in part based on the PUNC.

3. The method of claim 1 , wherein estimating the position of the mobile device comprises estimating the position of the mobile device based at least in part on results of the GNSS search.

4. The method of claim 1 , wherein the power consumption limit specified for the GNSS receiver comprises an average power consumption limit over a predetermined period of time.

5. The method of claim 1 , wherein selecting the GNSS search mode comprises selecting the GNSS search mode from a low uncertainty mode and a high uncertainty mode, the low uncertainty mode being associated a smaller search window and a higher duty cycle, the high uncertainty mode being associated with a larger search window and a lower duty cycle.

6. The method of claim 5 wherein selecting the GNSS search mode from the low uncertainty mode and the high uncertainty mode based on the GNSS search window and the resources available for searching for signals from GNSS SVs comprises selecting the low uncertainty mode based on the sensor data indicating that the mobile device is stationary or has moved less than a predetermined threshold distance from a last known position.

7. The method of claim 5 , wherein selecting the GNSS search mode from the low uncertainty mode and the high uncertainty mode based on the GNSS search window and the resources available for searching for signals from GNSS SVs comprises:
selecting the low uncertainty mode as the GNSS search mode responsive to the estimated power consumption required to support the GNSS search window being less than or equal to the resources available for concurrently searching for signals from GNSS SVs; and
selecting the high uncertainty mode as the GNSS search mode responsive to the estimated power consumption required to support the GNSS search window being greater than the resources available for concurrently searching for signals from GNSS SVs.

8. The method of claim 7 , further comprising:
estimating the position of the mobile device without using results of the GNSS search responsive to the estimated power consumption required to support the GNSS search window at the GNSS receiver exceeding the resources available for concurrently searching for signals from GNSS SVs by a predetermined threshold.

9. The method of claim 1 , wherein estimating the position of the mobile device using results of the GNSS search further comprises:
obtaining additional position estimate information from at least one additional source of position related information other than the GNSS receiver; and
estimating the position of the mobile device using the results of the GNSS search and the additional position estimate information.

10. The method of claim 9 , wherein the additional position estimate information comprises at least one of signal information from at least one terrestrial wireless transceivers proximate to the mobile device and signal information from at least one motion sensor associated with the mobile device.

11. The method of claim 1 , wherein the power consumption limit specified for the GNSS receiver is received from an application running on the mobile device.

12. The method of claim 11 , wherein the application running on the mobile device is configured to receive an input from a user of the mobile device and to set the power consumption limit based on the input from the user of the mobile device.

13. The method of claim 1 , wherein the power consumption limit specified for the GNSS receiver is determined based on an accuracy requirement of at least one application running on the mobile device.

14. The method of claim 1 , wherein the power consumption limit specified for the GNSS receiver is determined based at least in part on whether the mobile device is receiving power from an external power source or from a battery associated with the mobile device.

15. The method of claim 1 , wherein the power consumption limit specified for the GNSS receiver can be specified as a hard limit or a soft limit, the method further comprising operating the GNSS receiver in a low power state in which the GNSS search is not conducted responsive to determining that the GNSS search would exceed the hard limit.

16. The method of claim 1 , wherein the power consumption limit is associated with a power budget for the GNSS receiver, and selecting the GNSS search mode comprises selecting a GNSS search mode associated with an estimated power consumption that exceeds the power consumption limit specified for the GNSS receiver but does not exceed the power budget for the GNSS receiver.

17. An apparatus for managing power consumption of a Global Navigation Satellite System (GNSS) receiver of a mobile device, the apparatus comprising:
means for deriving a GNSS search window for the GNSS receiver based on a position uncertainty (PUNC) and a time uncertainty (TUNC), the PUNC being determined at least in part by sensor data indicating whether the mobile device is stationary or has moved less than a predetermined threshold distance from a last known position;
means for selecting a GNSS search mode based on the GNSS search window and resources available for searching for signals from GNSS satellite vehicles (SVs), wherein an estimated power consumption associated with execution of a GNSS search associated with the GNSS search mode does not exceed a power consumption limit specified for the GNSS receiver;
means for conducting the GNSS search using the GNSS search mode; and
means for estimating a position of the mobile device using results of the GNSS search.

18. The apparatus of claim 17 , wherein the means for selecting the GNSS search mode comprises means for selecting the GNSS search mode from a low uncertainty mode and a high uncertainty mode, the low uncertainty mode being associated a smaller search window and a higher duty cycle, the high uncertainty mode being associated with a larger search window and a lower duty cycle.

19. The apparatus of claim 18 , wherein the means for selecting the GNSS search mode from the low uncertainty

Assignees

• Qualcomm Inc

Inventors

• Farmer Dominic Gerard
• Morrison William James
• Wu Jie
• Rao Krishnaranjan
• Lin Tong

Classifications

• G01S19/34 Primary

  Power consumption · CPC title

• G01S19/06

  employing an initial estimate of the location of the receiver as aiding data or in generating aiding data · CPC title

• G01S19/24

  Acquisition or tracking {or demodulation} of signals transmitted by the system {(synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073)} · CPC title