FAST GPS RECOVERY USING MAP VECTOR DATA

• US 20140062777A1
• Filed: 08/30/2013
• Published: 03/06/2014
• Est. Priority Date: 08/31/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: MacGougan, Glenn D., Mayor, Robert W., Rhee, Stephen J.
• Granted Patent: US 9,798,011 B2
• Time in Patent Office: Days
• US Class Current: 342/357.43
• CPC Class Codes: G01S 19/06 employing an initial estimate of the location of the receiver as aiding data or in generating aiding data
• CPC Class Codes: G01S 19/07 providing data for correcting measured positioning data, e.g. DGPS [differential GPS] or ionosphere corrections
• CPC Class Codes: G01S 19/24 Acquisition or tracking or demodulation of signals transmitted by the system synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073
• CPC Class Codes: G01S 19/26 involving a sensor measurement for aiding acquisition or tracking
• CPC Class Codes: G01S 19/40 Correcting position, velocity or attitude
• CPC Class Codes: G01S 19/42 Determining position

Abstract

Methods and apparatuses to assist a global positioning system (GPS) module to determine GPS position estimates for a wireless communication device is disclosed. Processing circuitry in the wireless communication device determines a potential or an actual inaccuracy in a GPS position estimate obtained from a GPS module. The processing circuitry obtains a set of map vector data stored in or associated with the wireless communication device. The processing circuitry determines a location estimate of the wireless communication device based on at least a portion of the set of map vector data. The processing circuitry provides the location estimate to the GPS module and obtains an updated GPS position estimate from the GPS module, the updated GPS position estimate based at least in part on the location estimate provided to the GPS module.

Claims

1. A method to assist a global positioning system (GPS) module to determine GPS position estimates for a wireless communication device, the method comprising:

determining a potential or an actual inaccuracy in a GPS position estimate obtained from the GPS module;

obtaining a set of map vector data stored in or associated with the wireless communication device;

determining a location estimate of the wireless communication device based on at least a portion of the set of map vector data;

providing the location estimate to the GPS module; and

obtaining an updated GPS position estimate from the GPS module, the updated GPS position estimate based at least in part on the location estimate provided to the GPS module.

2. The method recited in claim 1, further comprising:

obtaining a set of sensor data to supplement the set of map vector data; and

determining the location estimate of the wireless communication device based on at least a portion of the set of sensor data and at least the portion of the set of map vector data.

3. The method recited in claim 1, wherein determining the potential or the actual inaccuracy in the GPS position estimate comprises detecting a loss of GPS satellite signals.

4. The method recited in claim 3, further comprising:

detecting a recovery of at least one GPS satellite signal; and

wherein providing the location estimate to the GPS module occurs after detecting the recovery of the at least one GPS satellite signal.

5. The method recited in claim 1, wherein the set of map vector data includes an exit position for a structural object that obstructs GPS satellite signals.

6. The method recited in claim 1, wherein determining the potential or the actual inaccuracy in the GPS position estimate comprises detecting less than four independent GPS satellite signals.

7. The method recited in claim 1, wherein determining the potential or the actual inaccuracy in the GPS position estimate comprises detecting a particular GPS position estimate obtained from the GPS module does not match within a threshold a triangulated position estimate obtained using signals from cellular radio towers or from wireless local area network access points.

8. The method recited in claim 2, wherein determining the location estimate of the wireless communication device comprises selecting a particular exit location from a plurality of exit locations associated with a structural object that obstructs GPS satellite signals.

9. A wireless communication device, comprising:

a global positioning system (GPS) module configured to receive global navigation satellite system (GNSS) signals and to determine a GPS position of the wireless communication device based at least in part on received GNSS signals; and

processing circuitry coupled to the GPS module, the processing circuitry configured to control the wireless communication device to at least;

obtain a set of map vector data from a storage element in or associated with the wireless communication device;

detect a change in direction of translational motion of the wireless communication device;

determine a change in position of the wireless communication device from a first map feature in the set of map vector data to a second map feature in the set of map vector data;

determine a position estimate of the wireless communication device based on the set of map vector data in response to detection of the change in direction; and

provide the position estimate to the GPS module to assist the GPS module to determine the GPS position of the wireless communication device.

10. The wireless communication device recited in claim 9, wherein the processing circuitry determines the change in position of the wireless communication device from the first map feature to the second map feature by detecting a turn of the wireless communication device from a first road onto a second road that intersects the first road.

11. The wireless communication device recited in claim 9, wherein determine the change in direction of translational motion of the wireless communication device comprises detecting a turn of the wireless communication device based on information provided from one or more sensors in the wireless communication device.

12. The wireless communication device recited in claim 11, wherein the one or more sensors comprise at least one of an accelerometer and a gyroscope.

13. The wireless communication device recited in claim 9, wherein detect the change in direction of translational motion of the wireless communication device comprises detect a reduction in an uncertainty region associated with the position of the wireless communication device below a threshold.

14. The wireless communication device recited in claim 9, further comprising cellular wireless circuitry configured to transmit signals to and receive signals from a cellular wireless network, and wherein determine the change in position of the wireless communication device is based at least in part on signals received from a plurality of cellular radio access network systems of the cellular wireless network.

15. The wireless communication device recited in claim 9, further comprising wireless local area network circuitry configured to transmit signals to and receive signals from a wireless local area network, and wherein determine the change in position of the wireless communication device is based at least in part on signals received from a plurality of access points of the wireless local area network.

16. The wireless communication device recited in claim 9, wherein the first map feature comprises an entrance to a structure that obstructs reception of GPS signals and the second map feature comprises an exit from the structure that obstructs reception of GPS signals.

17. The wireless communication device recited in claim 16, wherein the position estimate corresponds to map vector data for the exit from the structure that obstructs reception of GPS signals.

18. The wireless communication device recited in claim 10, wherein the position estimate corresponds to map vector data associated with an intersection of the first road and the second road.

19. The wireless communication device recited in claim 9, wherein the GPS module is further configured to use the position estimate to initialize an adaptive filter to determine the GPS position of the wireless communication device.

20. A computer program product for providing assistance information to determine location estimates in a wireless communication device, the computer program product comprising at least one non-transitory computer readable storage medium having computer program code stored thereon, the computer program code comprising:

computer program code for determining an inaccuracy in a position estimate obtain from a position determination module;

computer program code for obtaining a set of map vector data stored in or associated with the wireless communication device;

computer program code for determining a location estimate of the wireless communication device based on the set of map vector data; and

computer program code for providing the location estimate to the position determination module.