Positioning with wireless local area networks and WLAN-aided global positioning systems

• US 10,212,540 B2
• Filed: 08/21/2017
• Issued: 02/19/2019
• Est. Priority Date: 02/14/2003
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wang, Yi-Hsiu
• Primary Examiner(s): Le, Danh C
• Application Number:
  US15/682,415
• Publication Number:
  US 20170374501A1
• Time in Patent Office: 547 Days
• Field of Search: 4554566, 4554561, 4555521, 4555501, 34235771, 370338
• CPC Class Codes: G01S 19/05 providing aiding data
• 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 19/252 Employing an initial estimate of location in generating assistance data
• CPC Class Codes: G01S 19/28 Satellite selection
• CPC Class Codes: G01S 19/29 carrier including Doppler, related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/48 by combining or switching between position solutions derived from the satellite radio beacon positioning system and position solutions derived from a further system
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04B 7/1851 Systems using a satellite or space-based relay H04B7/18508, H04B7/18521 take precedence; providing specific services H04B7/18523 - H04B7/18576
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Accurate position capability can be quickly provided using a Wireless Local Area Network (WLAN). When associated with a WLAN, a wireless device can quickly determine its relative and/or coordinate position based on information provided by an access point in the WLAN. Before a wireless device disassociates with the access point, the WLAN can periodically provide time, location, and decoded GPS data to the wireless device. In this manner, the wireless device can significantly reduce the time to acquire the necessary GPS satellite data (i.e. on the order if seconds instead of minutes) to determine its coordinate position.

Claims

1. A wireless device comprising:

a wireless local area network (WLAN) baseband configured to;

receive decoded global positioning system (GPS) data from one or more access points in a communication system;

a GPS baseband configured to;

identify a first GPS satellite based at least in part on the decoded GPS data;

acquire a GPS signal from the first GPS satellite; and

determine frequency offsets for other GPS satellites based at least in part on the acquired GPS signal; and

wherein the GPS baseband comprises;

a plurality of correlators configured to operate in parallel to acquire the GPS signal from the first GPS satellite, wherein each pair of correlators includes an in-phase correlator and a quadrature correlator.

2. The wireless device of claim 1, wherein the GPS baseband is further configured to determine time offsets for the other GPS satellites based at least in part on the acquired GPS signal.

3. The wireless device of claim 1, wherein the GPS baseband is further configured to identify the first GPS satellite based on an elevation angle between the wireless device and the first GPS satellite.

4. The wireless device of claim 3, wherein the elevation angle is determined based at least in part the decoded GPS data.

5. The wireless device of claim 3, wherein the GPS baseband is further configured to approximate a Doppler effect on the GPS signal from the first GPS satellite to be zero hertz, wherein the Doppler effect based on the elevation angle.

6. The wireless device of claim 1, wherein the GPS baseband is further configured to identify the first GPS satellite based on ephemeris data included in the decoded GPS data.

7. The wireless device of claim 1, wherein the plurality of correlators is partitioned into tracking sets configured to track a plurality of GPS satellites after acquiring the GPS signal from the first GPS satellite.

8. The wireless device of claim 1, wherein the GPS baseband is further configured to determine a frequency offset associated with the GPS signal based on a frequency difference between an oscillator frequency of the first GPS satellite and a receiver frequency of the wireless device.

9. The wireless device of claim 8, wherein the GPS baseband is further configured to:

acquire GPS signals from GPS satellites based at least in part on the determined frequency offset and ephemeris data included in the decoded GPS data; and

determine a location of the wireless device based at least in part on the acquired GPS signals.

10. A method comprising:

receiving, by a wireless local area network (WLAN) baseband of a wireless device, decoded global positioning system (GPS) data from one or more access points in a communication system;

identifying, by a GPS baseband of the wireless device, a first GPS satellite based at least in part on the decoded GPS data;

acquiring a GPS signal from the first GPS satellite, by a plurality of correlators operating in parallel, wherein each pair of correlators includes an in-phase correlator and a quadrature correlator; and

determining frequency offsets for other GPS satellites based at least in part on the acquired GPS signal.

11. The method of claim 10, further comprising determining time offsets for the other GPS satellites based at least in part on the acquired GPS signal.

12. The method of claim 11, wherein the first GPS satellite is identified based on an elevation angle between the wireless device and the first GPS satellite.

13. The method of claim 12, wherein the elevation angle is determined based at least in part on the decoded GPS data.

14. The method of claim 12, further comprising:

approximating a Doppler effect on the GPS signal from the first GPS satellite to be zero hertz, wherein the Doppler effect is based on the elevation angle.

15. The method of claim 10, wherein the first GPS satellite is identified based on ephemeris data included in the decoded GPS data.

16. The method of claim 10, further comprising:

determining a frequency offset associated with the GPS signal based on a frequency difference between an oscillator frequency of the first GPS satellite and a receiver frequency of the wireless device.

17. The method of claim 16, further comprising:

acquiring GPS signals from GPS satellites based at least in part on the determined frequency offset and ephemeris data included in the decoded GPS data; and

determine a location of the wireless device based at least in part on the acquired GPS signals.

18. A wireless device comprising:

a wireless local area network (WLAN) baseband configured to;

receive decoded global positioning system (GPS) data from one or more access points in a communication system; and

a GPS baseband configured to;

identify a first GPS satellite based at least in part on the decoded GPS data;

acquire a GPS signal from the first GPS satellite, by a plurality of correlators operating in parallel, wherein each pair of correlators includes an in-phase correlator and a quadrature correlator;

determine a frequency offset associated with the GPS signal from the first GPS satellite; and

determine a location of the wireless device based at least in part on the determined frequency offset.

19. The wireless device of claim 18, wherein the GPS baseband is further configured to:

acquire GPS signals from GPS satellites based at least in part on the determined frequency offset, wherein the location of the wireless device is determined based at least in part on the acquired GPS signals from the GPS satellites.