SYSTEM AND METHOD FOR COOPERATIVE POSITIONING

• US 20120172054A1
• Filed: 12/15/2011
• Published: 07/05/2012
• Est. Priority Date: 01/05/2011
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: WATERS, Deric W., PANDE, Tarkesh, BALAKRISHNAN, Jaiganesh
• Application Number:
  US13/327,052
• Publication Number:
  US 20120172054A1
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Apparatus and method for cooperatively positioning a mobile wireless device. In one embodiment a mobile wireless device includes a navigation satellite receiver, a WLAN transceiver, and a cooperative positioning system. The navigation satellite receiver is configured to receive positioning signals from positioning satellites. The cooperative positioning system is configured to receive positioning measurements from a cooperating mobile wireless device via the WLAN transceiver. The received positioning measurements are derived from satellite positioning signals received by the cooperating mobile wireless device. The cooperative positioning system is also configured to determine a position of the mobile wireless device based on the positioning measurements received from the cooperating mobile wireless device, positioning measurements provided by the navigation satellite receiver, and a focal measurement that is a function of at least one of the position and the clock bias of both the mobile wireless device and the cooperating mobile wireless device.

Claims

1. A mobile wireless device, comprising:

a navigation satellite receiver configured to receive positioning signals from positioning satellites;

a wireless local area network (WLAN) transceiver; and

a cooperative positioning system configured to;

receive positioning measurements from a cooperating mobile wireless device via the WLAN transceiver, the received positioning measurements derived from satellite positioning signals received by the cooperating mobile wireless device;

determine a position of the mobile wireless device based on the positioning measurements received from the cooperating mobile wireless device, positioning measurements provided by the navigation satellite receiver, and a focal measurement that is a function of at least one of the position and the clock bias of both the mobile wireless device and the cooperating mobile wireless device.

2. The mobile wireless device of claim 1, wherein the focal measurement comprises at least one of:

distance between the mobile wireless device and the cooperating mobile wireless device;

relative clock bias between the mobile wireless device and the cooperating mobile wireless device;

relative bearing between the mobile wireless device and the cooperating mobile wireless device; and

relative altitude between the mobile wireless device and the cooperating mobile wireless device.

3. The mobile wireless device of claim 1, wherein the cooperative positioning system comprises a Kalman filter configured to iteratively estimate the position of the mobile wireless device.

4. The mobile wireless device of claim 1, wherein the cooperative positioning system is configured to determine the position of the mobile wireless device based on a system of equations comprising:

5. The mobile wireless device of claim 1, wherein the cooperative positioning system comprises a 5-state weighted least squares estimator configured to provide an initial estimate of the location of the mobile wireless device.

6. The mobile wireless device of claim 1, wherein the cooperative positioning system is configured to transmit a message soliciting positioning measurements from the cooperating mobile wireless device in a vendor specific field of at least one of a location configuration request frame, a probe request, and a beacon frame.

7. The mobile wireless device of claim 6, wherein the vendor specific field comprises satellite pseudorange measurements, satellite pseudorange rate measurements, and satellite identification for each measurement.

8. The mobile wireless device of claim 1, wherein one of the mobile wireless device and the cooperating mobile wireless device operate as a soft access point.

9. A method, comprising:

receiving, by a first mobile wireless device, positioning signals transmitted by positioning satellites;

deriving, by the first mobile wireless device, positioning measurements from the positioning signals;

receiving, by the first mobile wireless device, positioning measurements from a second mobile wireless device via a wireless local area network;

determining, by the first mobile wireless device, a position of the first mobile wireless device based on the positioning measurements from the second mobile wireless device, the positioning measurements derived by the first mobile wireless device, and a focal measurement that is a function of at least one of the position and the clock bias of both the first mobile wireless device and the second mobile wireless device.

10. The method of claim 9, further comprising computing the focal measurement as at least one of:

distance between the first mobile wireless device and the second mobile wireless device;

relative clock bias between the first mobile wireless device and the second mobile wireless device;

relative bearing between the first mobile wireless device and the second mobile wireless device; and

relative altitude between the first mobile wireless device and the second mobile wireless device.

11. The method of claim 9, wherein the determining further comprises executing a Kalman filter that iteratively estimates the position of the first mobile wireless device.

12. The method of claim 9, wherein the determining further comprises estimating the position based on a system of equations comprising:

13. The method of claim 9, wherein the determining further comprises establishing an initial value for the position of the first mobile wireless device based on a 5-state weighted least squares estimate.

14. The method of claim 9, further comprising transmitting a message soliciting positioning measurements from the second mobile wireless device in a vendor specific field of at least one of a location configuration request frame, a probe request, and a beacon frame.

15. The method of claim 14, wherein the vendor specific field comprises satellite pseudorange measurements, satellite pseudorange rate measurements, and satellite identification for each measurement.

16. The method of claim 9, further comprising configuring at least on of the first mobile wireless device and the second mobile wireless device to operate as a soft access point on the wireless local area network.

17. A wireless device positioning system, comprising:

a processor configured to;

receive satellite positioning measurements from a host wireless device that includes the processor;

receive satellite positioning measurements from a cooperating wireless device;

determine a position of the host wireless device based on the positioning measurements from the cooperating mobile wireless device, the positioning measurements from the host wireless device, and a focal measurement that is a function of at least one of the position and the clock bias of both the host wireless device and the cooperating mobile wireless device.

18. The wireless device positioning system of claim 17, wherein the focal measurement comprises at least one of:

distance between the host wireless device and the cooperating mobile wireless device;

relative clock bias between the host wireless device and the cooperating mobile wireless device;

relative bearing between the host wireless device and the cooperating mobile wireless device; and

relative altitude between the host wireless device and the cooperating mobile wireless device.

19. The wireless device positioning system of claim 17, wherein the processor is further configured to execute a Kalman filter that iteratively estimates the position of the host wireless device.

20. The wireless device positioning system of claim 17, wherein the processor is further configured to determine the position of the host wireless device based on a system of equations comprising:

21. The wireless device positioning system of claim 17, wherein the processor is further configured to establishing an initial value for the position of the host wireless device based on a 5-state weighted least squares estimate.

22. The wireless device positioning system of claim 17, wherein the processor is further configured to transmit a message soliciting positioning measurements from the cooperating mobile wireless device in a vendor specific field of at least one of a location configuration request frame, a probe request, and a beacon frame.

23. The wireless device positioning system of claim 22, wherein the wherein the vendor specific field comprises satellite pseudorange measurements, satellite pseudorange rate measurements, and satellite identification for each measurement.