E911 POSITIONING VIA BACKGROUND SIGNAL TRACKING

• US 20170070873A1
• Filed: 09/08/2015
• Published: 03/09/2017
• Est. Priority Date: 09/08/2015
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Pon, Rayman Wai, Farmer, Dominic Gerard
• Granted Patent: US 9,992,653 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 5/0221 Receivers
• CPC Class Codes: G01S 5/02524 Creating or updating the radio-map
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: H04W 4/021 Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]

Abstract

Example methods, apparatuses, or articles of manufacture are disclosed herein that may be utilized, in whole or in part, to facilitate or support one or more operations and/or techniques for improved E911 positioning via background signal tracking, such as for use in or with a mobile communication device, for example.

Claims

1. A method for background signal tracking at a mobile device comprising:

obtaining one or more observations of one or more terrestrial signals;

storing the one or more observations in a local memory;

retrieving, in response to an emergency event, the one or more stored observations for use, at least in part, in acquisition of one or more reference signals; and

determining a position fix of the mobile device based, at least in part, on the one or more stored observations.

2. The method of claim 1, wherein the one or more stored observations comprise at least one of the following:

a measured time of arrival (TOA) of the one or more terrestrial signals;

a measured time difference of arrival (TDOA) of the one or more terrestrial signals;

an identity of a terrestrial transmitter transmitting the one or more terrestrial signals;

or any combination thereof.

4. The method of claim 1, wherein the emergency event is detected via a message indicative of the emergency event and received at the mobile device.

5. The method of claim 1, and further comprising narrowing a search window for the acquisition of the one or more reference signals.

6. The method of claim 5, wherein the narrowing the search window for the acquisition of the one or more reference signals further comprises narrowing the size of a search window of an expected uncertainty parameter provided in a message received at the mobile device and indicative of the emergency event.

7. The method of claim 6, wherein the message received at the mobile device and indicative of the emergency event comprises an LTE positioning protocol message communicated in response to a detection of the emergency event at a Public Safety Answering Point (PSAP).

8. The method of claim 1, and further comprising detecting a true Early Arrival Path (EAP) for the acquisition of the one or more reference signals.

9. The method of claim 1, wherein the one or more terrestrial signals comprise at least one of the following:

one or more positioning reference signals (PRS) in Long Term Evolution (LTE);

one or more cell-specific reference signals (CRS) signals in Long Term Evolution (LTE);

one or more 1×

signals for in Code Division Multiple Access (CDMA);

one or more satellite positioning system (SPS) signals;

one or more wireless wide area network (WWAN) signals;

or any combination thereof.

10. The method of claim 1, wherein the one or more observations are obtained independently from the emergency event.

11. The method of claim 1, and further comprising augmenting the one or more observations with sensor data for use, at least in part, in acquisition of the one or more reference signals.

12. The method of claim 1, wherein the one or more reference signals are acquired via at least one of the following:

an observed time difference of arrival (OTDOA) positioning technique;

an Advanced Forward Link Trilateration (AFLT) positioning technique;

an SPS positioning technique;

or any combination thereof.

13. The method of claim 1, wherein the emergency event comprises a 911 call originating from the mobile device.

14. The method of claim 1, wherein the acquisition of the one or more reference signals comprises at least acquisition of:

one or more measurements of TOA of the one or more reference signals or one or more measurements of TDOA of the one or more reference signals.

15. The method of claim 1, and further comprising filtering one or more measurements of TOA or TDOA of one or more reference signals subsequent to a message indicative of the emergency event.

16. The method of claim 1, wherein the one or more reference signals are acquired in a Global Navigation Satellite Systems (GNSS)-denied environment.

17. The method of claim 1, and further comprising detecting expected multipath for the acquisition of the one or more reference signals.

18. An apparatus for background signal tracking comprising:

means for obtaining one or more observations of one or more terrestrial signals;

means for storing the one or more observations in a local memory;

means for retrieving, in response to an emergency event, the one or more stored observations for use, at least in part, in acquisition of one or more reference signals; and

means for determining a position fix of a mobile device based, at least in part, on the one or more stored observations.

19. The apparatus of claim 18, and further comprising means for narrowing a search window for the acquisition of the one or more reference signals.

20. The apparatus of claim 18, and further comprising means for detecting a true Early Arrival Path (EAP) for the acquisition of the one or more reference signals.

21. An apparatus for background signal tracking comprising:

a wireless transceiver to communicate with an electronic communications network, the wireless transceiver configured to;

obtain one or more observations of one or more terrestrial signals; and

one or more processors coupled to a memory and to the wireless transceiver, the one or more processors configured to;

store the one or more observations in a local memory;

retrieve, in response to an emergency event, the one or more stored observations for use, at least in part, in acquisition of one or more reference signals; and

determine a position fix of a mobile device based, at least in part, on the one or more stored observations.

22. The apparatus of claim 21, wherein the one or more stored observations comprise at least one of the following:

a measured time of arrival (TOA) of the one or more terrestrial signals;

a measured time difference of arrival (TDOA) of the one or more terrestrial signals;

an identity of a terrestrial transmitter transmitting the one or more terrestrial signals;

or any combination thereof.

23. The apparatus of claim 21, wherein the one or more processors further to narrow a search window for the acquisition of the one or more reference signals.

24. The apparatus of claim 21, wherein the one or more processors further to detect a true Early Arrival Path (EAP) for the acquisition of the one or more reference signals.

25. The apparatus of claim 21, wherein the emergency event is detected via a message received at the mobile device.

26. The apparatus of claim 21, wherein the one or more terrestrial signals to comprise at least one of the following:

one or more positioning reference signals (PRS) in Long Term Evolution (LTE);

one or more cell-specific reference signals (CRS) signals in Long Term Evolution (LTE);

one or more 1×

signals for in Code Division Multiple Access (CDMA);

one or more satellite positioning system (SPS) signals;

one or more wireless wide area network (WWAN) signals;

or any combination thereof.

27. The apparatus of claim 21, wherein the one or more reference signals are to be acquired via at least one of the following:

an observed time difference of arrival (OTDOA) positioning technique;

an Advanced Forward Link Trilateration (AFLT) positioning technique;

an SPS positioning technique;

or any combination thereof.

28. The apparatus of claim 21, wherein the one or more observations are to be obtained independently from the emergency event.

29. The apparatus of claim 21, wherein the one or more processors further to filter one or more measurements of TOA or TDOA of one or more reference signals subsequent to the emergency event.

30. A non-transitory storage medium having instructions executable by a processor to:

obtain one or more observations of one or more terrestrial signals;

store the one or more observations in a local memory;

retrieve, in response to an emergency event, the one or more stored observations for use, at least in part, in acquisition of one or more reference signals; and

determine a position fix of a mobile device based, at least in part, on the one or more stored observations.