DETERMINATION OF DIFFERENTIAL FORWARD LINK CALIBRATION IN LTE NETWORKS FOR POSITIONING

• US 20140295881A1
• Filed: 01/02/2014
• Published: 10/02/2014
• Est. Priority Date: 02/07/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gao, Weihua, Opshaug, Guttorm R., Marshall, Grant Alexander, Ristic, Borislav, Werner, Benjamin
• Granted Patent: US 9,549,288 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0236 Assistance data, e.g. base station almanac
• 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 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds

Abstract

Techniques are provided which may be implemented using various methods and/or apparatuses to determine time difference of arrival of signals from two base stations as received at a mobile device, to use the time difference of arrival to determine differential forward link calibration for at least two base stations, and also to determine location using the differential forward link calibration for at least two base stations, determined using the time difference of arrival of signals from at least two base stations as received by a mobile device.

Claims

1. A method of providing measurements from a mobile device to a location server, comprising:

determining an estimated location of the mobile device;

receiving a first reference signal from a first base station;

receiving a second reference signal from a second base station;

determining a difference between times of arrival of the first reference signal and the second reference signal; and

transmitting, from the mobile device, one or more messages comprising the estimated location of the mobile device and the determined difference between times of arrival to the location server.

2. The method of claim 1, wherein said method is initiated in response to receipt of a message from the location server requesting the estimated location of the mobile device and for the determined difference between times of arrival.

3. The method of claim 1, wherein said method is initiated in response to receipt of a user input selection at the mobile device.

4. The method of claim 1, wherein determining said estimated location further comprises:

requesting positioning assistance data from the location server;

receiving positioning assistance data from the location server; and

applying said received positioning assistance data to one or more measurements to compute said estimated location.

5. The method of claim 1, further comprising:

receiving from said location server a request for measurements for the mobile device from said location server; and

receiving positioning assistance data descriptive of aspects of at least two base stations from the location server.

6. The method of claim 5, wherein said positioning assistance data comprises estimated locations of the at least two base stations, and wherein determining the estimated location of the mobile device comprises application of said estimated locations of the at least two base stations to computation of said estimated location of the mobile device.

7. The method of claim 1, wherein the first reference signal comprises one of a first positioning reference signal or a first carrier reference signal, and wherein the second reference signal comprises a second positioning reference signal or a second carrier reference signal.

8. A mobile device comprising:

a transceiver to transmit messages to and receive messages from a communication network; and

one or more processors to;

determine an estimated location of the mobile device;

measure a time of arrival of a first reference signal acquired at said transceiver from a first base station;

measure a time of arrival of a second reference signal acquired at said transceiver from a second base station;

determine a difference between times of arrival of the first reference signal and the second reference signal based, at least in part, on the measured time of arrival of the first reference signal and measured time of arrival of the second reference signal; and

initiate transmission of one or more messages through said transceiver comprising the estimated location of the mobile device and the determined difference between times of arrival to a location server.

9. The mobile device of claim 8, wherein the one or more processors are further to:

obtain from said location server a request for measurements for the mobile device from the location server; and

obtain positioning assistance data descriptive of aspects of at least two base stations from the location server.

10. The mobile device of claim 9, wherein said positioning assistance data comprises estimated locations of the at least two base stations, and wherein determining the estimated location of the mobile device comprises application of said estimated locations of the at least two base stations to computation of said estimated location of the mobile device.

11. The mobile device of claim 8, wherein the first reference signal comprises one of a first positioning reference signal or a first carrier reference signal, and wherein the second reference signal comprises a second positioning reference signal or a second carrier reference signal.

12. An article comprising:

a non-transitory storage medium comprising machine-readable instructions stored thereon which are executable on a mobile device to;

determine an estimated location of the mobile device;

determine a time of arrival of a first reference signal acquired at said mobile device from a first base station;

determine a time of arrival of a second reference signal acquired at said mobile device from a second base station;

determine a difference between times of arrival of the first reference signal and the second reference signal based, at least in part, on the determined time of arrival of the first reference signal and determined time of arrival of the second reference signal; and

initiate transmission of one or more messages through a communication network to a location server comprising the estimated location of the mobile device and the determined difference between times of arrival.

13. The article of claim 12, wherein said instructions are further executable to:

obtain from said location server a request for measurements for the mobile device from the location server; and

obtain positioning assistance data descriptive of aspects of at least two base stations from the location server.

14. The article of claim 12, wherein said positioning assistance data comprises estimated locations of the first and second base stations, and wherein determining the estimated location of the mobile device comprises application of said estimated locations of the first and second base stations to computation of said estimated location of the mobile device.

15. The article of claim 12, wherein the first reference signal comprises one of a first positioning reference signal or a first carrier reference signal, and wherein the second reference signal comprises a second positioning reference signal or a second carrier reference signal.

16. An apparatus at a mobile device, comprising:

means for determining an estimated location of the mobile device;

means for receiving a first reference signal from a first base station;

means for receiving a second reference signal from a second base station;

means for determining a difference between times of arrival of the first reference signal and the second reference signal; and

means for transmitting, from the mobile device, one or more messages comprising the estimated location of the mobile device and the determined difference between times of arrival to a location server.

17. The apparatus of claim 16, wherein said apparatus is initiated in response to receipt of a message from the location server requesting the estimated location of the mobile device and for the determined difference between times of arrival.

18. The apparatus of claim 16, wherein said apparatus is initiated in response to receipt of a user input selection at the mobile device.

19. The apparatus of claim 16, wherein said means for determining said estimated location further comprises:

means for requesting positioning assistance data from the location server;

means for receiving positioning assistance data from the location server; and

means for applying said received positioning assistance data to one or more measurements to compute said estimated location.

20. The apparatus of claim 16, further comprising:

means for receiving from said location server a request for measurements for the mobile device from the location server; and

means for receiving positioning assistance data descriptive of aspects of at least two base stations from the location server.

21. The apparatus of claim 20, wherein said positioning assistance data comprises estimated locations of the first and second base stations, and wherein determining the estimated location of the mobile device comprises application of said estimated locations of the first and second base stations to computation of said estimated location of the mobile device.

22. The apparatus of claim 16, wherein the first reference signal comprises one of a first positioning reference signal or a first carrier reference signal, and wherein the second reference signal comprises a second positioning reference signal or a second carrier reference signal.