SYSTEM AND METHOD TO OBTAIN SIGNAL ACQUISITION ASSISTANCE DATA

• US 20120038510A1
• Filed: 08/19/2011
• Published: 02/16/2012
• Est. Priority Date: 04/25/2003
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gaal, Peter, Sheynblat, Leonid, Patrick, Christopher J., Riley, Wyatt Thomas
• Granted Patent: US 8,711,036 B2
• Time in Patent Office: Days
• US Class Current: 342/357.42
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/254 relating to Doppler shift of satellite signals
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: G01S 19/27 creating, predicting or correcting ephemeris or almanac data within the receiver

Abstract

Signal acquisition assistance data is obtained for receiving devices such as wireless position assisted location devices seeking signals from any source, such as satellite vehicles and base stations. The data may be obtained from previously acquired data, based upon evaluation of changes in parameters such as time and location that may jeopardize validity. In some cases the data may be adjusted for the changes in parameters. Refined data may be calculated by a receiver using partial measurements of signal sets, particularly if the acquisition assistance data provided by a remote entity includes more distinct parameters than have typically been provided. New data need not be obtained until the validity of previous data expires due to limitations upon temporal extrapolation using Doppler coefficients, unless mobile station movement that cannot be compensated is detected, and jeopardizes validity of the previous data.

Claims

1. A method of acquiring a signal at a telecommunications system receiver with the aid of acquisition assistance data, the method comprising:

obtaining acquisition assistance data from an entity remote from the receiver;

determining to acquire a plurality of signals at the receiver;

acquiring a first of the plurality of signals at the receiver;

employing measured parameters of the first of the plurality of signals to make a validity determination of the obtained acquisition assistance data;

calculating, based on the obtained acquisition assistance data and the validity determination, updated acquisition assistance data for a second of the plurality of signals; and

setting a code phase window size responsive to the updated acquisition assistance data.

2. The method of claim 1 wherein the receiver is a mobile station in a telecommunications system, the method further comprising the mobile station employing the measured parameters of the acquired first of the plurality of signals to calculate an estimated time of arrival for the second of the plurality of signals.

3. The method of claim 1 wherein the receiver is a mobile station in a telecommunications system, the method further comprising the mobile station employing the measured parameters of the acquired first of the plurality of signals to calculate a time of arrival uncertainty window for the second of the plurality of signals.

4. The method of claim 3 further comprising compensating an estimated time of arrival, based on the obtained acquisition assistance data, for movement of the receiver subsequent to obtaining the obtained acquisition assistance data.

5. The method of claim 3 further comprising compensating a calculated time of arrival uncertainty window, based on the obtained acquisition assistance data, for movement of the receiver subsequent to obtaining the obtained acquisition assistance data.

6. The method of claim 1 wherein the acquisition assistance data are obtained from the remote entity prior to determining to acquire the plurality of signals, the method further comprising evaluating a validity of the obtained acquisition assistance data for use in acquiring at least one of the plurality of signals.

8. The method of claim 1 further comprising determining that the receiver has moved based upon a combination of comparisons selected from (a) a present neighbor list of the receiver to a previous neighbor list of the receiver, (b) a present active base station list of the receiver to a previous active base station list of the receiver, and (c) a present serving base station for the receiver to a previous serving base station for the receiver.

7. The method of 1 further comprising determining that some previously received acquisition assistance data are invalid due to movement of the receiver subsequent to receiving the previously received acquisition assistance data.

9. A telecommunications system receiver comprising:

obtaining means for obtaining acquisition assistance data from an entity remote from the receiver;

acquiring means for acquiring a first of a plurality of signals at the receiver;

first employing means for employing measured parameters of the first of the plurality of signals to make a validity determination of the obtained acquisition assistance data;

means for calculating, based on the obtained acquisition assistance data and the validity determination, updated acquisition assistance data for a second of the plurality of signals; and

means for setting a code phase window size responsive to the updated acquisition assistance data.

10. The receiver of claim 9 wherein the receiver is a mobile station in a telecommunications system, the receiver further comprising second employing means for employing the measured parameters of the acquired first of the plurality of signals to calculate an estimated time of arrival for the second of the plurality of signals.

11. The receiver of claim 9 wherein the receiver is a mobile station in a telecommunications system, the receiver further comprising third employing means for employing the measured parameters of the acquired first of the plurality of signals to calculate a time of arrival uncertainty window for the second of the plurality of signals.

12. The receiver of claim 11 further comprising first means for compensating an estimated time of arrival, based on the obtained acquisition assistance data, for movement of the receiver subsequent to obtaining the obtained acquisition assistance data.

13. The receiver of claim 11 further comprising second means for compensating a calculated time of arrival uncertainty window, based on the obtained acquisition assistance data, for movement of the receiver subsequent to obtaining the obtained acquisition assistance data.

14. The receiver of claim 9 wherein the obtaining means are configured to obtain the acquisition assistance data from the remote entity prior to determining means determining to acquire the plurality of signals, the receiver further comprising means for evaluating a validity of the obtained acquisition assistance data for use in acquiring at least one of the plurality of signals.

16. The receiver of claim 9 further comprising means for determining that the receiver has moved based upon a combination of comparisons selected from (a) a present neighbor list of the receiver to a previous neighbor list of the receiver, (b) a present active base station list of the receiver to a previous active base station list of the receiver, and (c) a present serving base station for the receiver to a previous serving base station for the receiver.

15. The receiver of 9 further comprising means for determining that some previously received acquisition assistance data are invalid due to movement of the receiver subsequent to receiving the previously received acquisition assistance data.

17. A computer program product, for acquiring a signal at a telecommunications system receiver with the aid of acquisition assistance data, residing on a non-transitory processor-readable medium comprising instructions configured to cause the processor to:

determine to acquire a plurality of signals at the receiver;

acquire a first of the plurality of signals at the receiver;

employ measured parameters of the first of the plurality of signals to make a validity determination of acquisition assistance data from an entity remote from the receiver;

calculate, based on the acquisition assistance data and the validity determination, updated acquisition assistance data for a second of the plurality of signals; and

set a code phase window size responsive to the updated acquisition assistance data.

18. The computer program product of claim 17 further comprising instructions configured to cause the processor to employ the measured parameters of the acquired first of the plurality of signals to calculate an estimated time of arrival for the second of the plurality of signals.

19. The computer program product of claim 17 further comprising instructions configured to cause the processor to employ the measured parameters of the acquired first of the plurality of signals to calculate a time of arrival uncertainty window for the second of the plurality of signals.

20. The computer program product of claim 19 further comprising instructions configured to cause the processor to compensate an estimated time of arrival, based on the obtained acquisition assistance data, for movement of the receiver subsequent to the acquisition assistance data being obtained.

21. The computer program product of claim 19 further comprising instructions configured to cause the processor to compensate a calculated time of arrival uncertainty window, based on the acquisition assistance data, for movement of the receiver subsequent to the acquisition assistance data being obtained.

22. The computer program product of claim 17 further comprising instructions configured to cause the processor to evaluate a validity of the acquisition assistance data for use in acquiring at least one of the plurality of signals.

23. The computer program product of claim 17 further comprising instructions configured to cause the processor to determine that some previously received acquisition assistance data are invalid due to movement of the receiver subsequent to receiving the previously received acquisition assistance data.

24. The computer program product of claim 17 further comprising instructions configured to cause the processor to determine that the receiver has moved based upon a combination of comparisons selected from (a) a present neighbor list of the receiver to a previous neighbor list of the receiver, (b) a present active base station list of the receiver to a previous active base station list of the receiver, and (c) a present serving base station for the receiver to a previous serving base station for the receiver.