System and method to obtain signal acquisition assistance data

• US 8,692,711 B2
• Filed: 08/19/2011
• Issued: 04/08/2014
• Est. Priority Date: 04/25/2003
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gaal, Peter, Sheynblat, Leonid, Patrick, Christopher, Riley, Wyatt Thomas
• Primary Examiner(s): Issing, Gregory C
• Application Number:
  US13/214,047
• Publication Number:
  US 20120040689A1
• Time in Patent Office: 963 Days
• Field of Search: 342/357.63, 342/357.65, 342/357.71
• US Class Current: 342/357.63
• 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 evaluating acquisition assistance data in a wireless telecommunications system, the method comprising:

a) obtaining, at a telecommunications entity in the wireless telecommunications system, a first list of base stations relevant to the mobile station according to particular criteria at a first time;

b) obtaining, at the telecommunications entity, a second list of base stations relevant to the mobile station according to the particular criteria at a second time, later than the first time; and

c) making, at the telecommunications entity, a comparison of the second list of relevant base stations and the first list of base stations; and

d) evaluating, at the telecommunications entity, a validity of previously obtained acquisition assistance data based in part on the comparison to determine whether to update the previously obtained acquisition assistance data or to use the previously obtained acquisition assistance data to acquire a signal.

2. The method of claim 1 wherein the lists of base stations are of active sets of base stations.

3. The method of claim 1 further comprising performing steps a), b) and c) for base stations that are relevant to the mobile station according to a second set of criteria.

4. The method of claim 1 wherein the second set of base stations is a neighbor list.

5. The method of claim 1 further comprising combining results of the comparison in step c) of the first and second lists of base stations belonging to a set relevant to the mobile station according to the particular criteria with results of a comparison of base stations belonging to a different set that is relevant to the mobile station according to second criteria.

6. The method of claim 1 wherein the telecommunications entity is a mobile station and the signal to acquire is a Global Positioning System signal, the method further comprising calculating a location of the mobile station.

7. An apparatus for evaluating acquisition assistance data in a wireless telecommunications system, the apparatus comprising:

a) obtaining means for obtaining first and second lists of base stations relevant to the mobile station according to at least a first criterion at first and second times, respectively, with the second time being later than the first time;

b) comparing means for making a comparison of the second list of base stations and the first list of base stations; and

c) evaluating means for evaluating a validity of previously obtained acquisition assistance data based in part on the comparison to determine whether to update the previously obtained acquisition assistance data or to use the previously obtained acquisition assistance data to acquire a signal.

8. The apparatus of claim 7 wherein the lists of base stations are of active sets of base stations.

9. The apparatus of claim 7 wherein the obtaining means are further for obtaining third and fourth lists of base stations relevant to the mobile station according to at least a second criterion and wherein the comparing means are further for making a comparison of the third and fourth lists.

10. The apparatus of claim 9 further comprising means for combining results of the comparison of the first and second lists with results of the comparison of the third and fourth lists.

11. The apparatus of claim 7 wherein the second set of base stations is a neighbor list.

12. The apparatus of claim 7 wherein the signal to acquire is a Global Positioning System signal, the apparatus further comprising calculating means for calculating a location of a mobile station of the telecommunications system.

13. A computer program product residing on a non-transitory processor-readable medium of a wireless telecommunications system for use in evaluating location-related information, the computer program product comprising processor-readable instructions configured to cause a processor to:

a) obtain a first list of base stations relevant to the mobile station according to first criteria at a first time;

b) obtain a second list of base stations relevant to the mobile station according to the first criteria at a second time, the second time being after the first time; and

c) make a comparison of the first list of base stations and the second list of base stations; and

d) evaluate a validity of previously obtained acquisition assistance data based in part on the comparison to determine whether to update the previously obtained acquisition assistance data or to use the previously obtained acquisition assistance data to acquire a signal.

14. The computer program product of claim 13 wherein the first and second lists of base stations are of active sets of base stations.

15. The computer program product of claim 13 further comprising instructions configured to cause the processor to:

d) obtain a third list of base stations relevant to the mobile station according to second criteria at a third time;

e) obtain a fourth list of base stations relevant to the mobile station according to the second criteria at a fourth time, the fourth time being after the third time; and

f) make a comparison of the third list of base stations and the fourth list of base stations.

16. The computer program product of claim 15 further comprising instructions configured to cause the processor to combine results of the comparison of the first and second lists with results of the comparison of the third and fourth lists.

17. The computer program product of claim 13 wherein the second set of base stations is a neighbor list.

18. The computer program product of claim 13 wherein the signal to acquire is a Global Positioning System signal, the computer program product further comprising instructions configured to cause the processor to calculate a location of a mobile station of the telecommunications system.