SYSTEM AND/OR METHOD FOR ACQUISITION OF GNSS SIGNALS

• US 20110298662A1
• Filed: 08/16/2011
• Published: 12/08/2011
• Est. Priority Date: 09/14/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Pon, Rayman Wai
• Granted Patent: US 8,502,732 B2
• Time in Patent Office: Days
• US Class Current: 342/357.63
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/28 Satellite selection
• CPC Class Codes: G01S 19/29 carrier including Doppler, related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/30 code related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/33 Multimode operation in different systems which transmit time stamped messages, e.g. GPS/GLONASS

Abstract

The subject matter disclosed herein relates to a system and method for acquiring signal received from space vehicles (SVs) in a satellite navigation system. In one example, although claimed subject matter is not so limited, information processed in acquiring a signal from a first SV may be used in acquiring a signal from a second SV.

Claims

1. A method comprising:

detecting a first Doppler frequency in a first signal received from a first space vehicle (SV) at a reference location; and

determining a search range for detecting a second Doppler frequency in a second signal received at the reference location from a second SV based, at least in part, on the detected first Doppler frequency.

2. The method of claim 1 wherein the determining the search range further comprises determining the search range based, at least in part, on an uncertainty in an estimate of the reference location.

3. The method of claim 1 wherein the determining the search range further comprises determining a center of the search range based, at least in part, on the detected first Doppler frequency.

4. The method of claim 3 wherein the determining the search range further comprises determining a Doppler search window about the center of the search range based, at least in part, on an uncertainty in an estimate of the reference location.

5. An article comprising:

a tangible storage medium comprising machine-readable instructions stored thereon which, if executed by a computing platform, are adapted to cause the computing platform to;

determine a first Doppler frequency in a first signal received from a first space vehicle (SV) at a reference location; and

determine a search range for detecting a second Doppler frequency in a second signal received at the reference location from a second SV based, at least in part, on the detected first Doppler frequency.

6. The article of claim 5 wherein the instructions adapted to cause the computing platform to determine the search range further comprise instructions adapted to cause the computing platform to determine the search range based, at least in part, on an uncertainty in an estimate of the reference location.

7. The article of claim 5 wherein the instructions adapted to cause the computing platform to determine the search range further comprise instructions adapted to cause the computing platform to determine a center of the search range based, at least in part, on the detected first Doppler frequency.

8. The article of claim 7 wherein the instructions adapted to cause the computing platform to determine the search range further comprise instructions adapted to cause the computing platform to determine a Doppler search window about the center of the search range based, at least in part, on an uncertainty in an estimate of the reference location.

9. A subscriber unit comprising:

a receiver configured to receive an acquisition assistance (AA) message comprising information indicative of an uncertainty of an estimate of a reference location, the subscriber unit being adapted to;

detect a first Doppler frequency in a first signal received from a first space vehicle (SV) at a reference location; and

determine a search range for detecting a second Doppler frequency in a second signal received at the reference location from a second SV based, at least in part, on the detected first Doppler frequency and the information indicative of the uncertainty.

10. The subscriber unit of claim 9 wherein the subscriber unit is further adapted to receive the AA message over a wireless communication link.

11. The subscriber unit of claim 9 wherein the subscriber unit is further adapted to determine the search range based, at least in part, on an uncertainty in an estimate of the reference location.

12. The subscriber unit of claim 9 wherein the subscriber unit is further adapted to determine the search range by determining a center of the search range based, at least in part, on the detected first Doppler frequency.

13. The subscriber unit of claim 12 wherein the subscriber unit is further adapted to determine the search range by determining a Doppler search window about the center of the search range based, at least in part, on an uncertainty in an estimate of the reference location.

14. A system comprising:

means for detecting a first Doppler frequency in a first signal received from a first space vehicle (SV) at a reference location; and

means for determining a search range for detecting a second Doppler frequency in a second signal received at the reference location from a second SV based, at least in part, on the detected first Doppler frequency.

15. The system of claim 14 wherein the means for determining the search range are configured to determine the search range based, at least in part, on an uncertainty in an estimate of the reference location.

16. The method of claim 14 wherein the means for determining the search range are configured to determine a center of the search range based, at least in part, on the detected first Doppler frequency.

17. The method of claim 16 wherein the means for determining the search range are configured to determine a Doppler search window about the center of the search range based, at least in part, on an uncertainty in an estimate of the reference location.

18. A system comprising:

a position determination entity (PDE); and

a subscriber unit adapted to;

receive an acquisition assistance (AA) message from the PDE over a wireless communication link, the AA message comprising information indicative of an uncertainty of an estimate of a reference location;

detect a first Doppler frequency in a first signal received from a first space vehicle (SV) at a reference location; and

determine a search range for detecting a second Doppler frequency in a second signal received at the reference location from a second SV based, at least in part, on the detected first Doppler frequency and the information indicative of the uncertainty.