Methods and apparatuses for estimating time relationship information between navigation systems

Patent metadata

Field	Value
Publication number	US-9244176-B2
Application number	US-61263509-A
Country	US
Kind code	B2
Filing date	Nov 4, 2009
Priority date	Nov 4, 2009
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

Methods and apparatuses are provided that may be implemented in various electronic devices to possibly reduce a first-time-to-fix and/or otherwise increase the performance or efficiency of a device by employing a position/velocity estimation process using at least one estimated time relationship parameter.

First claim

What is claimed is:

1. A method, comprising:
with a device configured to receive and process satellite positioning system (SPS) signals associated with at least first and second navigation systems:
generating one or more electronic signals representing an estimated time bias (TB) parameter based, at least in part, on a differential group delay (GD) parameter associated with said device and a time offset (TO) parameter associated with said first navigation system and said second navigation system, wherein one or more electronic signals representing said TO parameter are generated based, at least in part, on said differential GD parameter; and
selectively generating one or more electronic signals representing a pseudorange (PR) measurement corresponding to said device and at least one space vehicle (SV) of either said first or second navigation systems based, at least in part, on said estimated TB parameter.

2. The method as recited in claim 1 , wherein said first navigation system is operatively associated with a first system time and said second navigation system is operatively associated with a second system time that is offset from said first system time by a dynamically changing offset value, wherein said TO parameter is associated with said dynamically changing offset value.

3. The method as recited in claim 2 , further comprising, with said device:
receiving one or more electronic signals representing said TO parameter.

4. The method as recited in claim 1 , wherein said differential GD parameter is predetermined.

5. The method as recited in claim 1 , further comprising, with said device:
generating one or more electronic signals representing said differential GD parameter based, at least in part, on at least one of a temperature parameter or a previously stored TB parameter.

6. The method as recited in claim 1 , wherein the selectively generating said one or more electronic signals representing said PR measurement further comprises:
verifying that said estimated TB parameter is acceptable for use based, at least in part, on at least one uncertainty measurement associated with said estimated TB parameter.

7. The method as recited in claim 1 , further comprising, with said device:
obtaining one or more electronic signals representing a first plurality of SPS signals associated with said first navigation system, wherein a first total number of available SPS signals associated with said first navigation system does not satisfy a minimum number of SPS signals to compute an estimated position of said device; and
obtaining one or more electronic signals representing at least one SPS signal associated with said second navigation system, and wherein a second total number of available SPS signals associated with said second navigation system also does not satisfy said minimum number of SPS signals to compute said estimated position of said device, but wherein said first and second total number of available SPS signals summed together does satisfy said minimum number of SPS signals to compute said estimated position of said device.

8. The method as recited in claim 7 , wherein said minimum number of SPS signals to compute said estimated position of said device is three provided that an altitude parameter is available, or four otherwise.

9. The method as recited in claim 7 , wherein said minimum number of SPS signals to compute said estimated position of said device is four provided that an altitude parameter is available, or five otherwise.

10. The method as recited in claim 1 , wherein at least one of said first or second navigation systems comprises a Global Navigation Satellite System (GNSS).

11. The method of claim 1 , wherein the one or more electronic signals representing said TO parameter are generated by subtracting said differential GD parameter from a previously stored TB parameter.

12. The method of claim 11 , wherein said previously stored TB parameter is determined based on a previous position fix that was conducted using said first navigation system and said second navigation system independently.

13. The method of claim 1 , further comprising generating one or more electronic signals for input to a positioning calculation, wherein said one or more electronic signals are based, at least in part, on said PR measurement.

14. The method of claim 1 , further comprising generating one or more electronic signals to enable said device to determine an estimated position of said device, wherein said one or more electronic signals are based, at least in part, on:
said PR measurement; and
at least three additional stored PR measurements.

15. An apparatus, comprising:
means for receiving satellite positioning system (SPS) signals associated with at least first and second navigation systems;
means for determining an estimated time bias (TB) parameter based, at least in part, on a differential group delay (GD) parameter associated with said apparatus and a time offset (TO) parameter associated with said first and second navigation systems, wherein said means for determining said estimated TB include means for generating one or more electronic signals representing said TO parameter based, at least in part, on said differential GD parameter; and
means for selectively determining a pseudorange (PR) measurement corresponding to said apparatus and at least one space vehicle (SV) of either said first or second navigation systems based, at least in part, on said estimated TB parameter.

16. The apparatus as recited in claim 15 , wherein said first navigation system is operatively associated with a first system time and said second navigation system is operatively associated with a second system time that is offset from said first system time by a dynamically changing offset value, wherein said TO parameter is associated with said dynamically changing offset value.

17. The apparatus as recited in claim 16 , further comprising:
means for receiving one or more electronic signals representing said TO parameter.

18. The apparatus as recited in claim 15 , wherein said differential GD parameter is predetermined.

19. The apparatus as recited in claim 15 , further comprising:
means for determining said differential GD parameter based, at least in part, on at least one of a temperature parameter or a previously stored TB parameter.

20. The apparatus as recited in claim 15 , further comprising:
means for verifying that said estimated TB parameter is acceptable for use based, at least in part, on at least one uncertainty measurement associated with said estimated TB parameter.

21. The apparatus as recited in claim 15 , further comprising:
means for obtaining one or more electronic signals representing a first plurality of SPS signals associated with said first navigation system, wherein a first total number of available SPS signals associated with said first navigation system does not satisfy a minimum number of SPS signals to compute an estimated position of said device; and
means for obtaining one or more electronic signals representing at least one SPS signal associated with said second navigation system, and wherein a second total number of available SPS signals associated with said second navigation system also does not satisfy said minimum number of SPS signals to compute said estimated position of said device, but wherein said first and second total number of available SPS signals summed together does satisfy said minimum number of SPS signals to compute said estimated position of said device.

Assignees

• Morrison William James
• Qualcomm Inc

Inventors

• Morrison William James

Classifications

• G01S19/33 Primary

  Multimode operation in different systems which transmit time stamped messages, e.g. GPS/GLONASS · CPC title

• G01S19/425

  by combining or switching between signals derived from different satellite radio beacon positioning systems · CPC title