Method and System for Processing Positioning Signals Based on Predetermined Message Data Segment

• US 20070120735A1
• Filed: 12/22/2006
• Published: 05/31/2007
• Est. Priority Date: 07/18/2001
• Status: Active Grant

• Current Assignee: Fast Location.Net, LLC
• Original Assignee: Fast Location.Net, LLC
• Inventors: Wise, Michael, Jandrell, Louis, Bromley, Patrick
• Granted Patent: US 7,633,439 B2
• Time in Patent Office: Days
• US Class Current: 342/357.640
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/09 providing processing capability normally carried out by the receiver
• CPC Class Codes: G01S 19/17 Emergency applications
• CPC Class Codes: G01S 19/235 Calibration of receiver components
• CPC Class Codes: G01S 19/254 relating to Doppler shift of satellite signals
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• 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 19/29 carrier including Doppler, related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 19/35 Constructional details or hardware or software details of the signal processing chain
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: G01S 5/0018 Transmission from mobile station to base station
• CPC Class Codes: G01S 5/0063 of measured values, i.e. measurement on base station and position calculation on mobile

Abstract

A method and system for determining a geolocation of an object includes collecting a positioning signal including a predetermined message data segment. A time of arrival of the predetermined message data segment may be determined in the positioning signal. Information based on the time of arrival may be provided for determination of a geolocation of an object. The time of arrival of the predetermined message data segment may be determined based on a time search for the predetermined message data segment in the positioning signal.

Claims

1. A method for determining a geolocation of an object, comprising:

collecting a plurality of positioning signals each including a predetermined message data segment, the positioning signals being generated by one or more satellites;

identifying the predetermined message data segment in each of the plurality of positioning signals;

determining a time of arrival of the predetermined message data segment upon identification in each of the collected positioning signals;

determining a time difference between at least two of the collected positioning signals based on the respective times of arrival of the respective predetermined message data segments;

determining a geolocation of the object based on the time difference.

2. The method of claim 1, further comprising:

compensating for carrier frequency offset (CFO) of the one or more satellites prior to determining the time of arrival.

3. The method of claim 1, wherein the satellite generated positioning signals include either global positioning system (GPS) or global navigation satellite system (GLONASS) positioning signals.

4. The method of claim 1, further comprising:

receiving a trigger to initiate positioning signal collection;

identifying a clock error upon positioning signal collection initiation.

5. The method of claim 1, further comprising:

selecting one or more in-view satellites transmitting the plurality of positioning signals;

determining a propagation time from each selected in-view satellite.

6. The method of claim 1, further comprising:

determining the geolocation of the object based on the time of arrival.

7. The method of claim 6, further comprising:

calibrating a clock based on the known time of transmission of the predetermined message data segment and a range between the object and the one or more satellites.

8. The method of claim 1, further comprising:

determining the time of arrival based on a time search for the predetermined message data segment in the positioning signal.

9. The method of claim 1, further comprising:

providing the positioning signals in a superframe;

selecting a portion of the superframe to be the predetermined message data segment.

10. The method of claim 9, wherein the selected portion of the superframe includes handover information.

11. A computer readable medium including code for determining a geolocation of an object, the code operable to:

receive a plurality of positioning signals each including a predetermined message data segment, the positioning signals being generated by one or more satellites;

identify the predetermined message data segment in each of the plurality of positioning signals, the predetermined message data segment being identical in each positioning signal and being transmitted within each positioning signal at an identical moment in time;

determine a time of arrival of the predetermined message data segment upon identification in each of the received positioning signals;

determine a time difference between at least two of the received positioning signals based on the respective times of arrival of the respective predetermined message data segments;

determine a geolocation of the object based on the time difference.

12. The computer readable medium of claim 11, wherein the code is further operable to:

compensate for carrier frequency offset (CFO) of the satellites prior to determining the time of arrival.

13. The computer readable medium of claim 11, wherein the satellite generated positioning signals include either global positioning system (GPS) or global navigation satellite system (GLONASS) positioning signals.

14. The computer readable medium of claim 11, wherein the code is further operable to:

receive a trigger to initiate positioning signal collection;

identify a clock error upon positioning signal collection initiation.

15. The computer readable medium of claim 11, wherein the code is further operable to:

select one or more in-view satellites transmitting the plurality of positioning signals,

determine a propagation time from each selected in-view satellite.

16. The computer readable medium of claim 11, wherein code is further operable to:

determine the geolocation of the object based on the time of arrival.

17. The computer readable medium of claim 16, wherein the code is further operable to:

calibrate a clock based on the known time of transmission of the predetermined message data segment and a range between the object and the one or more satellites.

18. The computer readable medium of claim 11, wherein the code is further operable to:

determine the time of arrival based on a time search for the predetermined message data segment in the positioning signals.

19. The computer readable medium of claim 11, wherein the code is further operable to:

provide the positioning signals in a superframe;

select a portion of the superframe to be the predetermined message data segment.

20. The computer readable medium of claim 18, wherein the selected portion of the superframe includes handover information.

21. A system for determining a geolocation of an object, comprising:

means for collecting a positioning signal including a predetermined message data segment, the positioning signal being generated by a satellite;

means for identifying the predetermined message data segment in each of the plurality of positioning signals, the predetermined message data segment being identical in each positioning signal and is transmitted within each positioning signal at an identical moment in time;

means for determining a time of arrival of the predetermined message data segment upon identification in the positioning signal;

means for determining a geolocation of the object based on the time of arrival.

22. The system of claim 21, further comprising:

means for compensating for carrier frequency offset (CFO) prior to determining the time of arrival.

23. The system of claim 21, wherein the satellite generated positioning signals include either global positioning system (GPS) or global navigation satellite system (GLONASS) positioning signals.

24. The system of claim 21, further comprising:

means for receiving a trigger to initiate positioning signal collection;

means for identifying a clock error upon positioning signal collection initiation.

25. The system of claim 21, further comprising:

means for selecting an in-view satellite transmitting the positioning signal;

means for determining a propagation time from the selected in-view satellite.

26. The system of claim 21, further comprising:

means for determining the geolocation of the object based on the time of arrival.

27. The system of claim 26, further comprising:

means for calibrating a clock based on the known time of transmission of the predetermined message data segment and a range between the object and the satellite.

28. The system of claim 21, further comprising:

means for determining the time of arrival based on a time search for the predetermined message data segment in the positioning signal.

29. The system of claim 21, further comprising:

means for providing the positioning signals in a superframe;

means for selecting a portion of the superframe to be the predetermined message data segment.

30. The system of claim 21, wherein the selected portion of the superframe includes handover information.