Electronic device precision location via local broadcast signals

• US 20030122711A1
• Filed: 12/31/2001
• Published: 07/03/2003
• Est. Priority Date: 12/31/2001
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Lazar, Steven C., Pedigo, Madison F., Panasik, Carl M.
• Granted Patent: US 6,806,830 B2
• Time in Patent Office: Days
• US Class Current: 342/387
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 5/02 using radio waves using satellite radio beacon systems for determining position G01S19/00
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0226 Transmitters
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308

Abstract

A location determination apparatus, method and system (10, 23, 26, 32, 36, 48, 52, 60, 64, 74, 78, 84, 90, 106) that is an improvement upon existing location determining techniques. The invention enables precision indoor location determination through the use of non-DTV terrestrial broadcast signals (e.g. one way, wide area, dissemination of information)(20), or re-broadcast signals (44, 56, 70, 80) of the proposed (terrestrial based) digital satellite radio relay transmitters (42, 54) to provide position location. This solution does not require a local receiver to correct for long distance propagation dispersion, particularly for the satellite relay, as the digital radio satellites are already synchronized to GPS time. More specifically, the invention discloses two significant location detection concepts: A) local terrestrial transmitters (12) provide information used to determine the location of an electronic apparatus; and B) local re-transmitters of satellite-distributed programming (42, 54) provide information used to determine the location of an electronic apparatus.

Claims

1. A position location system, comprising:

non-DTV broadcast signals with synchronization from known transmitter locations;

an RF receiver for receiving said synchronization; and

means for calculating the location of said RF receiver using time differences provided by said synchronization.

2. The system of claim 1, wherein said broadcast signals are present day analog signals with digital sub-carrier signals.

3. The system of claim 1, wherein said broadcast signals are digital signals.

4. The system of claim 3, wherein said digital signals are re-transmissions of satellite radio signals.

5. The system of claim 1, wherein said RF receiver is incorporated in a cellular transceiver.

6. The system of claim 5, wherein said cellular transceiver is a personal communicator.

7. The system of claim 1, wherein said RF receiver receives at least three broadcast signals.

8. The system of claim 1, wherein said broadcast signals further include a common time lock reference.

9. The system of claim 1, wherein correction of non-time locked broadcast signals is provided by a local monitoring unit “

LMU”

.

10. A position location system, comprising:

broadcast signals with synchronization from known re-transmitter locations;

an RF receiver for receiving said synchronization; and

means for calculating the location of said RF receiver using timing provided by said synchronization.

11. A method for locating an electronic device, comprising the steps of:

receiving non-DTV broadcast signals, said broadcast signals having a synchronization signal; and

calculating the location of said RF receiver using time differences provided by said synchronization.

12. The method of claim 11, wherein said broadcast signals are present day analog signals with digital sub-carrier signals.

13. The method of claim 11, wherein said broadcast signals are digital signals.

14. The method of claim 13, wherein said digital signals are re-transmissions of satellite radio signals.

15. The method of claim 11, wherein said RF receiver is incorporated in a cellular transceiver.

16. The method of claim 11, wherein said cellular transceiver is a cellular handset.

17. The method of claim 11, wherein said RF receiver receives at least three broadcast signals.

18. The method of claim 11, wherein said broadcast signals further include a common time lock reference.

19. The method of claim 11, wherein correction of non-time locked broadcast signals is provided by a local monitoring unit “

LMU”

.

20. A method for locating an electronic device, comprising the steps of:

receiving re-broadcast signals, said re-broadcast signals having a synchronization signal; and

calculating the location of said RF receiver using time differences provided by said synchronization and known locations of the transmitter of said re-broadcast signals.

21. An electronic apparatus, comprising:

an RF receiver for receiving synchronization from non-DTV broadcast signals transmitted from known locations and calculating the location of said RF receiver using time differences provided by said synchronization.

22. The apparatus of claim 21, wherein said receiver is incorporated into a cellular transceiver.

23. The apparatus of claim 22, wherein said known locations are provided by a lookup table in communication with said transceiver.

24. The apparatus of claim 23, wherein said lookup table is in a server responsive to the transceiver.

25. The apparatus of claim 23, wherein said lookup table is in said apparatus.