Electronic device precision location via local broadcast signals

• US 6,806,830 B2
• Filed: 12/31/2001
• Issued: 10/19/2004
• 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.
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US10/036,700
• Publication Number:
  US 20030122711A1
• Time in Patent Office: 1,023 Days
• Field of Search: 342/457, 342/387, 342/385, 342/386, 342/464, 455/456.1
• US Class Current: 342/464
• 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 transmitted from known transmitter locations, said broadcast signals each including a synchronization signal locked to a common time; and

an apparatus for receiving said broadcast signals and calculating the location of said apparatus using time differences detected amongst respective ones of said received synchronization signals.

2. The system of claim 1, wherein said broadcast signals are 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 apparatus is 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 apparatus receives broadcast signals from at least three transmitter locations.

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

LMU”

.

9. A position location system, comprising:

broadcast signals with common synchronization from at least one satellite and rebroadcast from three or more known terrestrial re-transmitter locations; and

an apparatus for receiving said rebroadcast signals and calculating the location of said apparatus using time differences detected in synchronization between respective ones of said received rebroadcast signals.

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

receiving non-DTV broadcast signals transmitted from known transmitter locations, said broadcast signals each having a synchronization signal locked to a common time when transmitted; and

calculating the location of said electronic device using time differences detected amongst respective ones of said synchronization signals in said received broadcast signals.

11. The method of claim 10, wherein said broadcast signals are analog signals with digital sub-carrier signals.

12. The method of claim 10, wherein said broadcast signals are digital signals.

13. The method of claim 12, wherein said digital signals are re-transmissions of satellite radio signals.

14. The method of claim 12, wherein said receiving non-DTV broadcast signals is enabled by an RF receiver in said electronic device.

15. The method of claim 10, wherein said electronic device is a cellular handset.

16. The method of claim 10, wherein said electronic device receives broadcast signals from at least three transmitter locations.

17. The method of claim 10, wherein correction of non-time locked broadcast signals is provided by a local monitoring unit “

LMU”

.

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

receiving broadcast signals from three or more terrestrial transmitter locations, each of said broadcast signals being a retransmission with common synchronization of a signal previously transmitted by a satellite; and

calculating the location of said electronic device using time differences detected in synchronization between respective ones of said received broadcast signals.

19. An electronic apparatus enabled to receive non-DTV broadcast signals transmitted from known transmitter locations in which said broadcast signals each include a synchronization signal locked to a common time at time of transmission and further enabled to calculate the location of said apparatus using time differences detected amongst respective ones of said synchronization signals in said received broadcast signals.

20. The apparatus of claim 19, wherein said apparatus is a cellular transceiver.

21. The apparatus of claim 20, wherein said known locations are provided by a lookup table in communication with said transceiver.

22. The apparatus of claim 21, wherein said lookup table is in a server responsive to the transceiver.

23. The apparatus of claim 21, wherein said lookup table is in said apparatus.

24. An electronic apparatus enabled to receive broadcast signals from three or more terrestrial transmitter locations, each of said broadcast signals being a retransmission with common synchronization of a signal previously transmitted by a satellite, and further enabled to calculate the location of said apparatus using time differences detected in synchronization between respective ones of said received broadcast signals.

25. A position location system, comprising:

at least three transmitters in which the location of each of the transmitters is known;

non-DTV broadcast signals transmitted from said known transmitter locations, said broadcast signals each including a synchronization signal locked to a common time; and

an apparatus for receiving said broadcast signals and calculating the location of said apparatus using time differences detected amongst respective ones of said received synchronization signals.

26. A position location system, comprising:

at least three transmitters for rebroadcasting a broadcast signal from a satellite in which the location of each of the transmitters is known, said rebroadcast signal transmitted from any one of said three transmitters being commonly synchronized with the rebroadcast signals transmitted from the other transmitters; and

an apparatus for receiving said rebroadcast signals and calculating the location of said apparatus using time differences detected in synchronization between respective ones of said received rebroadcast signals.