Position location using ghost canceling reference television signals

• US 6,522,297 B1
• Filed: 05/31/2002
• Issued: 02/18/2003
• Est. Priority Date: 02/02/2001
• Status: Expired due to Term

• Current Assignee: TruePosition Incorporated
• Original Assignee: Rosum Corporation (Liberty Broadband Corp.)
• Inventors: Rabinowitz, Matthew, Spilker, Jr., James J.
• Primary Examiner(s): PHAN, DAO LINDA
• Application Number:
  US10/159,831
• Time in Patent Office: 263 Days
• Field of Search: 342/450, 342/457, 342/463, 342/458, 342/465
• US Class Current: 342/458
• CPC Class Codes: A63F 2300/205 for detecting the geographical location of the game platform
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/0054 of actual mobile position, i.e. position calculation on base station
• CPC Class Codes: G01S 5/0081 Transmission between base stations
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0215 Interference
• CPC Class Codes: G01S 5/0226 Transmitters
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G01S 5/145 Using a supplementary range measurement, e.g. based on pseudo-range measurements
• CPC Class Codes: H04N 21/25841 involving the geographical location of the client retrieval from the Internet by querying based on geographical locations G06F16/9537; arrangements for identifying locations of receiving stations in broadcast systems H04H60/51; location of the user terminal in data switching networks H04L67/52; services making use of the location of users or terminals in wireless networks H04W4/02; locating users or terminals in wireless networks H04W64/00
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/2668 Creating a channel for a dedicated end-user group, e.g. insertion of targeted commercials based on end-user profiles information retrieval from the Internet by querying with filtering and personalisation G06F16/9535; arrangements for replacing or switching information during the broadcast H04H20/10; push services over packet-switching network H04L12/1859; adaptation of message content in packet-switching networks H04L51/063
• CPC Class Codes: H04N 21/41422 located in transportation means, e.g. personal vehicle arrangements specially adapted for transportation systems in broadcast systems H04H20/62
• CPC Class Codes: H04N 21/615 Signal processing at physical level signal processing in analog two-way television systems H04N7/173
• CPC Class Codes: H04N 21/8126 involving additional data, e.g. news, sports, stocks, weather forecasts

Abstract

A method, apparatus, and computer-readable media for determining the position of a user terminal comprises generating a correlation reference signal based on known characteristics of a chirp-type signal present in a broadcast analog television signal; receiving, at the user terminal, a broadcast analog television signal comprising the chirp-type signal; and correlating the broadcast analog television signal with the correlation reference signal, thereby producing a pseudorange; and wherein the location of the user terminal is determined based on the pseudorange and a location of the transmitter of the broadcast analog television signal.

Claims

1. A method for determining the position of a user terminal, comprising:

generating a correlation reference signal based on known characteristics of a broadcast analog television, ghost canceling reference signal;

receiving, at the user terminal, a broadcast analog television signal comprising the ghost canceling reference signal; and

correlating the broadcast analog television signal with the correlation reference signal, thereby producing a pseudorange; and

wherein

the location of the user terminal is determined based on the pseudorange and a location of the transmitter of the broadcast analog television signal.

2. The method of claim 1, further comprising:

determining the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.

3. The method of claim 2, further comprising:

determining the location of the user terminal based on the pseudorange, a pseudorange computed based on a broadcast digital television signal, and the locations of the transmitters of the broadcast analog television signal and the broadcast digital television signal.

4. The method of claim 1, further comprising:

identifying the peak of the result of the correlating, thereby producing the pseudorange.

5. The method of claim 1, wherein the position of the user terminal is determined by adjusting the pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.

6. The method of claim 1, further comprising:

determining a further pseudorange based on a further broadcast analog television signal; and

projecting the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.

7. The method of claim 1, further comprising:

tracking the ghost canceling reference signal using a time-gated delay-lock loop.

8. An apparatus for determining the position of a user terminal, comprising:

means for generating a correlation reference signal based on known characteristics of a broadcast analog television ghost canceling reference signal;

means for receiving, at the user terminal, a broadcast analog television signal comprising the ghost canceling reference signal; and

means for correlating the broadcast analog television signal with the correlation reference signal, thereby producing a pseudorange; and

wherein

the location of the user terminal is determined based on the pseudorange and a location of the transmitter of the broadcast analog television signal.

9. The apparatus of claim 8, further comprising:

means for determining the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.

10. The apparatus of claim 9, further comprising:

determining the location of the user terminal based on the pseudorange, a pseudorange computed based on a broadcast digital television signal, and the locations of the transmitters of the broadcast analog television signal and the broadcast digital television signal.

11. The apparatus of claim 8, further comprising:

means for identifying the peak of the result of the correlating, thereby producing the pseudorange.

12. The apparatus of claim 8, wherein the position of the user terminal is determined by adjusting the pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.

13. The apparatus of claim 8, further comprising:

means for determining a further pseudorange based on a further broadcast analog television signal; and

means for projecting the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.

14. The apparatus of claim 8, father comprising:

means for tracking the ghost canceling reference signal using a time-gated delay-lock loop.

15. An apparatus for determining the position of a user terminal, comprising:

a signal generator to generate a correlation reference signal based on known characteristics of a broadcast analog television ghost canceling reference signal;

a receiver to receive, at the user terminal, a broadcast analog television signal comprising the ghost canceling reference signal; and

a correlator to correlate the broadcast analog television signal with the correlation reference signal, thereby producing a pseudorange; and

wherein

the location of the user terminal is determined based on the pseudorange and a location of the transmitter of the broadcast analog television signal.

16. The apparatus of claim 15, further comprising:

a processor to determine the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.

17. The apparatus of claim 16, wherein the processor determines the location of the user terminal based on the pseudorange, a pseudorange computed based on a broadcast digital television signal, and the locations of the transmitters of the broadcast analog television signal and the broadcast digital television signal.

18. The apparatus of claim 15, wherein the processor identifies the peak of the result of the correlating, thereby producing the pseudorange.

19. The apparatus of claim 15, wherein the position of the user terminal is determined by adjusting the pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.

20. The apparatus of claim 15, wherein the processor:

determines a further pseudorange based on a further broadcast analog television signal; and

projects the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.

21. The apparatus of claim 15, further comprising:

a time-gated delay-lock loop to track the ghost canceling reference signal.

22. Computer-readable media embodying instructions executable by a computer to perform a method for determining the position of a user terminal, the method comprising:

generating a correlation reference signal based on known characteristics of a broadcast analog television ghost canceling reference signal;

receiving, at the user terminal, a broadcast analog television signal comprising the ghost canceling reference signal; and

correlating the broadcast analog television signal with the correlation reference signal, thereby producing a pseudorange; and

wherein

the location of the user terminal is determined based on the pseudorange and a location of the transmitter of the broadcast analog television signal.

23. The media of claim 22, wherein the method further comprises:

determining the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.

24. The media of claim 23, wherein the method further comprises:

determining the location of the user terminal based on the pseudorange, a pseudorange computed based on a broadcast digital television signal, and the locations of the transmitters of the broadcast analog television signal and the broadcast digital television signal.

25. The media of claim 22, wherein the method further comprises:

identifying the peak of the result of the correlating, thereby producing the pseudorange.

26. The media of claim 22, wherein the position of the user terminal is determined by adjusting the pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.

27. The media of claim 22, wherein the method further comprises:

determining a further pseudorange based on a further broadcast analog television signal; and

projecting the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.

28. The media of claim 22, wherein the method further comprises:

tracking the ghost canceling reference signal using a time-gated delay-lock loop.

29. A method for determining the position of a user terminal, comprising:

generating a correlation reference signal based on known characteristics of a chirp-type signal present in a broadcast analog television signal;

receiving, at the user terminal, a broadcast analog television signal comprising the chirp-type signal; and

correlating the broadcast analog television signal with the correlation reference signal, thereby producing a pseudorange; and

wherein

the location of the user terminal is determined based on the pseudorange and a location of the transmitter of the broadcast analog television signal.

30. The method of claim 29, wherein the chirp-type signal is a vertical interval test signal.

31. The method of claim 29, wherein the chirp-type signal is ghost canceling reference signal A, ghost canceling reference signal B, or ghost canceling reference signal C.

32. The method of claim 29, further comprising:

determining the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.

33. The method of claim 32, further comprising:

determining the location of the user terminal based on the pseudorange, a pseudorange computed based on a broadcast digital television signal, and the locations of the transmitters of the broadcast analog television signal and the broadcast digital television signal.

34. The method of claim 29, further comprising:

identifying the peak of the result of the correlating, thereby producing the pseudorange.

35. The method of claim 29, wherein the position of the user terminal is determined by adjusting the:

pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.

36. The method of claim 29, further comprising:

determining a further pseudorange based on a further broadcast analog television signal; and

projecting the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.

37. The method of claim 29, further comprising:

tracking the chirp-type signal using a time-gated delay-lock loop.

38. An apparatus for determining the position of a user terminal, comprising:

means for generating a correlation reference signal based on known characteristics of a chirp-type signal present in a broadcast analog television signal;

means for receiving, at the user terminal, a broadcast analog television signal comprising the chirp-type signal; and

means for correlating the broadcast analog television signal with the correlation reference signal, thereby producing a pseudorange; and

wherein

the location of the user terminal is determined based on the pseudorange and a location of the transmitter of the broadcast analog television signal.

39. The apparatus of claim 38, wherein the chirp-type signal is a vertical interval test signal.

40. The method of claim 38, wherein the chirp-type signal is ghost canceling reference signal A, ghost canceling reference signal B, or ghost canceling reference signal C.

41. The apparatus of claim 38, further comprising:

means for determining the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.

42. The apparatus of claim 41, further comprising:

determining the location of the user terminal based on the pseudorange, a pseudorange computed based on a broadcast digital television signal, and the locations of the transmitters of the broadcast analog television signal and the broadcast digital television signal.

43. The apparatus of claim 38, further comprising:

means for identifying the peak of the result of the correlating, thereby producing the pseudorange.

44. The apparatus of claim 38, wherein the position of the user terminal is determined by adjusting the pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.

45. The apparatus of claim 38, further comprising:

means for determining a further pseudorange based on a further broadcast analog television signal; and

means for projecting the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.

46. The apparatus of claim 38, further comprising:

means for tracking the chirp-type signal using a time-gated delay-lock loop.

47. An apparatus for determining the position of a user terminal, comprising:

a signal generator to generate a correlation reference signal based on known characteristics of a chirp-type signal present in a broadcast analog television signal;

a receiver to receive, at the user terminal, a broadcast analog television signal comprising the chirp-type signal; and

a correlator to correlate the broadcast analog television signal with the correlation reference signal, thereby producing a pseudorange; and

wherein

the location of the user terminal is determined based on the pseudorange and a location of the transmitter of the broadcast analog television signal.

48. The apparatus of claim 47, wherein the chirp-type signal is a vertical interval test signal.

49. The method of claim 47, wherein the chirp-type signal is ghost canceling reference signal A, ghost canceling reference signal B, or ghost canceling reference signal C.

50. The apparatus of claim 47, further comprising:

a processor to determine the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.

51. The apparatus of claim 50, wherein the processor determines the location of the user terminal based on the pseudorange, a pseudorange computed based on a broadcast digital television signal, and the locations of the transmitters of the broadcast analog television signal and the broadcast digital television signal.

52. The apparatus of claim 47, wherein the processor identifies the peak of the result of the correlating, thereby producing the pseudorange.

53. The apparatus of claim 47, wherein the position of the user terminal is determined by adjusting the pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.

54. The apparatus of claim 47, wherein the processor:

determines a further pseudorange based on a further broadcast analog television signal; and

projects the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.

55. The apparatus of claim 47, further comprising:

a time-gated delay-lock loop to track the chirp-type signal.

56. Computer-readable media embodying instructions executable by a computer to perform a method for determining the position of a user terminal, the method comprising:

generating a correlation reference signal based on known characteristics of a chirp-type signal present in a broadcast analog television signal;

receiving, at the user terminal, a broadcast analog television signal comprising the chirp-type signal; and

correlating the broadcast analog television signal with the correlation reference signal, thereby producing a pseudorange; and

wherein

the location of the user terminal is determined based on the pseudorange and a location of the transmitter of the broadcast analog television signal.

57. The media of claim 56, wherein the chirp-type signal is a vertical interval test signal.

58. The method of claim 56, wherein the chirp-type signal is ghost canceling reference signal A, ghost canceling reference signal B, or ghost canceling reference signal C.

59. The media of claim 56, wherein the method further comprises:

determining the location of the user terminal based on the pseudorange and the location of the transmitter of the broadcast analog television signal.

60. The media of claim 59, wherein the method further comprises:

determining the location of the user terminal based on the pseudorange, a pseudorange computed based on a broadcast digital television signal, and the locations of the transmitters of the broadcast analog television signal and the broadcast digital television signal.

61. The media of claim 56, wherein the method further comprises:

identifying the peak of the result of the correlating, thereby producing the pseudorange.

62. The media of claim 56, wherein the position of the user terminal is determined by adjusting the pseudoranges based on a difference between a transmitter clock at the transmitter of the broadcast analog television signal and a known time reference, and determining the position of the user terminal based on the adjusted pseudorange and the location of the TV transmitter.

63. The media of claim 56, wherein the method further comprises:

determining a further pseudorange based on a further broadcast analog television signal; and

projecting the pseudorange and the further pseudorange to an instant of time, thereby eliminating any first order term in the clock of the user terminal.

64. The media of claim 56, wherein the method further comprises:

tracking the chirp-type signal using a time-gated delay-lock loop.