Time-gated delay lock loop tracking of digital television signals
First Claim
1. A method for use in determining the position of a user terminal, comprising:
- receiving at the user terminal a digital television (DTV) broadcast signal transmitted by a DTV transmitter;
tracking a periodic component of the DTV signal using a delay-lock loop (DLL), including selecting an observation interval based on the timing of the periodic component, and turning on a portion of the DLL during the observation interval, and turning the portion off otherwise; and
determining a pseudo-range between the user terminal and the DTV transmitter based on the DTV broadcast signal; and
wherein the position of the user terminal is determined based on the pseudo-range and a location of the DTV transmitter.
4 Assignments
0 Petitions
Accused Products
Abstract
A computer program product, apparatus, and method for use in determining the position of a user terminal includes receiving at the user terminal a digital television (DTV) broadcast signal transmitted by a DTV transmitter; tracking a periodic component of the DTV signal using a delay-lock loop (DLL), including selecting an observation interval based on the timing of the periodic component, and turning on a portion of the DLL during the observation interval, and turning the portion off otherwise; and determining a pseudo-range between the user terminal and the DTV transmitter based on the DTV broadcast signal; and wherein the position of the user terminal is determined based on the pseudo-range and a location of the DTV transmitter.
84 Citations
52 Claims
-
1. A method for use in determining the position of a user terminal, comprising:
-
receiving at the user terminal a digital television (DTV) broadcast signal transmitted by a DTV transmitter;
tracking a periodic component of the DTV signal using a delay-lock loop (DLL), including selecting an observation interval based on the timing of the periodic component, and turning on a portion of the DLL during the observation interval, and turning the portion off otherwise; and
determining a pseudo-range between the user terminal and the DTV transmitter based on the DTV broadcast signal; and
whereinthe position of the user terminal is determined based on the pseudo-range and a location of the DTV transmitter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
determining the position of the user terminal based on the pseudo-range and the location of the DTV transmitter.
-
-
3. The method of claim 2, wherein determining a position of the user terminal comprises:
-
adjusting the pseudo-range based on a difference between a transmitter clock at the DTV transmitter and a known time reference; and
determining the position of the user terminal based on the adjusted pseudo-range and the location of the DTV transmitter.
-
-
4. The method of claim 1, wherein the DTV broadcast signal is an American Television Standards Committee (ATSC) DTV signal, and the pseudo-range is determined based on a known digital sequence in the ATSC frame.
-
5. The method of claim 4, wherein the known digital sequence is a synchronization code.
-
6. The method of claim 5, wherein the synchronization code is a Field Synchronization Segment within an ATSC data frame.
-
7. The method of claim 5, wherein the synchronization code is a Synchronization Segment within a Data Segment within an ATSC data frame.
-
8. The method of claim 1, wherein determining a position of the user terminal comprises:
-
determining an offset between a local time reference in the user terminal and a master time reference; and
determining the position of the user terminal based on the pseudo-range, the location of the DTV transmitter, and the offset.
-
-
9. The method of claim 1, wherein determining a pseudo-range comprises:
correlating the DTV signal with a signal generated by the user terminal as the DTV signal is received to produce the pseudo-range.
-
10. The method of claim 1, further comprising:
-
tracking the pilot signal of the DTV signal using a phase-lock loop; and
whereintracking the component of the DTV signal is based on the tracking of the pilot signal.
-
-
11. The method of claim 1, further comprising:
transmitting the pseudo-range to a location server configured to determine a position of the user terminal based on the pseudo-range and a location of the DTV transmitter.
-
12. The method of claim 1, wherein the position of the user terminal is determined by adjusting the pseudorange 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 method of claim 1, further comprising:
-
determining a further pseudorange based on a further DTV 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.
-
-
14. Computer-readable media embodying instructions executable by a computer to perform a method for use in determining the position of a user terminal, the method comprising:
-
receiving at the user terminal a digital television (DTV) broadcast signal transmitted by a DTV transmitter;
tracking a periodic component of the DTV signal using a delay-lock loop (DLL), including selecting an observation interval based on the timing of the periodic component, and turning on a portion of the DLL during the observation interval, and turning the portion off otherwise; and
determining a pseudo-range between the user terminal and the DTV transmitter based on the DTV broadcast signal; and
whereinthe position of the user terminal is determined based on the pseudo-range and a location of the DTV transmitter. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
determining the position of the user terminal based on the pseudo-range and the location of the DTV transmitter.
-
-
16. The media of claim 15, wherein determining a position of the user terminal comprises:
-
adjusting the pseudo-range based on a difference between a transmitter clock at the DTV transmitter and a known time reference; and
determining the position of the user terminal based on the adjusted pseudo-range and the location of the DTV transmitter.
-
-
17. The media of claim 14, wherein the DTV broadcast signal is an American Television Standards Committee (ATSC) DTV signal, and the pseudo-range is determined based on a known digital sequence in the ATSC frame.
-
18. The media of claim 17, wherein the known digital sequence is a synchronization code.
-
19. The media of claim 18, wherein the synchronization code is a Field Synchronization Segment within an ATSC data frame.
-
20. The media of claim 18, wherein the synchronization code is a Synchronization Segment within a Data Segment within an ATSC data frame.
-
21. The media of claim 14, wherein determining a position of the user terminal comprises:
-
determining an offset between a local time reference in the user terminal and a master time reference; and
determining the position of the user terminal based on the pseudo-range, the location of the DTV transmitter, and the offset.
-
-
22. The media of claim 14, wherein determining a pseudo-range comprises:
correlating the DTV signal with a signal generated by the user terminal as the DTV signal is received to produce the pseudo-range.
-
23. The media of claim 14, wherein the method further comprises:
-
tracking the pilot signal of the DTV signal using a phase-lock loop; and
whereintracking the component of the DTV signal is based on the tracking of the pilot signal.
-
-
24. The media of claim 14, wherein the method further comprises:
transmitting the pseudo-range to a location server configured to determine a position of the user terminal based on the pseudo-range and a location of the DTV transmitter.
-
25. The media of claim 14, wherein the position of the user terminal is determined by adjusting the pseudorange 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.
-
26. The media of claim 14, wherein the method further comprises:
-
determining a further pseudorange based on a further DTV 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.
-
-
27. An apparatus for use in determining the position of a user terminal, comprising:
-
means for receiving at the user terminal a digital television (DTV) broadcast signal transmitted by a DTV transmitter;
means for tracking a periodic component of the DTV signal using a delay-lock loop (DLL), including means for selecting an observation interval based on the timing of the periodic component, and means for turning on a portion of the DLL during the observation interval, and turning the portion off otherwise; and
means for determining a pseudo-range between the user terminal and the DTV transmitter based on the DTV broadcast signal; and
whereinthe position of the user terminal is determined based on the pseudo-range and a location of the DTV transmitter. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
means for determining the position of the user terminal based on the pseudo-range and the location of the DTV transmitter.
-
-
29. The apparatus of claim 28, wherein means for determining a position of the user terminal comprises:
-
means for adjusting the pseudo-range based on a difference between a transmitter clock at the DTV transmitter and a known time reference; and
means for determining the position of the user terminal based on the adjusted pseudo-range and the location of the DTV transmitter.
-
-
30. The apparatus of claim 27, wherein the DTV broadcast signal is an American Television Standards Committee (ATSC) DTV signal, and the pseudo-range is determined based on a known digital sequence in the ATSC frame.
-
31. The apparatus of claim 30, wherein the known digital sequence is a synchronization code.
-
32. The apparatus of claim 31, wherein the synchronization code is a Field Synchronization Segment within an ATSC data frame.
-
33. The apparatus of claim 31, wherein the synchronization code is a Synchronization Segment within a Data Segment within an ATSC data frame.
-
34. The apparatus of claim 27, wherein means for determining a position of the user terminal comprises:
-
means for determining an offset between a local time reference in the user terminal and a master time reference; and
means for determining the position of the user terminal based on the pseudo-range, the location of the DTV transmitter, and the offset.
-
-
35. The apparatus of claim 27, wherein means for determining a pseudo-range comprises:
means for correlating the DTV signal with a signal generated by the user terminal as the DTV signal is received to produce the pseudo-range.
-
36. The apparatus of claim 27, further comprising:
-
means for tracking the pilot signal of the DTV signal using a phase-lock loop; and
whereinmeans for tracking the component of the DTV signal is based on the tracking of the pilot signal.
-
-
37. The apparatus of claim 27, further comprising:
means for transmitting the pseudo-range to a location server configured to determine a position of the user terminal based on the pseudo-range and a location of the DTV transmitter.
-
38. The apparatus of claim 27, wherein the position of the user terminal is determined by adjusting the pseudorange 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.
-
39. The apparatus of claim 27, further comprising:
-
means for determining a further pseudorange based on a further DTV 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.
-
-
40. An apparatus for use in determining the position of a user terminal, comprising:
-
an antenna to receive at the user terminal a digital television (DTV) broadcast signal transmitted by a DTV transmitter;
a receiver to track a periodic component of the DTV signal using a delay-lock loop (DLL), including a controller to select an observation interval based on the timing of the periodic component, and turn on a portion of the DLL during the observation interval, and turn the portion off otherwise; and
a processor to determine a pseudo-range between the user terminal and the DTV transmitter based on the DTV broadcast signal; and
whereinthe position of the user terminal is determined based on the pseudo-range and a location of the DTV transmitter. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
adjusts the pseudo-range based on a difference between a transmitter clock at the DTV transmitter and a known time reference; and
determines the position of the user terminal based on the adjusted pseudo-range and the location of the DTV transmitter.
-
-
43. The apparatus of claim 40, wherein the DTV broadcast signal is an American Television Standards Committee (ATSC) DTV signal, and the pseudo-range is determined based on a known digital sequence in the ATSC frame.
-
44. The apparatus of claim 43, wherein the known digital sequence is a synchronization code.
-
45. The apparatus of claim 44, wherein the synchronization code is a Field Synchronization Segment within an ATSC data frame.
-
46. The apparatus of claim 44, wherein the synchronization code is a Synchronization Segment within a Data Segment within an ATSC data frame.
-
47. The apparatus of claim 40, wherein the processor:
-
determines an offset between a local time reference in the user terminal and a master time reference; and
determines the position of the user terminal based on the pseudo-range, the location of the DTV transmitter, and the offset.
-
-
48. The apparatus of claim 40, wherein the processor correlates the DTV signal with a signal generated by the user terminal as the DTV signal is received to produce the pseudo-range.
-
49. The apparatus of claim 40, further comprising:
-
a phase-lock loop to track the pilot signal of the DTV signal; and
whereintracking the component of the DTV signal is based on the tracking of the pilot signal.
-
-
50. The apparatus of claim 40, further comprising:
a transmitter to transmit the pseudo-range to a location server configured to determine a position of the user terminal based on the pseudo-range and a location of the DTV transmitter.
-
51. The apparatus of claim 40, wherein the position of the user terminal is determined by adjusting the pseudorange 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.
-
52. The apparatus of claim 40, wherein the processor:
-
determines a further pseudorange based on a further DTV 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.
-
Specification