Detector for digital television signal

• US 20070157269A1
• Filed: 01/04/2006
• Published: 07/05/2007
• Est. Priority Date: 01/04/2006
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Visotsky, Eugene, Peterson, Roger, Kuffner, Stephen
• Granted Patent: US 7,516,471 B2
• Time in Patent Office: Days
• US Class Current: 725/100
• CPC Class Codes: H04H 60/43 for identifying broadcast channels
• CPC Class Codes: H04H 60/65 for using the result on users' side

Abstract

A DTV signal detector detects DTV signals received by a receiver on a selected DTV channel in a Digital Television System. The DTV detector includes a first DTV signal detector that detects a first characteristic of the received DTV signals, and a second DTV signal detector that detects at least a second characteristic of the received DTV signals. A controller responds to the first DTV signal detector and the second DTV signal detector to control a selection of the DTV channel being selected by the receiver. The receiver can be synthesized to select from more than one DTV channel.

Claims

1. A communication device for use in a digital television (DTV) system, comprising:

a receiver that receives digital television (DTV) signals on a selected DTV channel;

a base band processor that processes the received DTV signals;

a DTV signal detector that detects the DTV signals; and

a controller, responsive to the DTV signal detector, to control a selection of the DTV channel being selected by said receiver, wherein

said DTV signal detector comprises;

a first DTV signal detector for detecting a first characteristic of the received DTV signals, and

a second DTV signal detector for detecting at least a second

characteristic of the received DTV signals,

said controller being responsive to said first DTV signal detector and said second DTV signal detector for controlling the selection of the DTV channel being selected by said synthesized receiver.

2. The communication device according to claim 1, wherein said first DTV detector is a pilot signal detector that detects the presence of a pilot signal in the DTV signal.

3. The communication device according to claim 1, wherein said second DTV detector is a delay-multiply detector that detects the presence of a baud-rate spectral line in the DTV signal.

4. The communication device according to claim 1, wherein said receiver is a synthesized receiver.

5. The communication device according to claim 4, wherein said controller controls the selection of a new DTV channel by said synthesized receiver when said DTV detector detects that the DTV signal is absent.

6. The communication device according to claim 4, wherein said controller maintains the selection of the current DTV channel by said synthesized receiver when said DTV detector detects that the DTV signal is present.

7. The communication device according to claim 1 further comprising a synthesized transmitter to enable transmission of information from the communication device on the DTV channel.

8. A DTV detector, comprising:

a first DTV signal detector coupled to a receiver for detecting a first characteristic of a received DTV signal and generating in response thereto a first decision output there from; and

a second DTV signal detector also coupled to said receiver for detecting at least a second characteristic of the received DTV signals and generating in response thereto a second decision output there from;

a logical decision element coupled to said first DTV signal detector and said second DTV signal detector, and responsive to the first decision output and the second decision output for determining that a DTV signal is being received.

9. The DTV detector according to claim 8, wherein said first DTV detector is a pilot signal detector that detects presence of a pilot signal in the DTV signal.

10. The DTV detector according to claim 8, wherein said second DTV detector is a delay-multiply detector that detects presence of a baud-rate spectral line in the DTV signal.

11. The DTV detector according to claim 8, wherein said receiver is a synthesized receiver, and wherein a controller controls the selection of a new DTV channel by said synthesized receiver when said DTV detector detects that the DTV signal is absent.

12. The DTV detector according to claim 8, wherein said receiver is a synthesized receiver, and wherein a controller maintains the selection of the current DTV channel by said synthesized receiver when said DTV detector detects that the DTV signal is present.

13. A DTV detector, comprising:

a first DTV signal detector coupled to a receiver for detecting a first characteristic of a received DTV signal and generating in response thereto a first decision output there from;

a controller that is responsive to said first DTV signal detector for enabling operation of a second DTV detector;

said second DTV signal detector also coupled to said receiver for detecting at least a second characteristic of the received DTV signals and generating in response thereto a second decision output there from;

a logical decision element coupled to said first DTV signal detector and said second DTV signal detector, and responsive to the first decision output and the second decision output for determining that a DTV signal is being received.

14. The DTV detector according to claim 13, wherein the DTV detector further comprises

a threshold detector, coupled to said first DTV detector, and responsive to the output thereof, to detect when a level of the DTV signal being received equals or exceeds a predetermined threshold DTV signal value,

said threshold detector being coupled to said logical decision element for controlling a selection the first decision output and the second decision output for determining that a DTV signal is being received.

15. The DTV detector according to claim 13, wherein said first DTV detector is a pilot signal detector that detects presence of a pilot signal in the DTV signal.

16. The DTV detector according to claim 13, wherein said second DTV detector is a delay-multiply detector that detects presence of a baud-rate spectral line in the DTV signal.

17. The DTV detector according to claim 13, wherein said receiver is a synthesized receiver, and wherein a controller controls the selection of a new DTV channel by said synthesized receiver when said DTV detector detects that the DTV signal is absent.

18. The DTV detector according to claim 13, wherein said receiver is a synthesized receiver, and wherein a controller maintains the selection of the current DTV channel by said synthesized receiver when said DTV detector detects that the DTV signal is present.

19. A wide regional area network, comprising:

a geographic area having one or more active DTV channels and one or more inactive DTV channels;

a communication device that can receive information transmitted on said one or more active DTV channels and one or more inactive DTV channels,

said communication device comprising;

a receiver that receives digital television (DTV) signals on a selected DTV channel;

a base band processor that processes the received DTV signals;

a DTV signal detector that detects the DTV signals; and

a controller, responsive to the DTV signal detector, to control a selection of the DTV channel being selected by said receiver, wherein

said DTV signal detector comprises

a first DTV signal detector for detecting a first characteristic of the received DTV signals, and

a second DTV signal detector for detecting at least a second characteristic of the received DTV signals,

said controller being responsive to said first DTV signal detector and said second DTV signal detector for controlling the selection of the DTV channel being selected by said receiver.

20. The wide regional area network according to claim 19, wherein said first DTV detector is a pilot signal detector that detects presence of a pilot signal in the DTV signal.

21. The wide regional area network according to claim 19, wherein said second DTV detector is a delay-multiply detector that detects presence of a baud-rate spectral line in the DTV signal.

22. The wide regional area network according to claim 19, wherein said receiver is a synthesized receiver, and wherein said controller controls the selection of a new DTV channel by said synthesized receiver when said DTV detector detects that the DTV signal is absent.

23. The wide regional area network according to claim 22, wherein said controller maintains the selection of the current DTV channel by said synthesized receiver when said DTV detector detects that the DTV signal is present.

24. The wide regional area network according to claim 22, wherein the communication device further comprises a synthesized transmitter to enable transmission of information from the communication device on the DTV channel.