Use of wideband DTV overlay signals for brevity signaling and public safety

• US 6,498,627 B1
• Filed: 10/21/1999
• Issued: 12/24/2002
• Est. Priority Date: 10/21/1999
• Status: Expired due to Term

• Current Assignee: NBC Universal Media LLC (Comcast Corporation)
• Original Assignee: General Electric Company
• Inventors: Hershey, John Erik, Grabb, Mark Lewis, Welles, Kenneth Brakeley II
• Primary Examiner(s): Miller, John
• Assistant Examiner(s): NATNAEL, PAULOS M
• Application Number:
  US09/422,441
• Time in Patent Office: 1,160 Days
• Field of Search: 348/725, 348/729, 348/614, 348/611, 348/607, 375/260, 375/340, 375/346, 375/285, 370/526-528, 370/493-495, 370/332-333, 725/33
• US Class Current: 348/725
• CPC Class Codes: H04L 27/28 with simultaneous transmission of different frequencies each representing one code element
• CPC Class Codes: H04N 21/434 Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream demultiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/4432 Powering on the client, e.g. bootstrap loading using setup parameters being stored locally or received from the server resetting in general G06F1/14; program loading or initiating in general G06F9/445; bootstrapping in general G06F9/4401; secure boots of computer platforms G06F21/57
• CPC Class Codes: H04N 21/478 Supplemental services, e.g. displaying phone caller identification, shopping application
• CPC Class Codes: H04N 21/814 comprising emergency warnings arrangements specially adapted for emergency or urgency in broadcast systems H04H20/59; arrangements for providing alarms, notifications, alerts to substation in data switching networks H04L12/1895
• CPC Class Codes: H04N 21/8146 involving graphical data, e.g. 3D object, 2D graphics
• CPC Class Codes: H04N 5/211 Ghost signal cancellation H04N23/81 takes precedence
• CPC Class Codes: H04N 7/08 Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band , e.g. by time division H04N7/007 takes precedence

Abstract

A brevity signaling module for a digital television (DTV) receiver enables the reception of emergency broadcast messages. The overlay signal received at the receiver front end is squared in a squaring loop, producing spectral lines at DC and twice the overlay signal frequency, or 2ω, where ω=2πf and f is the center frequency of the overlay signal. The squared signal is passed through a narrow band filter having a bandwidth sufficient to pass a spectrum containing a plurality of tones 2ω, 2ω₁, 2ω₂, . . . , 2ω_n, where 2ω₁, 2₂, . . . , 2ω_n are different frequency tones assigned to different auxiliary functions. The detected tone is used by a control module to determine whether normal multipath processing should be performed or whether this processing should be suppressed and auxiliary functions performed, including turning on the DTV receiver power in order that an emergency broadcast message might be conveyed to persons in the vicinity of the DTV receiver.

Claims

1. A brevity signaling module for a digital television (DTV) receiver which is equipped to receive and process a wideband overlay signal used for multipath processing, the brevity signaling module being adapted to enable reception of emergency broadcast messages and comprising:

a receiver front end for receiving and detecting the wideband overlay signal;

a squaring loop for squaring the detected wideband overlay signal detected by the receiver front end to generate a spectral line at 2ω

, where ω

=2π

f and f is the overlay signal center frequency, said squaring loop including a narrow band filter having a bandwidth sufficient to pass a spectrum containing a plurality of tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n, where 2ω

₁, 2ω

₂, . . . , 2ω

_n are different frequency tones assigned to different auxiliary functions;

tone identification logic to detect, in the spectrum produced by said filter, a transmitted tone corresponding to one of the tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n; and

a control module responsive to the tone identification logic to determine whether normal multipath processing should be performed or whether multipath processing should be suppressed and auxiliary functions performed.

2. The brevity signaling module recited in claim 1, wherein one of said auxiliary functions is power control and further comprising a DTV power supply responsive to said control module for turning on the DTV receiver power in order that an emergency broadcast message might be conveyed to persons in the vicinity of the DTV receiver.

3. The brevity signaling module recited in claim 1, further comprising a command port responsive to said control module for signaling an emergency message.

4. The brevity signaling module recited in claim 3, including, coupled to said command port, at least one of the group consisting of an automatic telephone dialer, a pager, and an Internet connection.

5. The brevity signaling module recited in claim 1, wherein said tone identification logic includes a plurality of narrow band filters for passing a respective one of the frequency tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n.

6. The brevity signaling module recited in claim 1 wherein said tone identification logic includes Fourier transform logic to generate a plurality of frequency bins corresponding to the frequency tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n, respectively.

7. A receiver comprising:

a receiver front end for receiving and detecting a wideband overlay signal;

a squaring loop for squaring the detected wideband overlay signal to generate a spectral line at 2ω

, where ω

=2π

f and f is the overlay signal center frequency;

a narrow band filter having a bandwidth sufficient to pass a spectrum containing a plurality of tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n, where 2ω

₁, 2ω

₂, . . . , 2ω

_n are different frequency tones assigned to different auxiliary functions;

tone identification logic to detect, in the spectrum produced by said filter, a transmitted tone corresponding to the center frequency of the overlay signal; and

a control module responsive to the tone identification logic to determine whether an auxiliary function should be invoked.

8. The receiver recited in claim 7, further comprising a command port responsive to said control module for signaling an emergency message.

9. The receiver recited in claim 8 including, coupled to said command port, at least one of the group consisting of an automatic telephone dialer, a pager, and an Internet connection.

10. The receiver recited in claim 7, wherein one of said auxiliary functions is control of power and further comprising a power supply responsive to said control module for turning on the receiver by supplying power thereto in order that a broadcast message might be conveyed to persons in the vicinity of the receiver.

11. The receiver recited in claim 7 wherein said tone identification logic includes a plurality of narrow band filters for passing a respective one of the frequency tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n.

12. The receiver recited in claim 7 wherein said tone identification logic includes Fourier transform logic to generate a plurality of frequency bins corresponding to the frequency tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n, respectively.

13. A method of signaling for a digital television (DTV) receiver which is equipped to receive and process a wideband overlay signal used for multipath processing, the method of signaling enabling reception of emergency broadcast messages and comprising the steps of:

receiving and detecting the wideband overlay signal;

squaring the detected wideband overlay signal to generate a spectral line at 2ω

, where ω

=2π

f and f is the overlay signal center frequency;

filtering the squared overlay signal in a narrow band filter having a bandwidth sufficient to pass a spectrum containing a plurality of tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n, where 2ω

₁, 2ω

₂, . . . , 2ω

_n, are different frequency tones assigned to different auxiliary functions;

detecting a transmitted tone corresponding to the tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n; and

determining whether normal multipath processing should be performed or whether multipath processing should be suppressed and auxiliary functions performed.

14. The method of signaling recited in claim 13, further comprising the step of activating an auxiliary signaling device in response to a determination that an emergency message should be transmitted as one of said auxiliary functions.

15. The method of signaling recited in claim 14, wherein the auxiliary signaling device includes at least one of the group consisting of an automatic telephone dialer, a pager, and a modem for connection to the Internet.

16. The method of signaling recited in claim 13, wherein one of said auxiliary functions is control of power and further comprising the step of turning on the DTV receiver power in order that an emergency broadcast message might be conveyed to persons in the vicinity of the DTV receiver.

17. The method of signaling recited in claim 13, wherein the step of detecting a transmitted tone includes the step of filtering the squared overlay signal in a plurality of narrow band filters passing a respective one of the frequency tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n.

18. The method of signaling recited in claim 13, wherein the step of detecting a transmitted tone includes the step of performing a Fourier transform to generate a plurality of frequency bins corresponding to the frequency tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n, respectively.

19. A method of signaling for a receiver which is equipped to receive and process a wideband overlay signal, the method of signaling enabling reception of broadcast messages and comprising the steps of:

receiving and detecting the wideband overlay signal;

squaring the detected wideband overlay signal to generate a spectral line at 2ω

, where ω

=2π

f and f is the overlay signal center frequency;

filtering the squared overlay signal in a narrow band filter having a bandwidth sufficient to pass a spectrum containing a plurality of tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n, where 2ω

₁, 2ω

₂, . . . , 2ω

_n are different frequency tones assigned to different auxiliary functions;

detecting a transmitted tone corresponding to the tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n; and

determining whether auxiliary functions are to be performed.

20. The method of signaling recited in claim 19, further comprising the step of activating an auxiliary signaling device in response to a determination that an emergency message should be transmitted as one of said auxiliary functions.

21. The method of signaling recited in claim 20, wherein the auxiliary signaling device includes at least one of the group consisting of an automatic telephone dialer, a pager, and a modem for connection to the Internet.

22. The method of signaling recited in claim 19, wherein one of said auxiliary functions is control of power and further comprising the step of turning on the receiver power in order that a broadcast message might be conveyed to persons in the vicinity of the receiver.

23. The method of signaling recited in claim 19, wherein the step of detecting a transmitted tone includes the step of filtering the squared overlay signal in a plurality of narrow band filters passing a respective one of the frequency tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n.

24. The method of signaling recited in claim 19, wherein the step of detecting a transmitted tone includes the step of performing a Fourier transform to generate a plurality of frequency bins corresponding to the frequency tones 2ω

, 2ω

₁, 2ω

₂, . . . , 2ω

_n, respectively.