Method and apparatus for the transmission and reception of a multicarrier digital television signal

• US 5,282,019 A
• Filed: 04/29/1992
• Issued: 01/25/1994
• Est. Priority Date: 10/03/1988
• Status: Expired due to Fees

• Current Assignee: Alan P. Cavallerano, Aldo G. Cugnini, Carlo Basile, David A. Bryan, Faramarz Azadegan, Mikhail Tsinberg, Yo-Sung Ho
• Original Assignee: Alan P. Cavallerano, Aldo G. Cugnini, Carlo Basile, David A. Bryan, Faramarz Azadegan, Mikhail Tsinberg, Yo-Sung Ho
• Inventors: Cugnini, Aldo G., Basile, Carlo, Tsinberg, Mikhail, Bryan, David A., Ho, Yo-Sung, Cavallerano, Alan P., Azadegan, Faramarz
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): Powell, Mark R.
• Application Number:
  US07/875,491
• Time in Patent Office: 636 Days
• Field of Search: 358/12, 358/141, 358/142, 358/133, 358/15, 370/118, 370/109
• US Class Current: 348/488
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04N 11/24 High-definition television systems
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 5/211 Ghost signal cancellation H04N23/81 takes precedence
• CPC Class Codes: H04N 5/44 Receiver circuitry for the reception of television signals according to analogue transmission standards H04N5/14 takes precedence
• CPC Class Codes: H04N 5/602 for digital sound signals
• CPC Class Codes: H04N 7/063 Simultaneous transmission of separate parts of one picture
• 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 method and apparatus for encoding a television source signal having a first bandwidth, into a frequency multiplexed signal having a narrower bandwidth and comprising a plurality of subcarriers modulated with digital information. Each of said subcarriers has an amplitude, bandwidth and coding characteristic which reflects the relative importance of the digital information provided thereby. The frequency multiplexed signal is suitable for use in a broadcasting environment wherein a conventional television signal is also used and wherein said subcarriers are disposed in frequency, in positions which are least likely to result in interference to or from said conventional signal. The invention also includes a receiver for decoding the frequency multiplexed signal and for providing a high definition display.

Claims

1. A method for forming a frequency multiplexed television signal comprising the steps of:

a) coding a television source signal having a first bandwidth into a plurality of digital data streams;

b) processing each of said digital data streams so as to distribute information provided by each of them as a plurality of modulated subcarriers each having respective bandwidth, amplitude and coding characteristics, said subcarriers forming a frequency multiplexed signal having a second bandwidth which is more narrow than said first bandwidth; and

wherein a first subcarrier is modulated with information having a first priority and a second subcarrier is modulated with information having a second priority.

2. The method as claimed in claim 1, wherein said modulated subcarriers are formed by quadrature amplitude modulation.

3. The method as claimed in claim 1, wherein each of said modulated subcarriers distributes its respective information at respective signaling rates.

4. The method of claim 1, wherein said information provided by each of said digital data streams determines which of said modulated subcarriers distributes said respective information.

5. The method of claim 1, wherein said second priority is higher than said first priority.

6. An apparatus for forming a frequency multiplexed television signal comprising:

a) means for coding a television source signal having a first bandwidth, into a plurality of digital data streams; and

b) means coupled to said source coding means for processing each of said digital data streams so as to distribute information provided by each of them as a plurality of modulated subcarriers each having respective bandwidth, amplitude and coding characteristics, said subcarriers forming a frequency multiplexed signal having a bandwidth which is more narrow than said first bandwidth; and

wherein a first subcarrier is modulated with information having a first priority and a second subcarrier is modulated with information having a second priority.

7. The apparatus of claim 6, wherein said information provided by each of said digital data streams determines which of said modulated subcarriers distributes said respective information.

8. A receiver for providing a high definition television (HDTV) display, for use in a television transmission system wherein a television source signal having a first bandwidth, is encoded into a plurality of digital data streams and wherein each of said data streams is process so that information provided by each of them is distributed as a plurality of modulated subcarriers each having respective bandwidth, amplitude and coding characteristics, and wherein said modulated subcarriers form a frequency multiplexed television signal having a bandwidth which is more narrow than said first bandwidth, and wherein a first subcarrier is modulated with information having a first priority and a second subcarrier is modulated with information having a second priority, said receiver comprising:

a) means for demodulating said frequency multiplexed signal so as to recover said modulated subcarriers; and

b) means for decoding from said modulated subcarriers, a plurality of television signal components and for providing said components for display.

9. An apparatus for forming a frequency multiplexed television signal suitable for use in a broadcasting environment wherein a conventional television signal comprising a plurality of conventional subcarriers having respective frequency locations within said conventional television signal is also used, said apparatus comprising:

a) means for coding a television source signal having a first bandwidth, into a plurality of digital data streams;

b) means coupled to said source coding means, for processing each of said digital data streams so as to distribute information provided by each of them, as a plurality of modulated subcarriers each having respective bandwidth, amplitude and coding characteristics, said information provided by each of said digital data streams determining which of said modulated subcarriers distributes said respective information; and

c) means for selecting the frequencies of said modulated subcarriers so as to place them in respective frequency locations within said frequency multiplexed signal so as to be least likely to cause interference to and suffer interference from at least one of said plurality of conventional subcarriers of said conventional television signal.

10. An apparatus for providing a television display from the frequency multiplexed television signal of claim 9, comprising:

a) means for demodulating said frequency multiplexed signal so as to recover said modulated subcarriers; and

b) means for decoding from said modulated subcarriers, a plurality of television signal components and for providing said components for display.

11. The apparatus of claim 9, wherein said plurality of conventional subcarriers comprises a picture subcarrier.

12. The apparatus of claim 9, wherein said plurality of conventional subcarriers comprises a color subcarrier.

13. The apparatus of claim 9, wherein said plurality of conventional subcarriers comprises a sound subcarrier.