Patents by Inventor Adolf DSouza

Adolf DSouza has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7092036
    Abstract: An equalizer (34) and a prefilter (1) used in conjunction with a comb filter (2) in a High Definition Television (HDTV) system. The prefilter (1) may be placed before the comb filter (2), or alternatively may be placed after the comb filter. Further, the method may be enhanced by estimating the filter tap when the prefilter (1) is placed after the comb filter (2). The equalizer (34) produces a fifteen level output from the eight level Vestigial Sideband (VSB) input without limiting the amplitude at symbol 12 to a relatively small value, such as ?20 dB. Three specific methods of increasing the permissible amplitude at symbol 12 are presented which permit tap 12 amplitudes as high as ?6 dB.
    Type: Grant
    Filed: March 14, 2003
    Date of Patent: August 15, 2006
    Assignee: Thomson Licensing
    Inventor: Adolf DSouza
  • Patent number: 6894728
    Abstract: A method and apparatus for equalizing a signal containing high definition television information in the presence of co-channel NTSC interference employs an equalizer having feed forward and decision feedback filters. A comb filter is inserted ahead of the equalizer when NTSC co-channel interference is present. A selected tap of the decision feedback filter is set to a zero value when the signal is being equalized during an intitial blind operating mode. The decision feedback filter taps are updated afterwards, in a decision-directed operating mode.
    Type: Grant
    Filed: March 20, 2002
    Date of Patent: May 17, 2005
    Assignee: Thomas Licensing S.A.
    Inventor: Adolf DSouza
  • Publication number: 20030193617
    Abstract: An equalizer (34) and a prefilter (1) used in conjunction with a comb filter (2) in a High Definition Television (HDTV) system. The prefilter (1) may be placed before the comb filter (2), or alternatively may be placed after the comb filter. Further, the method may be enhanced by estimating the filter tap when the prefilter (1) is placed after the comb filter (2). The equalizer (34) produces a fifteen level output from the eight level Vestigial Sideband (VSB) input without limiting the amplitude at symbol 12 to a relatively small value, such as −20 dB. Three specific methods of increasing the permissible amplitude at symbol 12 are presented which permit tap 12 amplitudes as high as −6 dB.
    Type: Application
    Filed: March 14, 2003
    Publication date: October 16, 2003
    Inventor: Adolf DSouza
  • Publication number: 20030001974
    Abstract: A method and apparatus for equalizing a signal containing high definition television information in the presence of co-channel NTSC interference employs an equalizer having feed forward and decision feedback filters. A comb filter is inserted ahead of the equalizer when NTSC co-channel interference is present. A selected tap of the decision feedback filter is set to a zero value when the signal is being equalized during an intitial blind operating mode. The decision feedback filter taps are updated afterwards, in a decision-directed operating mode.
    Type: Application
    Filed: March 20, 2002
    Publication date: January 2, 2003
    Inventor: Adolf DSouza
  • Patent number: 5517213
    Abstract: A blind equalization process (200) for an adaptive equalizer including a plurality of taps, each having a corresponding coefficient, is disclosed which comprises the following steps. Blind equalization (204) is performed on a subset of the coefficients in the adaptive equalizer. Then, if the coefficients have converged (206), a decision directed adaptive equalization process (220) is initiated.
    Type: Grant
    Filed: September 29, 1994
    Date of Patent: May 14, 1996
    Assignee: Thomson Consumer Electronics, Inc.
    Inventors: Bhavesh B. Bhatt, Adolf Dsouza