Patents by Inventor Christian Dubuc

Christian Dubuc 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: 8213543
    Abstract: A transmitter (102) generates a first set of data symbols and a first pilot symbol (601) at a first time, and a second set of data symbols and a second pilot symbol (602) at a different, second time. The first (601) and second (602) pilot symbols are each represented by first (701) and second (702) pilot carriers, respectively, located at first (703) and second (704) predetermined sample frequencies, respectively, in a channel bandwidth. For the first pilot symbol (601), the first (701) and second (702) pilot carriers have first and second predetermined values, respectively. For the second pilot symbol (602), the first (701) and second (702) pilot carriers have third and fourth predetermined values, respectively.
    Type: Grant
    Filed: May 10, 2010
    Date of Patent: July 3, 2012
    Assignee: Rockstar Bidco, LP
    Inventors: Christian Dubuc, Daniel Boudreau, William R. Kirkland
  • Patent number: 7869538
    Abstract: A transmitter (102) generates a first set of data symbols and a first pilot symbol (601) at a first time, and a second set of data symbols and a second pilot symbol (602) at a different, second time. The first (601) and second (602) pilot. symbols are each represented by first (701) and second (702) pilot carriers, respectively, located at first (703) and second (704) predetermined sample frequencies, respectively, in a channel bandwidth. For the first pilot symbol (601), the first (701) and second (702) pilot carriers have first and second predetermined values, respectively. For the second pilot symbol (602), the first (701) and second (702) pilot carriers have third and fourth predetermined values, respectively.
    Type: Grant
    Filed: July 23, 2007
    Date of Patent: January 11, 2011
    Assignee: Nortel Networks Limited
    Inventors: Christian Dubuc, Daniel Boudreau, William R. Kirkland
  • Publication number: 20100220825
    Abstract: A transmitter (102) generates a first set of data symbols and a first pilot symbol (601) at a first time, and a second set of data symbols and a second pilot symbol (602) at a different, second time. The first (601) and second (602) pilot symbols are each represented by first (701) and second (702) pilot carriers, respectively, located at first (703) and second (704) predetermined sample frequencies, respectively, in a channel bandwidth. For the first pilot symbol (601), the first (701) and second (702) pilot carriers have first and second predetermined values, respectively. For the second pilot symbol (602), the first (701) and second (702) pilot carriers have third and fourth predetermined values, respectively.
    Type: Application
    Filed: May 10, 2010
    Publication date: September 2, 2010
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: CHRISTIAN DUBUC, DANIEL BOUDREAU, WILLIAM R. KIRKLAND
  • Patent number: 7486735
    Abstract: The present invention divides the available sub-carriers in an OFDM symbol window into N groups of sub-carriers wherein each group will be associated with sub-bands. In one embodiment, the sub-carriers in a group are spread throughout the range of sub-carriers to improve frequency diversity, and the sub-carriers assigned to any one group are separated by a constant offset. The sub-carriers in the group may be offset by an integer power of two. Within each group, sub-bands are defined using frequency hopping patterns among sub-carriers in the group from one OFDM symbol window to another. A pseudo-random pattern may be employed for sub-carrier mapping from one OFDM symbol window to the next to effectively distribute the sub-bands across the selected band of sub-carriers for the group.
    Type: Grant
    Filed: February 26, 2004
    Date of Patent: February 3, 2009
    Assignee: Nortel Networks Limited
    Inventors: Christian Dubuc, Colin Brown, Daniel Boudreau
  • Patent number: 7428270
    Abstract: Disclosed is a unique system and method for recognizing the type of modulation embedded in an unknown complex baseband signal, comprising a receiver section for extracting the complex baseband signal from a modulated signal having a carrier frequency, and comprising an orderly series of signal processing functions for (a) estimating the bandwidth of the unknown signal, (b) removing the out-of-band noise and correcting gross carrier frequency errors, (c) discriminating between constant envelope and irregular envelope signals, (d) estimating and correcting residual carrier frequency errors, (e) classifying a constant envelope signal into one of the following modulation formats: {Continuous Wave (CW), Frequency Modulation (FM), Frequency Shift Keying (FSK)}, and (f) classifying an irregular envelope signal into one of the following modulation formats: {Amplitude Modulation (AM), Double Sideband Suppressed Carrier (DSB-SC), Binary Shift Keying (BPSK), Quaternary Phase Shift Keying (QPSK), ?/4-shifted QPSK, M-ary
    Type: Grant
    Filed: February 15, 2000
    Date of Patent: September 23, 2008
    Inventors: Christian Dubuc, Daniel Boudreau
  • Patent number: 7388847
    Abstract: The present invention provides an improved channel quality indicator indicia for OFDM communication environments. In addition to taking into consideration carrier-to-interference ratios, the present invention also takes into consideration the degree to which the channel response varies among the sub-carriers throughout the OFDM frequency band. The carrier-to-interference ratio and the degree of channel response variation are directly or indirectly used by a base station to select coding and modulation schemes for transmissions from the base station to the mobile terminal reporting these factors. Further, scheduling of data sent to the mobile terminal and other mobile terminals competing for the same channel resources may also be based in part on the carrier-to-interference ratio and the degree to which the channel response varies.
    Type: Grant
    Filed: October 3, 2003
    Date of Patent: June 17, 2008
    Assignee: Nortel Networks Limited
    Inventors: Christian Dubuc, Jason Robert Duggan, Peiying Zhu
  • Patent number: 7356089
    Abstract: A rotation by a phase offset is applied to symbols to be transmitted by one antenna relative to symbols to be transmitted from another antenna in a wireless communication system employing multi-element antennas at the transmitter. Such a phase offset allows the functionality of a MIMO system to be maintained when a MIMO channel degenerates. Advantageously, a MIMO system using the new signal design may provide a level of performance in a rich-scattering environment that is equivalent to a MIMO system using a known signal design. Furthermore, a MIMO system employing embodiments of the present invention may show significantly improvements in robustness over conventional MIMO systems.
    Type: Grant
    Filed: September 5, 2003
    Date of Patent: April 8, 2008
    Assignee: Nortel Networks Limited
    Inventors: Ming Jia, Peiying Zhu, Wen Tong, Christian Dubuc
  • Publication number: 20070263667
    Abstract: A transmitter (102) generates a first set of data symbols and a first pilot symbol (601) at a first time, and a second set of data symbols and a second pilot symbol (602) at a different, second time. The first (601) and second (602) pilot. symbols are each represented by first (701) and second (702) pilot carriers, respectively, located at first (703) and second (704) predetermined sample frequencies, respectively, in a channel bandwidth. For the first pilot symbol (601), the first (701) and second (702) pilot carriers have first and second predetermined values, respectively. For the second pilot symbol (602), the first (701) and second (702) pilot carriers have third and fourth predetermined values, respectively.
    Type: Application
    Filed: July 23, 2007
    Publication date: November 15, 2007
    Inventors: Christian Dubuc, Daniel Boudreau, William Kirkland
  • Patent number: 7251291
    Abstract: A transmitter (102) generates a first set of data symbols and a first pilot symbol (601) at a first time, and a second set of data symbols and a second pilot symbol (602) at a different, second time. The first (601) and second (602) pilot symbols are each represented by first (701) and second (702) pilot carriers, respectively, located at first (703) and second (704) predetermined sample frequencies, respectively, in a channel bandwidth. For the first pilot symbol (601), the first (701) and second (702) pilot carriers have first and second predetermined values, respectively. For the second pilot symbol (602), the first (701) and second (702) pilot carriers have third and fourth predetermined values, respectively.
    Type: Grant
    Filed: December 18, 2002
    Date of Patent: July 31, 2007
    Assignee: Nortel Networks Limited
    Inventors: Christian Dubuc, Daniel Boudreau, William R. Kirkland
  • Publication number: 20050053169
    Abstract: A rotation by a phase offset is applied to symbols to be transmitted by one antenna relative to symbols to be transmitted from another antenna in a wireless communication system employing multi-element antennas at the transmitter. Such a phase offset allows the functionality of a MIMO system to be maintained when a MIMO channel degenerates. Advantageously, a MIMO system using the new signal design may provide a level of performance in a rich-scattering environment that is equivalent to a MIMO system using a known signal design. Furthermore, a MIMO system employing embodiments of the present invention may show significantly improvements in robustness over conventional MIMO systems.
    Type: Application
    Filed: September 5, 2003
    Publication date: March 10, 2005
    Inventors: Ming Jia, Peiying Zhu, Wen Tong, Christian Dubuc
  • Publication number: 20050041622
    Abstract: The present invention provides an improved channel quality indicator indicia for OFDM communication environments. In addition to taking into consideration carrier-to-interference ratios, the present invention also takes into consideration the degree to which the channel response varies among the sub-carriers throughout the OFDM frequency band. The carrier-to-interference ratio and the degree of channel response variation are directly or indirectly used by a base station to select coding and modulation schemes for transmissions from the base station to the mobile terminal reporting these factors. Further, scheduling of data sent to the mobile terminal and other mobile terminals competing for the same channel resources may also be based in part on the carrier-to-interference ratio and the degree to which the channel response varies.
    Type: Application
    Filed: October 3, 2003
    Publication date: February 24, 2005
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Christian Dubuc, Jason Duggan, Peiying Zhu
  • Patent number: 6812092
    Abstract: A Dynamic Random Access Memory is fabricated in a semiconductor body of a first conductivity type in which there have been formed an array of memory cells which each include a trench capacitor and a vertical Insulated Gate Field Effect Transistor (IGFET). Each IGFET includes first and second output regions of a second opposite conductivity type and a gate which is separated from a surface of the semiconductor body by a gate dielectric layer. A gate electrode connected to the gate is formed using a Damascene process with insulating sidewall spacer regions being formed before the gate electrode is formed. Borderless contacts, which are self aligned, are made to the first output regions of each transistor using a Damascene process.
    Type: Grant
    Filed: December 19, 2000
    Date of Patent: November 2, 2004
    Assignee: Infineon Technologies
    Inventors: Mihel Seitz, Michael Wise, Christian Dubuc
  • Publication number: 20040190640
    Abstract: The present invention divides the available sub-carriers in an OFDM symbol window into N groups of sub-carriers wherein each group will be associated with sub-bands. In one embodiment, the sub-carriers in a group are spread throughout the range of sub-carriers to improve frequency diversity, and the sub-carriers assigned to any one group are separated by a constant offset. The sub-carriers in the group may be offset by an integer power of two. Within each group, sub-bands are defined using frequency hopping patterns among sub-carriers in the group from one OFDM symbol window to another. A pseudo-random pattern may be employed for sub-carrier mapping from one OFDM symbol window to the next to effectively distribute the sub-bands across the selected band of sub-carriers for the group.
    Type: Application
    Filed: February 26, 2004
    Publication date: September 30, 2004
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Christian Dubuc, Colin Brown, Daniel Boudreau
  • Publication number: 20040033659
    Abstract: A Dynamic Random Access Memory is fabricated in a semiconductor body of a first conductivity type in which there have been formed an array of memory cells which each include a trench capacitor and a vertical Insulated Gate Field Effect Transistor (IGFET). Each IGFET includes first and second output regions of a second opposite conductivity type and a gate which is separated from a surface of the semiconductor body by a gate dielectric layer. A gate electrode connected to the gate is formed using a Damascene process with insulating sidewall spacer regions being formed before the gate electrode is formed. Borderless contacts, which are self aligned, are made to the first output regions of each transistor using a Damascene process.
    Type: Application
    Filed: December 19, 2000
    Publication date: February 19, 2004
    Inventors: Mihel Seitz, Michael L. Wise, Christian Dubuc
  • Patent number: 4933888
    Abstract: Process for the digitization and linearization of a quasi-sinusoidal periodic characteristic transducer and the corresponding apparatus.The process consist of measuring a variation (.DELTA..phi..sub.x) of a signal (.phi..sub.x) received by the transducer in accordance with the following operations:superimposing on the signal to be measured a first auxiliary periodic signal (.phi..sub.I) of frequency F.sub.I higher than the highest frequency of the range of the signal to be measured and of amplitude substantially equal to .phi..sub.o /2 and a second auxiliary signal constituted by a periodic linear ramp (.phi..sub.R) of a frequency f.sub.R well below F.sub.I and of amplitude .phi..sub.1, the transducer thus receiving a composite signal constituted by the signal to be measured, the first auxiliary signal and the second auxiliary signal;deducing from the signal supplied by the transducer, two periodic signal V.sub.C1 and V.sub.C2, of period .phi..sub.
    Type: Grant
    Filed: April 25, 1988
    Date of Patent: June 12, 1990
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Daniel Bloyet, Christian Dubuc, Denis Duret, Jacques Lepaisant, Didier Robbes, Khalid Benhida