Patents by Inventor Louis Roberts Litwin

Louis Roberts Litwin 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).

  • Publication number: 20090036113
    Abstract: A method and apparatus for controlling a primary cell search operation including generating a profile of correlation peaks, determining if magnitudes of the correlation peaks vary, synchronizing a signal acquisition process to one of the identified correlation peak having a greatest magnitude if the magnitudes of the correlation peaks remain relatively constant and synchronizing the signal acquisition process to a peak whose magnitude is increasing if the magnitudes of the correlation peaks are changing, is described. The method and apparatus further includes identifying an index and a magnitude of a largest correlation peak of the correlation peaks, determining if other correlation peaks exist in the profile, synchronizing the signal acquisition process to the largest correlation peak originally identified if other correlation peaks do not exist, storing indices and magnitudes for all other correlation peaks located and comparing changes in correlation peak magnitudes for all previously identified peaks.
    Type: Application
    Filed: March 28, 2005
    Publication date: February 5, 2009
    Inventors: Louis Robert Litwin, Manoj Viswambharan
  • Patent number: 7468962
    Abstract: The disclosed embodiments relate to a technique for selecting one of several antennas or channels in a receiver based on the quality of the channel response at each of the antennas in a multicarrier system employing convolutional forward error-correction coding. Channel estimates are computed for each subcarrier and monotonic weights are assigned to each subcarrier based on the relative strength of the channel response for that subcarrier. The monotonic weights are mapped to each bit in a symbol for each subcarrier and bits are de-interleaved, if needed. A sliding window evaluation is performed to determine an overall channel quality metric for each channel. The antenna or channel having the highest overall CQM is selected to receive data.
    Type: Grant
    Filed: June 28, 2002
    Date of Patent: December 23, 2008
    Assignee: Thomson Licensing S.A.
    Inventors: Maxim Borisovich Belotserkovsky, Vincent Demoulin, Louis Robert Litwin
  • Patent number: 7463618
    Abstract: A Universal Mobile Telephone System (UMTS) receiver performs slot synchronization using a received primary synchronization channel (PSCH). Subsequent to completion of slot synchronization, the UMTS receiver performs frame synchronization using a received secondary synchronization channel (SSCH) in such a way that the UMTS receiver uses the received primary synchronization channel (PSCH) to detect a change in channel conditions.
    Type: Grant
    Filed: August 4, 2003
    Date of Patent: December 9, 2008
    Assignee: Thomson Licensing
    Inventors: Louis Robert Litwin, Wen Gao
  • Publication number: 20080151839
    Abstract: A Universal Mobile Telephone System (UMTS) receiver performs slot synchronization using a received primary synchronization channel (PSCH) (305). Subsequent to completion of slot synchronization, the UMTS receiver performs frame synchronization using a received secondary synchronization channel (SSCH) (320) in such a way that the UMTS receiver uses the received primary synchronization channel (PSCH) to adjust for the presence of frequency offset (325, 330, 335).
    Type: Application
    Filed: August 4, 2003
    Publication date: June 26, 2008
    Inventors: Louis Robert Litwin, Wen Gao
  • Publication number: 20080144583
    Abstract: A Universal Mobile Telephone System (UMTS) receiver performs slot synchronization using a received primary synchronization channel (PSCH). Subsequent to completion of slot synchronization, the UMTS receiver adaptively controls the duration of processing of the secondary synchronization channel (SSCH) for determining frame synchronization.
    Type: Application
    Filed: August 4, 2003
    Publication date: June 19, 2008
    Inventors: Louis Robert Litwin, Joshua Lawrence Koslov
  • Patent number: 7389463
    Abstract: A method for hierarchically block coding a packet stream includes the steps of appending a packet error correction code to each packet in the packet stream and appending a block error correction code to successive blocks of packets in the packet stream to form a hierarchically error correction coded packet stream. This packet stream is then transmitted through a communications channel. Errors are corrected in each block of packets in response to each block error correction code and errors are corrected in each packet in each block in response to each packet error correction code.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: June 17, 2008
    Assignee: Thomson Licensing
    Inventors: Kumar Ramaswamy, Louis Robert Litwin, Jr.
  • Publication number: 20080137776
    Abstract: A Universal Mobile Telecommunications System (UMTS) receiver comprises an adjustable delay line, a secondary synchronization processor and a controller. The secondary synchronization processor performs frame synchronization on a received wireless signal that is provided via the adjustable delay line. The controller varies the sub-chip timing delays provided by the adjustable delay line until a measure of accuracy of the frame synchronization process exceeds a predetermined threshold, upon which frame synchronization occurs.
    Type: Application
    Filed: January 14, 2005
    Publication date: June 12, 2008
    Inventors: Alton Shelborne Keel, Louis Robert Litwin
  • Publication number: 20080137846
    Abstract: A receiver comprises a memory for storing a scrambling code value and a plurality of fingers, wherein each of the fingers processes a received multipath signal in accordance with at least a portion of the stored scrambling code value for providing symbols associated with a path of the received multipath signal.
    Type: Application
    Filed: January 14, 2005
    Publication date: June 12, 2008
    Inventors: Alton Shelborne Keel, Louis Robert Litwin, Zoran Kostic
  • Publication number: 20080130546
    Abstract: An apparatus comprises a receiver for receiving a multipath signal and a searcher that stores delayed samples of the received multipath signal, wherein the searcher is operative on the delayed samples of the received multipath signal for identifying one or more paths of the received multipath signal.
    Type: Application
    Filed: January 14, 2005
    Publication date: June 5, 2008
    Inventors: Alton Shelborne Keel, Louis Robert Litwin, Zoran Kostic
  • Patent number: 7227835
    Abstract: The disclosed embodiments relate to reducing adjacent channel interference in an OFDM receiver. An error metric is monitored and the carrier frequency of the desired channel is slowly adjusted in response to the error metric. In this manner, the received OFDM signal, including the desired signal corrupted by the adjacent interfering channel, may be shifted until the zero crossings of the adjacent channel line up with the FFT bins. A multi-tap equalizer may then be used to remove the inter-bin interference that results from the frequency offset in the desired channel.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: June 5, 2007
    Assignee: Thomson Licensing
    Inventors: Maxim B. Belotserkovsky, Louis Robert Litwin, Jr.
  • Patent number: 7227886
    Abstract: An apparatus for synchronizing the reception of a spread-spectrum signal includes a synchronization apparatus having a code-matched filter, a running average unit coupled to the filter, a peak detector coupled to the running average unit, and a synchronizer coupled to the peak detector for providing an index of a peak. A corresponding method includes receiving a spread-spectrum signal having a period comprising a plurality of indexable samples, maintaining a mean array comprising a running mean value for each indexable sample over a variable number of periods, detecting a peak value of the array, calculating an average value of the array, computing a peak-to-average ratio in accordance with the detected peak value and the calculated average value, comparing the peak-to-average ratio against a time-varying threshold, and synchronizing the received signal when the peak-to-average ratio exceeds the current value of the threshold.
    Type: Grant
    Filed: July 29, 2002
    Date of Patent: June 5, 2007
    Assignee: Thomson Licensing
    Inventors: Adam Robert Margetts, Louis Robert Litwin, Jr.
  • Patent number: 7162634
    Abstract: A method for creating a secure powerline modem network transmits a private key (y) individually to each of the plurality of powerline modem devices (22) to be secured in a network such that each powerline modem device receives the private key in isolation of the network. Each of the plurality of powerline modem devices store the private key. A public key (X) is computed by a master device (32) in the network to be secured. The public key is transmitted from the master device to the plurality of devices. A shared key (Y) is computed at each of the plurality of powerline devices based on the public key and the private key, and communication within the secured network is performed by employing messages encrypted based on the shared key.
    Type: Grant
    Filed: April 18, 2001
    Date of Patent: January 9, 2007
    Assignee: Thomson Licensing
    Inventors: Louis Robert Litwin, Jr., Kumar Ramaswamy, Michael Anthony Pugel
  • Patent number: 7139966
    Abstract: There is provided a method of diversity error control coding for a system having variable-length packets that carry prioritized data. High priority packets in a data sequence are replicated to form virtual replications. Parity symbols are generated from the data sequence and from the virtual replications, and tag information is generated that indicates a number of the virtual replications used to generate the parity symbols, for subsequent transmission of only the data sequence, the parity symbols, and the tag information to reconstruct the data sequence.
    Type: Grant
    Filed: April 17, 2003
    Date of Patent: November 21, 2006
    Assignee: Thomson Licensing
    Inventors: Louis Robert Litwin, Jr., Kumar Ramaswamy
  • Patent number: 7139554
    Abstract: A system and method for providing a user-selectable status indication to incoming callers is provided, the system including a cellular communications device having a user-selectable status, and a server in signal communication with the cellular communications device for receiving the user-selectable status from the cellular communications device and for updating its logical database; and the corresponding method including the steps of providing a plurality of user-selectable statuses on a cellular communications device, receiving a status selection from a user of the cellular communications device, transmitting the user's status selection to a server, directing an incoming call for the user to the server if the user-selected status is not the Available status, and providing an indication to the incoming caller in accordance with the user's status selection.
    Type: Grant
    Filed: June 24, 2002
    Date of Patent: November 21, 2006
    Assignee: Thomson Licensing
    Inventor: Louis Robert Litwin, Jr.
  • Patent number: 7073083
    Abstract: In a network system having a plurality of devices communicating via a network, a method and system for providing an emergency signal is provided. In one embodiment, a device is malfunctioning if the device continuously transmits data to the network without proper authorization. Another properly functioning device transmits the emergency signal via an auxiliary channel to the malfunctioning device. The auxiliary channel is a separate channel supporting the transmission of the emergency signal. The malfunctioning device receives the emergency signal and disables itself in response to this signal.
    Type: Grant
    Filed: July 18, 2001
    Date of Patent: July 4, 2006
    Assignee: Thomas Licensing
    Inventors: Louis Robert Litwin, Jr., Kumar Ramaswamy
  • Patent number: 7054940
    Abstract: There is provided a method for providing content to network devices in a communication network. A level of congestion of the communication network is determined (305). A cost of service is calculated based on the level of congestion (310). The network devices are informed of the cost of service (315). A first selection is received from a user of a network device specifying a content to be downloaded to the network device during a download process (320). A second selection is received from the user specifying a cost of service threshold for the download process (325). The cost of service is automatically compared to the cost of service threshold (330). The download process is automatically performed, when the cost of service is less than the cost of service threshold (335).
    Type: Grant
    Filed: January 25, 2002
    Date of Patent: May 30, 2006
    Assignee: Thomson Licensing
    Inventor: Louis Robert Litwin
  • Patent number: 7020826
    Abstract: A decoder and decoding method are described, in which a syndrome is calculated from a codeword in a syndrome generator, an error polynomial is generated based upon the syndrome in an error polynomial generator, an error location is determined from the error polynomial in the error location generator, an error magnitude is calculated from the error polynomial in the error magnitude generator and the codeword is corrected by a error corrected codeword generator responsive to location and error magnitude. An intra-decoder block messaging scheme is described in which one or more components generate inactivity messages to signal an ability to process data corresponding to a next codeword. A dual Chien search block implementation is described in which Chien block is used to determine the number of errors corresponding to a specified codeword, separately from error location and magnitude calculations performed by the Chien/Forney block.
    Type: Grant
    Filed: January 23, 2002
    Date of Patent: March 28, 2006
    Assignee: Thomson Licensing
    Inventors: Louis Robert Litwin, Jr., Didier Velez
  • Patent number: 6980651
    Abstract: A method for creating a secure sub-network on a public network that includes a set of devices. The secure sub-network is to include a subset of devices from among the set of devices. An access card is provided having a first private key comprised thereon. The access card is scanned to determine the first private key, by the subset of devices. A master device is determined from among the subset of devices. A second private key is selected and a public key is computed based on the second private key, by the master device. The second private key is only known to the master device. The public key is sent to the set of devices, by the master device. A shared encryption key is computed, and an encryption is requested of any subsequent messages between any of the devices comprising the subset of devices using the shared encryption key.
    Type: Grant
    Filed: June 19, 2001
    Date of Patent: December 27, 2005
    Assignee: Thomson Licensing
    Inventors: Louis Robert Litwin, Jr., Kumar Ramaswamy, Michael Arthur Derrenberger
  • Patent number: 6959055
    Abstract: An apparatus and method for automatic gain control in spread-spectrum communications includes an automatic gain control apparatus for a spread-spectrum receiver, including a received signal strength indicator, an analog amplifier in signal communication with the received signal strength indicator, an analog-to-digital converter in signal communication with the analog amplifier, a digital automatic gain control loop in signal communication with the analog-to-digital converter, and a digital-to-analog converter in signal communication with the digital automatic gain control loop for providing a signal indicative of a digital gain to the analog amplifier; where the corresponding method for automatic gain control in spread-spectrum communications includes receiving an analog signal, measuring the strength of the received analog signal, deriving a first analog gain in correspondence with the measured strength, applying the derived first analog gain to an analog amplifier, deriving a second analog gain from a pilot
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: October 25, 2005
    Assignee: Thomson Licensing
    Inventors: Louis Robert Litwin, Jr., Adam Robert Margetts, Paul Gothard Knutson
  • Patent number: 6944244
    Abstract: A method for initializing an equalizer in an Orthogonal Frequency Division Multiplexing (“OFDM”) receiver includes generating a desired equalizer tap setting based on an adaptive algorithm. An initial setting for the adaptive algorithm corresponds to an approximate inverse of a channel estimate, and the desired tap setting corresponds to an ideal inverse of the channel estimate. In an alternative embodiment, a method includes generating a channel estimate, generating an equalizer tap setting based on a complex conjugate of the estimate and a quantized magnitude squared of the estimate, and repeatedly generating subsequent tap settings until an error falls within limits.
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: September 13, 2005
    Assignee: Thomson Licensing S.A.
    Inventors: Maxim B. Belotserkovsky, Louis Robert Litwin, Jr.