Patents by Inventor Haralabos Papadopoulos

Haralabos Papadopoulos 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: 20100111232
    Abstract: The techniques and components described herein may improve the performance for a class of reduced-complexity receiver designs for coded OFDM MIMO systems with bit interleaved coded modulation. The receiver structures described are soft-input soft-output inner/outer decoder receiver structures that include one or more of the following: 1) an inner decoder that includes a linear front-end followed by a limited tree-search based on a soft-output M-algorithm; 2) a conventional near-optimal or optimal decoder for the outer binary code; and 3) iterative decoding (ID), whereby decoding (output) information is passed from one decoder module as input to the other and used to refine and improve the inner/outer decoding module outputs.
    Type: Application
    Filed: September 11, 2009
    Publication date: May 6, 2010
    Inventors: Haralabos Papadopoulos, Ming-Yang Chen, Sean A. Ramprashad
  • Publication number: 20100041407
    Abstract: A method and system is disclosed herein for scheduling in a multi-cell environment.
    Type: Application
    Filed: August 10, 2009
    Publication date: February 18, 2010
    Inventors: Giuseppe Caire, Sean A. Ramprashad, Haralabos Papadopoulos
  • Publication number: 20100040163
    Abstract: A method, apparatus and system are disclosed herein for channel classification and adaptation.
    Type: Application
    Filed: August 10, 2009
    Publication date: February 18, 2010
    Inventors: Giuseppe Caire, Carl-Erik W. Sundberg, Haralabos Papadopoulos, Sean A. Ramprashad
  • Publication number: 20100041408
    Abstract: A method and apparatus is disclosed herein for varying transmit power patterns in a multi-cell wireless transmission environment. In one embodiment, the method comprises varying transmit power coordination patterns for base stations in the wireless communication system to jointly vary base station power over a set of virtual channels over base stations within a cluster and across clusters of base stations; and jointly transmitting by groups of the base stations to one or more user terminals in their respective clusters based on the transmit power coordination patterns.
    Type: Application
    Filed: August 10, 2009
    Publication date: February 18, 2010
    Inventors: Giuseppe Caire, Haralabos Papadopoulos, Sean A. Ramprashad, Christine Pepin
  • Publication number: 20090296842
    Abstract: A method and apparatus is disclosed herein for a modified soft output M-algorithm.
    Type: Application
    Filed: June 1, 2009
    Publication date: December 3, 2009
    Inventors: Haralabos Papadopoulos, Carl-Erik W. Sundberg
  • Publication number: 20090285323
    Abstract: A method and apparatus is disclosed herein for adaptive soft output M-algorithm receiver structures. In one embodiment, a device for use in a wireless communication system includes a transmitter, and comprises of a receiver to receive information-bearing signals from the transmitter wirelessly transmitted using OFDM and bit interleaved coded modulation, where the receiver comprises an inner decoder structure having a soft output M-algorithm (SOMA) based multiple-in multiple-out (MIMO) joint demapper that uses a SOMA-based MIMO detection process to perform joint inner demapping over each subtone.
    Type: Application
    Filed: May 15, 2008
    Publication date: November 19, 2009
    Inventors: Carl-Erik W. Sundberg, Haralabos Papadopoulos
  • Publication number: 20090225878
    Abstract: A method and apparatus is disclosed herein for forward-backward SOMA techniques. In one embodiment, the apparatus is a receiver comprising: an inner decoder structure having a soft output M-algorithm (SOMA) based multiple-in multiple-out (MIMO) joint demapper that uses a SOMA-based MIMO detection process to perform joint inner demapping over each tone, where the SOMA-based MIMO joint demapper is operable to identify a best candidate among a number of candidates by searching a detection tree for each tone using a forward pass through the detection tree, where only a number of best alternatives from every level of the tree are expanded and where soft-output related information is collected and stored, and to perform a second pass, following the forward pass, during which soft-output is computed for each bit; and an outer decoder operable with the SOMA-based inner decoder to perform iterative decoding.
    Type: Application
    Filed: December 15, 2008
    Publication date: September 10, 2009
    Inventors: Haralabos Papadopoulos, Carl-Erik W. Sundberg
  • Publication number: 20090213954
    Abstract: A method and apparatus for tree position adaptive SOMA receiver structures are disclosed herein. In one embodiment, a device for use in a wireless communication system comprises a receiver to receive information-bearing signals from the transmitter wirelessly transmitted using OFDM and bit interleaved coded modulation, where the receiver includes an inner decoder structure having a soft output M-algorithm (SOMA) based multiple-in multiple-out (MIMO) joint demapper that uses a SOMA-based MIMO detection process to perform joint inner demapping over each tone, and wherein the SOMA-based MIMO joint demapper is operable to search a detection tree for each tone using a tree-search symbol order that is adapted for each tone based on channel state information and extrinsic information from the outer decoder, where only a number of best alternatives from every level of the tree are expanded.
    Type: Application
    Filed: December 15, 2008
    Publication date: August 27, 2009
    Inventors: Ozgun Bursalioglu, Haralabos Papadopoulos, Carl-Erik W. Sundberg
  • Publication number: 20090075686
    Abstract: A method, apparatus and system is disclosed herein for wireless transmission based on MU-MIMO and two-way training.
    Type: Application
    Filed: September 11, 2008
    Publication date: March 19, 2009
    Inventors: Krishna S. Gomadam, Haralabos Papadopoulos, Carl-Erik W. Sundberg
  • Publication number: 20080304590
    Abstract: A method and apparatus is disclosed herein for wireless transmission from multiple non-colocated antennas. In one embodiment, a wireless communication system comprises a controller to control a set of antenna elements dispersed over multiple, non-collocated base stations to wirelessly transmit information-bearing signals to one or more receivers using OFDM transmission, wherein control unit includes an antenna selection control operable to select non-collocated antenna elements from the set of antenna elements to send at least one signal to a receiver in the wireless communication system from antenna elements located at different base stations, and further wherein the OFDM transmission uses a circular prefix long enough to accommodate a maximum possible relative delay in reception between arrivals of the transmitted signals.
    Type: Application
    Filed: May 30, 2008
    Publication date: December 11, 2008
    Inventors: Carl-Erik W. Sundberg, Haralabos Papadopoulos
  • Publication number: 20080285671
    Abstract: A method and apparatus is disclosed herein for adaptive MaclogMAP-type receiver structures. In one embodiment, a device comprises a receiver to receive information-bearing signals from the transmitter wirelessly transmitted using OFDM and bit interleaved coded modulation, and the receiver comprises an inner decoder structure having a multiple-in multiple-out (MIMO) joint demapper to perform most likely transmitted symbol estimation using a modified MaxLogMAP process that is operable to adapt a degree of metric correction based on quality of OFDM tones.
    Type: Application
    Filed: May 15, 2008
    Publication date: November 20, 2008
    Inventors: Carl-Erik W. Sundberg, Haralabos Papadopoulos
  • Publication number: 20080225751
    Abstract: A method and apparatus is disclosed herein for information delivery with network coding over time-varying network topologies. In one embodiment, the method comprises decomposing a sequence of topology graphs that model a time-varying network topology into a plurality of virtual graphs, where each virtual graph of the plurality of virtual graphs corresponds to a distinct traffic class, and the virtual topology graph representing a partial topology of a time-varying network.
    Type: Application
    Filed: February 29, 2008
    Publication date: September 18, 2008
    Inventors: Ulas C. Kozat, Christine Pepin, Haralabos Papadopoulos, Sean A. Ramprashad, Carl-Erik W. Sundberg
  • Publication number: 20080130769
    Abstract: A method, apparatus and system are disclosed herein for wireless transmission from multiple non-collocated base stations. In one embodiment, the system comprises one or more terminals; and at least two base stations wirelessly communicating information-bearing signals from a set of antenna elements dispersed over multiple, non-collocated base stations to the one or more terminals using coding systems.
    Type: Application
    Filed: November 13, 2007
    Publication date: June 5, 2008
    Inventors: Haralabos Papadopoulos, Carl-Erik W. Sundberg
  • Publication number: 20080123618
    Abstract: A method and apparatus is disclosed herein for asynchronous space-time coded transmission from multiple stations. In one embodiment, the method comprises one or more terminals and at least two base stations wirelessly communicating information-bearing signals to the one or more terminals using orthogonal space-time block codes. In one embodiment, the proposed codes maintain “orthogonality” at the receiver even in the presence of asynchronous signal reception among signals transmitted from distinct transmit base stations.
    Type: Application
    Filed: December 21, 2006
    Publication date: May 29, 2008
    Inventor: Haralabos Papadopoulos
  • Publication number: 20080089333
    Abstract: A method and apparatus is disclosed herein for delivering information over time-varying networks. In one embodiment, the method comprises, for each of a plurality of time intervals, determining a virtual network topology for use over each time interval; selecting for the time interval based on the virtual network topology, a fixed network code for use during the time interval; and coding information to be transmitted over the time-varying network topology using the fixed network code with necessary virtual buffering at each node.
    Type: Application
    Filed: October 16, 2007
    Publication date: April 17, 2008
    Inventors: Ulas C. Kozat, Haralabos Papadopoulos, Christine Pepin, Sean A. Ramprashad, Carl-Erik W. Sundberg
  • Publication number: 20070281633
    Abstract: A method and apparatus is diclosed herein for performing distributed space-time coding. In one embodiment, the distributed space-time coding is used for downlink communications in wireless radio networks. In one embodiment, the method comprises storing information-bearing sequence at two or more base stations in a group of base stations; and transmitting data coprresponding to the information-bearing sequence from a number of base stations for receipt by a reciever of a user, where the number of base stations is not globally known a priori and indicates a diversity of order, such that the diversity of order M is obtained if a total of M number of antennas spread over multiple base stations transmit the information-bearing sequence, where M is an integer.
    Type: Application
    Filed: May 29, 2007
    Publication date: December 6, 2007
    Inventor: Haralabos Papadopoulos