Patents by Inventor J. Varaprasad

J. Varaprasad 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: 20090092199
    Abstract: A method and system of estimating frequency offset at a subscriber station is disclosed. One method includes the subscriber station receiving a composite signal, wherein the composite signal includes multi-carrier signals transmitted from a plurality of base stations. The subscriber station selects a first pair of multi-carrier symbols of the composite signal, wherein each multi-carrier symbol of the first pair of multi-carrier symbols includes a pilot sub-carrier having a common sub-carrier index. The subscriber station selects a second pair of multi-carrier symbols of the composite signal, the second pair having different symbol indices than the first pair, but having a same symbol index separation, wherein each of the multi-carrier symbols of the second pair of multi-carrier symbols includes a pilot sub-carrier having a second common sub-carrier index.
    Type: Application
    Filed: November 29, 2007
    Publication date: April 9, 2009
    Inventors: Sriram Mudulodu, Harold Artes, Bertrand Hochwald, Guojie Dong, Robert G. Lorenz, J. Varaprasad
  • Publication number: 20080123544
    Abstract: Methods and systems for estimating Temporal Correlation (TC) of a propagation channel are provided. In an embodiment, a method for estimating the TC of the propagation channel comprises obtaining multiple channel quality reports of the propagation channel and estimating the TC of the propagation channel based on the multiple channel quality reports.
    Type: Application
    Filed: June 22, 2007
    Publication date: May 29, 2008
    Inventors: Djordje Tujkovic, David Garrett, Ying Xia, Erik Lindskog, Brett Schein, J. Varaprasad
  • Publication number: 20070254655
    Abstract: A method and system of training a communication system is disclosed. The method includes a first transceiver transmitting signals through one or more antennas of the first transceiver. A second transceiver selects a subset of a plurality of antennas of the second transceiver, wherein the selected subset provides a largest aggregate received signal power. The second transceiver transmits pilots on a subset of sub-carriers of multi-carrier signals through the selected subset of the plurality of antennas of the second transceiver. The first transceiver receives the pilots, and extracts channel knowledge from the received pilots.
    Type: Application
    Filed: April 26, 2007
    Publication date: November 1, 2007
    Inventors: Djordje Tujkovic, Louay Jalloul, Sam P. Alex, J. Varaprasad