Patents Represented by Attorney B. R. Lipsitz
  • Patent number: 5519733
    Abstract: A method and apparatus are provided for recovering and tracking the carrier in a QAM communication system, even under heavy interference conditions. A subset of fixed points is defined on an ideal constellation pattern for comparison to the data points in a received signal. The subset includes all of the points intersected by n radii (e.g., the four diagonals) of the constellation pattern. Additional points along the perimeter of the constellation pattern can also be provided in the subset. Data points received via a carrier are correlated with the fixed points of the subset in order to generate an error signal indicative of a phase difference between the fixed points of the subset and the received data points correlated therewith.
    Type: Grant
    Filed: May 5, 1994
    Date of Patent: May 21, 1996
    Assignee: General Instrument Corporation of Delaware
    Inventor: Zheng Huang