Patents by Inventor Scott W. Stewart

Scott W. Stewart 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).

  • Carrier acquisition scheme for QAM and QPSK data
    Patent number: 5042052
    Abstract: The invention involves an apparatus for recovering the carrier signal in OPSK or QAM data. First an energy directed phase detector controls a voltage controlled oscillator so that the output signal has a phase that is within a few degrees of the carrier phase. Following this coarse acquisition, the system clock timing is recovered and established. A decision directed phase detector, using the system clock information, then controls the VCO to adjust the output signal phase to within a very small tolerance of the actual carrier phase.
    Type: Grant
    Filed: February 16, 1990
    Date of Patent: August 20, 1991
    Assignee: Harris Corporation
    Inventors: Richard D. Roberts, James C. Richards, James F. Roesch, Scott W. Stewart, Mark A. Webster