Patents Assigned to The United States of America as represented by the Secretary of the National Security Agency
  • Patent number: 7444128
    Abstract: A method of estimating the carrier frequency of a signal is disclosed. The method comprising the steps of initializing a time average vector to zero, selecting a user-selectable time segment to divide a received signal into. A signal is received, and divided into the user-selectable time segments. A spectral peak vector is calculated by performing a spectral estimation process on the user-selectable time segment divided signal. A first correlation vector is calculated on the spectral peak vector, and a second correlation vector is calculated from the spectral peak vector and the first correlation vector. The time average vector is appended with the result from the second correlation vector, and the process repeats for each time segment the received signal was broken into. The carrier is estimated using the most commonly occurring frequency in the time average vector.
    Type: Grant
    Filed: January 19, 2006
    Date of Patent: October 28, 2008
    Assignee: The United States of America as represented by the Secretary of the National Security Agency
    Inventor: Douglas J. Nelson
  • Patent number: 5812609
    Abstract: A communications intercept device that includes an analog-to-digital converter for digitizing an analog wideband input signal, a first memory for storing the digitized wideband signal, a first digital drop receiver in a first tier for selecting signals stored in the first memory, a controller for controlling which signals are selected, a second memory for storing the signals selected by the first digital drop receiver, and a second digital drop receiver in a second tier for selecting signals stored in the second memory under control of the controller.
    Type: Grant
    Filed: July 2, 1996
    Date of Patent: September 22, 1998
    Assignee: The United States of America as represented by the Secretary of the National Security Agency
    Inventor: Charles David McLochlin