Patents by Inventor I Zakir Ahmed

I Zakir Ahmed 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: 20110182387
    Abstract: A mechanism for jointly correcting carrier phase and carrier frequency errors in a demodulated signal. A computer system may receive samples of a baseband input signal (resulting from QAM demodulation). The computer system may compute values of a cost function J over a grid in a 2D angle-frequency space. A cost function value J(?,?) is computed for each point (?,?) in the grid by (a) applying a phase adjustment of angle ? and a frequency adjustment of frequency ? to the input signal; (b) performing one or more iterations of the K-means algorithm on the samples of the adjusted signal; (c) generated a sum on each K-means cluster; and (d) adding the sums. The point (?e,?e) in the 2D angle-frequency space that minimizes the cost function J serves an estimate for the carrier phase error and carrier frequency error. The estimated errors may be used to correct the input signal.
    Type: Application
    Filed: January 27, 2010
    Publication date: July 28, 2011
    Inventors: I Zakir Ahmed, Krishna Bharadwaj, Vijaya Yajnanarayana