Patents Examined by Daniel T. Pihulk
  • Patent number: 4903247
    Abstract: A digital echo canceller [1] with a good protection against double-talk comprises a first filter [9] for the echo cancellation proper, a second adaptive filter [11] for making continuously adapted filter coefficients available to the first filter [9] and gate means [15] which will only apply the adapted filter coefficients to the first filter [9] if certain conditions are satisfied. In the echo canceller [1] a specific filter combination is used, in which the first filter [9] is a time-domain programmable filter (TDPF) and the second filter [11] is a frequency-domain block-adaptive (FDAF), and further means [20,20(1)] are provided that are arranged in cascade with the gate means [15] for transforming the frequency-domain filter coefficients [W(p;m)] of the FDAF [11] into time-domain filter coefficients [w(i;m)] for the TDPF [9].
    Type: Grant
    Filed: June 23, 1988
    Date of Patent: February 20, 1990
    Assignee: U.S. Philips Corporation
    Inventors: Petrus J. Van Gerwen, Franciscus A. M. van de Laar, Hendrik J. Kotmans