Patents Examined by John K. Pong
  • Patent number: 4703357
    Abstract: An adaptive television deghosting system operates on modulated video signals including a direct signal component and one or more ghost signal components. The system uses synchronously demodulated in-phase and quadrature-phase baseband video signals as the respective real and imaginary input signals to a complex IIR filter. The filter coefficients are developed adaptively from preset initial values using the signals provided by the filter during a training interval. The training interval includes the interval between the leading edge of the vertical sync pulse and the first serration pulse of each field. The filtered training signals are subtracted from a sync-tip reference value to develop a signal which is proportional to the error in the filter coefficient values. The error signal values corresponding to ghost signals are multiplied by the complex conjugate of the training signal values which represent the analogous sampling points of the direct signal.
    Type: Grant
    Filed: December 24, 1985
    Date of Patent: October 27, 1987
    Assignee: RCA Corporation
    Inventors: Sheau-Bao Ng, Henry G. Lewis, Jr.