The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 27, 1987
Filed:
Dec. 24, 1985
Sheau-Bao Ng, Plainsboro, NJ (US);
Henry G Lewis, Jr, Hamilton Square, NJ (US);
RCA Corporation, Princeton, NJ (US);
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. The values produced by this multiplication operation are scaled by an adaptation constant and accumulated to produce the filter coefficients which are used to cancel the ghost signals.