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:
Jan. 05, 1993
Filed:
Jul. 31, 1990
James J Gibson, Princeton, NJ (US);
Krishnamurthy Jonnalagadda, Plainsboro, NJ (US);
RCA Licensing Corporation, Princeton, NJ (US);
Abstract
High definition or enhanced television signals include supplementary information which is double-sideband modulated in quadrature with the picture carrier, and passed through an inverse Nyquist filter before being combined with a conventional vestigial sideband modulated main video signal. A receiver which recovers both the main video signal and the supplementary information processes the received video signal through an IF filter having a vestigial sideband frequency response characteristic. Two synchronous detectors recover in-phase and quadrature phase signal components from the filtered television signals, these recovered signals each include quadrature crosstalk distortion components from the other signal. The crosstalk from the supplementary signal into the main signal is canceled by filtering the recovered quadrature signal and adding the result to the recovered in-phase signal. This filtering also equalizes the in-phase signal by converting the quadrature distortion components in the recovered quadrature signal into reenforcing signal components in the in-phase signal. This signal recovery system is advantageously used with a ghost cancellation system.