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:
Feb. 15, 1994
Filed:
Feb. 04, 1991
Hugh E White, Pennington, NJ (US);
General Electric Company, Princeton, NJ (US);
Abstract
An NTSC bandwidth-compatible HDTV system employs multiple quadrature amplitude modulation (QAM). A first suppressed QAM carrier is modulated with high priority information including predominantly low frequency information. A second suppressed QAM carrier is modulated with low priority information including predominantly high frequency information. The high priority QAM signal exhibits a larger amplitude and narrower bandwidth than the low priority QAM signal, and is disposed in the lower portion of the multiple QAM frequency spectrum normally occupied by the vestigial sideband of a standard NTSC television signal. The frequency spectrum of the multiple QAM signal exhibits signal attenuation at frequencies associated with high energy information in a standard NTSC signal, e.g., frequencies around the NTSC picture and sound carriers.