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:
Jul. 09, 2002
Filed:
Oct. 21, 1999
Kenneth Brakeley Welles, II, Scotia, NY (US);
John Erik Hershey, Ballston Lake, NY (US);
Mark Lewis Grabb, Burnt Hills, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
The existing ATSC broadcast standard is modified to improve both the speed at which the periodically transmitted training sequence is found after channel selection by a viewer and the speed at which synchronization is achieved to a continuous wideband overlay signal used for equalization of the decoded signal. The modification involves slight amplitude modulation of the pilot signal in a manner synchronized with the transmission of the training sequences. The modulation of the pilot signal is sufficiently small to be ignored by existing ATSC receivers; that is, it is backwards compatible. Properly equipped receivers can detect, more quickly than receivers not so equipped, transmission of the training sequence by decoding this pilot signal modulation, thereby being capable of providing a decoded image to a viewer more quickly after a channel change than a receiver not so equipped. Additionally, the time required to synchronize to a continuous wideband overlay signal which has been provided for equalization is reduced, as by varying the modulation slightly to correspond to the start of a particular phase portion of the periodic sequence such as an m-sequence used for the overlay.