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. 28, 1997
Filed:
Mar. 02, 1994
Richard W Citta, Oak Park, IL (US);
Gary J Sgrignoli, Mt. Prospect, IL (US);
Rudolf Turner, Hawthorn Woods, IL (US);
Zenith Electronics Corporation, Glenview, IL (US);
Abstract
A digital video field identification system includes video signals formatted in blocks of video symbols in repetitive data segments with each data segment including a synchronizing signal character. One data segment includes a field timing signal. A reference data segment which includes a reference field timing signal is developed at the receiver. A portion of each data segment is compared with the reference field timing signal and the number of symbol errors is accumulated for each data segment. The data segment exhibiting the least number of symbol errors is identified as the one having the field timing signal. A confidence counter stabilizes the identification of the one data segment. For terrestrial transmission, the video signals are precoded in modulo N form to enable NTSC co-channel interference rejection in the receiver by a linear filter. The linear filter undesirably reduces the S/N ratio by 3 dB and a selection circuit is included for bypassing the linear filter (for the video data) based upon the errors developed in the signal paths with and without the linear filter. For cable transmissions no linear filter is included.