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:
Dec. 10, 1996
Filed:
Jul. 08, 1994
Richard W Citta, Oak Park, IL (US);
David A Willming, Palatine, IL (US);
Zenith Electronics Corporation, Glenview, IL (US);
Abstract
A trellis coded modulation system comprises a source of successive 2-bit data symbols X.sub.1, X.sub.2 arranged in a frame format wherein each frame comprises a plurality of data segments each including a plurality of groups of interleaved data symbols. Each group of interleaved data symbols is separately coded by a precoder and convolution encoder to derive coded output symbols Z.sub.0, Z.sub.1, Z.sub.2, which are mapped to respective 8-level symbols for transmission together with periodically generated frame and segment sync symbols. The received signal may be filtered by a linear filter, e.g. a comb filter, to reduce co-channel interference and each group of filtered symbols is applied to a respective first Viterbi decoder for estimating data bits X.sub.1 X.sub.2. Each first decoder preferably comprises a reduced complexity Viterbi decoder responsive to a partial representation of the state of the linear filter. Each group of received symbols may also be directly applied to a respective second Viterbi decoder for estimating data bits X.sub.1 X.sub.2. Estimated data bits X.sub.1 X.sub.2 from the first or second decoders are selected for further processing.