A TRELLIS ENCODER WITH RATE 1/4 AND 1/2 FOR A BACKWARD COMPATIBLE ROBUST ENCODING ATSC DTV TRANSMISSION SYSTEM

摘要

Robust and existing standard bit streams are mixed in a backward compatib le manner for forming enhanced modes for better reception of ATSC DTV signals. This is achieved by an enhanced coding block provided at the input of a conventional ATSC trellis encoder unit. The enhanced coding block comprising a trellis encoder encodes only the robust stream while passing the normal standard stream unaltered. Fig. 3