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 compatiblemanner for forming enhanced modes for better reception of ATSC DTV signals.This isachieved by an enhanced coding block provided at the input of a conventionalATSC trellisencoder unit. The enhanced coding block comprising a trellis encoder encodesonly therobust stream while passing the normal standard stream unaltered.Fig. 3