A traceback device of a trellis decoder including a memory for storing survivor path information as much as a decision depth, a multiplexing unit for decoding the survivor path information received from the memorizing unit, and a traceback unit receiving the survivor path information of lower bits decoded...http://www.google.com/patents/US6031876?utm_source=gb-gplus-sharePatent US6031876 - Trellis decoder for ATSC 8VSB
