Channel Coding for DTTB System

The DTTB system is aimed at delivering digital video programs reliably over the air to user terminals. This chapter introduces the channel coding for DTTB systems with an emphasis on the basic coding concepts and important conclusions for DTTB system design. Error control methods can be divided into two types. One is with feedback, including automatic repeat request (ARQ), information repeat request (IRQ), and hybrid error correction (HEC). Linear block code based on a well-established theory has very clear mathematical structure and has been widely adopted. Under the same code rate and complexity, convolutional codes in general outperform block codes by fully taking the advantage of correlations among codewords. Parallel code is another combination using short codes to form a long code. The chapter also introduces trellis-coded modulation (TCM) technology by combining coding and modulation, with the signal space partition optimized based on the maximum Euclidean distance criterion.