Trellis coded modulation system for digital television signal

摘要

A trellis coded modulation system comprises a first coder for convolutionally coding a first input data bit X1 for deriving first and second output bits Z0 and Z1. A second coder precodes a second input data bit X2 for deriving an output bit Z2. The output bits Z0, Z1 and Z2 are mapped into corresponding one-dimensional multi-value symbols, wherein the output bits Z0, Z1 identify respective subsets of the symbols, each of the subsets comprising two equally spaced symbol values, and the output bits Z1, Z2 identify respective pairs of the symbols, each of the pairs comprising two adjacent symbol values.