TCMs matched to ISI channels: New results for combined symbol-by-symbol equalization and decoding

The design of good TCM schemes matched to ISI channels requires that analytical performance bounds are also available. In this paper, starting from an application of the union-Bhattacharyya bound, upper-bounds for the performance of the theoretically optimum combined symbol-by-symbol (SbS) Abend-Fritchman like equalizer and decoder are presented for the first time in literature. The combined detector acts on the distorted version of the TCM signal received at the output of a channel impaired by (known) ISI and AWGN. On the basis of these bounds a novel simple criterion for the design of TCMs optimally matched to any assigned ISI-corrupted transmission channel is then derived and its application to some actual test-channels is illustrated