Performance of module-type Viterbi decoder for digital subscriber loops

Abstract

In this paper, we discuss the performance and computational complexity of module-type Viterbi decoder (MVD) for high-speed digital transmission applications. It is shown that the MVD, which is a combination of module operation and Viterbi decoder at the receiver, has the same performance as a conventional Viterbi decoder (CVD) with extended constellations. We also show by complexity analysis that the MVD in conjunction with the Tomlinson-Harashima (TH) pre-coder at the transmitter reduces the system complexity significantly as compared to the CVD. The performance of the digital subscriber line (xDSL) system employing the MVD is investigated in the presence of near-end crosstalk (NEXT) and impulsive noise.