Author:

Keywords:

adsl, multicarrier modulation, turbo equalization, transceivers, interference, SISTA, Science & Technology, Technology, Engineering, Electrical & Electronic, Engineering, ADSL, INTERFERENCE, 0801 Artificial Intelligence and Image Processing, 0906 Electrical and Electronic Engineering, Networking & Telecommunications, 4006 Communications engineering, 4603 Computer vision and multimedia computation

Abstract:

We study the equalization procedure in discrete multitone (DMT)-based systems, in particular, in DMT-based ADSL systems. Traditionally, equalization is performed in the time domain by means of a channel shortening filter. Shifting the equalization operations to the frequency domain, as is done in per-tone equalization, increases the achieved bitrate by 5-10%. We show that the application of the turbo principle to per-tone equalization can provide significant additional gains. In the proposed receiver structure, referred to as a "turbo-per-tone equalization" structure, equalization and decoding are performed in an iterative fashion. Equalization is done by means of a linear minimum mean squared error (MMSE) equalizer, using a priori information. We give a description of an efficient implementation of such an equalizer in the per-tone structure. Simulations show that we obtain a bitrate increase of 12-16% compared to the original per-tone equalization-based receiver structure.