Analysis of clipping effect in DMT-based ADSL systems

At present, discrete multi-tone (DMT) transceivers receive much attention for the implementation of asymmetric digital subscriber lines (ADSL). This paper analyzes the effect of clipping a DMT-signal, i.e. limiting the signal´s maximum amplitude. An exact expression is given for the signal-to-noise ratio (SNR) degradation due to clipping alone. By combining this expression with the well-known expression for the quantization noise in the A/D-D/A converters, it is shown how clipping can reduce the number of bits of A/D-D/A converters as well as the dynamical range of the line drivers while keeping the overall SNR the same as without clipping