Performance evaluation of a sign-error-based iterative precoder for crosstalk cancelation in DSL systems

In this paper, we present some theoretical performance evaluation of the crosstalk precancelation method presented in the work of Louveaux and van der Venn (2006) for DSL systems. This algorithm uses a limited feedback from the different receivers, returning only the (complex) sign of the error on the detected symbols. It updates the precoder iteratively based on this information and on the knowledge of the transmitted symbols. Very little simulation results had been presented. Here we first propose a slightly modified and simplified version of the algorithm which is significantly less complex. We derive approximate performance expressions for this modified version and compare them to simulation results, showing a very good match. It is then shown how these results can be used to set the different parameters of the method.