On the Effect of Estimation and Quantization Errors in Downstream VDSL Systems

We investigate the effect of non idealities in the diagonalizing precoder vectoring technique used for cancellation of the far-end crosstalk in downstream VDSL networks. The contribution of the paper is twofold: on one hand we provide analytical formulas to estimate the average bit rates achievable as a function of both relative and absolute estimation errors, on the other hand we show that, by adopting a smart quantization law, the number of quantization bits required for not exceeding a given transmission rate loss can be smaller than that foreseen by previous analyses.