Fixed point error analysis of linear multichannel precoding for VDSL

Crosstalk interference is the limiting factor in transmission over copper lines. Crosstalk cancellation techniques show great potential for enabling the next leap in DSL transmission rates. An important issue is the effect of finite world length on performance. In this paper we provide an analysis of the performance of linear zero-forcing precoders, used for crosstalk compensation, in the presence of quantization noise. We quantify analytically the trade off between quantization level and transmission rate degradation. We demonstrate, through simulations on real lines, the accuracy of our estimates. Finally, we show how to use these estimates as a design tool for DSL linear crosstalk precoders.