ACHIEVABLE INFORMATION RATES ON DIGITAL SUBSCRIBER LOOPS - LIMITING INFORMATION RATES WITH CROSSTALK NOISE

This paper examines the capacity and cutoff rates for channels with linear intersymbol interference, power dependent crosstalk noise, and additive white noise, focusing on high speed digital subscriber line data transmission. The effects of varying the level of additive white noise, crosstalk coupling gain, sampling rate, and input power levels are studied in detail for a set of simulated two-wire local loops. We develop a closed-form expression for the shell constrained Gaussian cutoff rate on the crosstalk limited channel and relate this quantity to the capacity, showing that the relationship between these two rates is the same as on a channel without crosstalk noise. The study also projects achievable rates on a digital subscriber line, inside and outside of a carrier serving area, with a sophisticated, but realizable receiver.