Near-end crosstalk modelling in the digital subscriber loop

Abstract

The importance of near-end crosstalk in digital subscriber loops is reviewed. Three statistical models are examined for predicting the mean and standard deviation of the NEXT interference power from n disturbers. The Bradley model is selected as most accurate with moderate computational complexity. A set of measurements on multipair cable to obtain model parameters is described. Crosstalk coupling on 26 gauge cable is found to vary with f/sup 1.4/, have a mean at 80 kHz equal to -93.7 dB and standard deviation of 11.5 dB. The distribution of the loss in dB across pairs of disturbers is Gaussian. The model is applicable when line codes are compared for the digital subscriber loop.<>