Patent ID: 6501405
Filing Date: 2002-12-31
Classification: H03M

Abstract:
An apparatus for conversion of a stream of digital input samples in a transmit path of an XDSL modem with both the transmit path and a receive path configured to couple to a communication medium, and the apparatus comprising on the transmit path;an interpolator to interpolate the stream of digital input samples and to provide an oversampled output stream therefrom; a delta sigma modulator (&Dgr;&Sgr;M) having a summation element coupled at a first input terminal to an interpolator to receive the oversampled output stream therefrom, a quantizer to quantize summed values formed by the summation element and an injector coupled on a feedback path between the quantizer and a second input terminal of the summation element, and the injector for injecting into the feedback path digital values which correspond with distortions in an analog portion of the transmit path; and a digital-to-analog (DAC) converter with an input coupled to the quantizer of the &Dgr;&Sgr;M and with an output coupled to the analog portion of the transmit path.