Ikanos Communications, Inc.

Globespan Virata Corporation

William Edward Keasler, Jr

Laurent Alloin

Arnold Muralt

Laurent Pierrugues

The present invention relates to methods and apparatuses for sensing noise sources in a wireline communications environment such as a customer premises environment in a DSL system. In embodiments, the invention includes an additional sensor that is connected to power mains in a DSL customer premises environment either to characterize, at their source, noises coupling into the DSL lines, and/or to mitigate their impact into the DSL lines. One objective is associated with diagnostics that help to better characterize the noise signals themselves and derive correlation of signals sensed from the power mains and their possible projection onto the DSL line. Another objective makes use of these power line sensor signals to mitigate or to eliminate power line noises that make their way onto the DSL line. Example embodiments further include and exploit signals from additional secondary sensors such as secondary common mode, differential mode and phantom mode sensors.

Method and apparatus for sensing noise signals in a wireline communications environment

The invention is a method and apparatus for a digital DSL line driver that comprise a multi stage delta-sigma modulator with a high current 1-bit digital-to-analog converter (DAC) output stage. By adding the high current drive capability to the 1-bit DAC in a delta-sigma digital-to-analog converter the traditional DSL line driver used in digital subscriber lines applications is made less complex and it saves on the overall power consumption. The invention uses a transistor switch arrangement to save the overall power by alternately switching &ldquo;ON&rdquo; some the transistors while having other transistor turned &ldquo;OFF&rdquo;.

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Tinton Falls, NJ, United States of America

William Edward Keasler, Jr