Near-end crosstalk noise minimization and power reduction for digital subscriber loops

Apparatus for optimizing digital subscriber line (DSL) communications performance over a cable bundle having a plurality of loops and including at least one active DSL loop, comprising:

• means for determining, for a new DSL loop communication, a required bit rate of that new DSL loop communication, the determined required bit rate corresponding to a required band of plural adjacent subcarriers numbering less than a total available band of subcarriers on one of the plurality of loops;
• means for calculating, for a plurality of subcarrier location positions of the required band of plural adjacent subcarriers for the new DSL loop communication within the total available band of subcarriers, a crosstalk noise effect of the new DSL loop communication with respect to the at least one active DSL loop;
• means for choosing a location position for the required band of plural adjacent subcarriers to carry the new DSL loop communication within the total available band of subcarriers where the calculated crosstalk noise effect with respect to the at least one active DSL loop is minimized;
• and
• means for generating a multi-subcarrier DSL signal for the new DSL loop communication having the required band of plural adjacent subcarriers and positioned at the chosen location.

A digital subscriber line (DSL) transmitter connected to a certain loop in a cable bundle having a plurality of other loops and including active DSL loop communications on the other loops, comprising:

• an ATM idle cell removal machine that is operable to determine for a new DSL loop communication on the certain loop a required bit rate that corresponds to a required band of adjacent DMT subcarriers less than a total available number of DMT subcarriers on that certain loop;
• a noise estimation algorithm that is operable to calculate, at each one of a plurality of possible subcarrier positions of the band of adjacent DMT subcarriers within the total available number of DMT subcarriers, a crosstalk noise effect of the new DSL loop communication with respect to the active DSL loop communications on the other loops;
• and
• a noise minimization algorithm that is operable to choose one of the possible subcarrier positions as a location of the required band of adjacent DMT subcarriers within the total available number of DMT subcarriers, wherein the calculated crosstalk noise effect with respect to the active DSL loop communications on the other loops at the chosen one of the possible positions is minimized;
• and
• a DSL signal generator for generating an active DSL loop communication for that new DSL loop communication having the required band of adjacent DMT subcarriers and positioned at the chosen location.