Reducing noise in a communication system

A line balance correction device for correcting longitudinal balance of a copper pair, the device being adapted to be connected in parallel to the copper pair and to a local ground, the device comprising:

• a controller;
• and
• at least one current source for connecting to each wire of the copper pair, each said at least one current source being independently controlled by said controller for providing at least one cancellation signal for reducing at least one of the following:
• common-mode noise;
• and differential signal imbalance.

A line balance correction device for correcting longitudinal balance of a copper pair, the device being adapted to be connected in parallel to the copper pair and to a local ground, the device comprising:

• a controller;
• and
• at least one voltage detector operatively associated with said controller for enabling said controller to compute at least one of the following:
• a line imbalance;
• and common-mode noise versus differential signal imbalance.

A line balance correction device for correcting longitudinal balance of a copper pair, the device being adapted to be connected in parallel to the copper pair and to a local ground, the device comprising:

• a controller;
• at least one voltage detector operatively associated with said controller and operative to enable said controller to compute at least one of the following:
• a line imbalance;
• and common-mode noise versus differential signal imbalance;
• a band-pass filter operatively associated with said at least one voltage detector, the band-pass filter being programmable throughout a frequency band of an xDSL transmission and operative to output band-limit signals to said at least one voltage detector;
• at least one variable resistor for connecting to each wire of the copper pair, wherein the resistance of each said at least one variable resistor is independently controlled by said controller for matching, at least up to an acceptable resistance difference level, resistance of signals carried over a corresponding wire of the copper pair to the local ground;
• at least one current source for connecting to each wire of the copper pair, each said at least one current source being independently controlled by said controller for providing at least one cancellation signal for reducing at least one of the following:
• common-mode noise;
• and differential signal imbalance;
• and
• a power supply operative to supply electric power to active components of the device.

A method for correcting longitudinal balance of a copper pair, the method comprising:

• computing at least one of the following:
• common-mode noise on the copper pair;
• and differential signal imbalance on the copper pair;
• and
• providing at least one cancellation signal for respectively reducing at least one of the following:
• said common-mode noise;
• and said differential signal imbalance.

A method for correcting longitudinal balance of a copper pair, the method comprising:

• detecting, for each wire of said copper pair, at least one of the following:
• a RMS voltage;
• and a peak voltage;
• and
• using at least one of said RMS voltage and said peak voltage to compute at least one of the following:
• a line imbalance;
• and common-mode noise versus differential signal imbalance.