Apparatus for, and method of, reducing power dissipation in a communications system

A method for reducing power dissipation within a communications system having at least one adaptive filter with a plurality of taps, each tap switchable between an active and an inactive state, each tap having a coefficient, said method comprising the steps of:

• a) specifying an acceptable level of error for the filter;
• b) for each active tap, setting a tap threshold;
• c) for each active tap, deactivating those taps having a coefficient with an absolute value less than the tap threshold set for the active tap;
• d) computing a filter error;
• e) comparing the computed filter error to the acceptable filter error;
• f) if the computed filter error is less than the acceptable filter error, increasing, the tap threshold for each active tap;
• and
• g) repeating steps c) through f) until the computed filter error approaches the acceptable filter error without exceeding the acceptable filter error.

A method for reducing power dissipation within a communications system having a plurality of adaptive filters with a plurality of taps, each tap switchable between an active and an inactive state, each having a coefficient, said method comprising the steps of:

• a) specifying an acceptable error for the system;
• b) for each active tap, setting a tap threshold;
• c) for each active tap, deactivating those taps having a coefficient with an absolute value less than the tap threshold set for the active tap;
• d) computing a system error;
• e) comparing the computed system error to the acceptable system error;
• f) the computed system error is less than the acceptable system error, increasing the tap threshold for each active tap;
• and
• g) repeating steps c) through f) until the computed system error approaches the acceptable system error without exceeding the acceptable system error.

A method for reducing power dissipation within a communications system having at least one adaptive filter with a plurality of taps, each tap switchable between an active and an inactive state, each tap having a coefficient, said method comprising the steps of:

• a) computing an initial system error
• b) for each active tap, setting a tap error threshold;
• c) for each active tap, deactivating those taps having a coefficient with an absolute value less than the tap error threshold set for the active tap;
• d) computing a subsequent system error;
• e) if the difference between the subsequent system error and the initial system error is less than a prespecified value, increasing the tap error threshold for each active tap;
• and
• f) repeating steps c) through e) until the difference between the subsequent system error and the initial system error exceeds the prespecified value.

A method for reducing power dissipation within a communications system having at least one adaptive filter with a plurality of taps, each tap switchable between an active and an inactive state, each tap having a coefficient, said method comprising the steps of:

• specifying an acceptable error for each tap;
• selectively deactivating those taps which, if deactivated, would produce an error less than the specified acceptable error;
• specifying an acceptable error for the system;
• calculating a system error;
• selectively deactivating those taps which, if deactivated, would result in the calculated system error being less than the acceptable system error.

A communications system comprising:

• a communications line;
• a plurality of adaptive filters responsive to signals carried by the communications line, each adaptive filter having a plurality of taps each having a coefficient, each tap switchable between an active and an inactive state;
• means for specifying a threshold error for the system;
• means for setting the state of each tap;
• means for calculating a present error for the system;
• and
• means for comparing the present error to the threshold error.

A power dissipation reduction system for use in a communication system having at least one adaptive filter having a plurality of taps each having a coefficient, each tap switchable between an active and an inactive state, said power dissipation reduction system comprising:

• means for specifying a threshold error for the system;
• means for setting the state of each tap;
• means for calculating a present error for the system;
• and
• means for comparing the present error to the threshold error.