Method for fine gains adjustment in an ADSL communications system

In a communications system for transmitting over a plurality of bins, a bin of the plurality of bins for transmitting a predetermined number of bits, a method for fine gain adjustment, the method comprising the steps of:

• selecting a bin of the plurality of bins for gain adjustment by determining that the fine gain adjustment does not exceed a predetermined threshold;
• determining a plurality of margins, a margin of the plurality of margins corresponding to a bin of the plurality of bins;
• iteratively equalizing the plurality of margins by;
• determining an adjustment value;
• applying the adjustment value, to at least one margin of the plurality of margins;
• and
• applying the adjustment value to an adjusted gain corresponding to the at least one margin.

In an asymmetrical digital subscriber line communications system for transmitting a plurality of bins of data, a method for performing a fine gains adjustment, the method comprising the steps of:

• selecting a bin of the plurality of bins for gain adjustment by determining that a gain adjustment does not exceed a predetermined threshold;
• determining a signal-to-noise ratio for each bin of the plurality of bins;
• subtracting a reference signal-to-noise margin from the signal-to-noise ratio for each bin of the plurality of bins, resulting in a plurality of margins, each margin of the plurality of margins corresponding to a bin of the plurality of bins;
• determining a maximum margin and a minimum margin from the plurality of margins;
• adding the maximum margin to the minimum margin resulting in a first sum;
• dividing the first sum by two;
• subtracting the minimum margin from the first sum resulting in an intermediate adjustment value;
• subtracting an adjusted gain corresponding to the minimum margin from the maximum gain, resulting in a minimum tweak value;
• adding an adjusted gain corresponding to the maximum margin to the maximum gain, resulting in a maximum tweak value;
• selecting the smaller of the intermediate adjustment value, the minimum tweak value, or the maximum tweak value to become an adjustment value;
• defining a threshold value;
• determining if the adjustment value is less than the threshold value;
• if the adjustment value is less than the threshold value, the method for performing the fine gain adjustment is complete;
• and
• if the adjustment value is not less than the threshold value, decrease the adjusted gain corresponding to the maximum margin by the adjustment value, increase the adjusted gain corresponding to the minimum margin by the adjustment value, decrease the maximum margin by the adjustment value, and increase the minimum margin by the adjustment value.