Method for determining equalizer coefficients

A method for determining equalizer coefficients, executed by a test system, the method for determining the equalizer coefficients comprising the following operations:

• (a) setting a plurality of low-frequency equalizer coefficients of a low-frequency equalizer circuit;
• (b) establishing a network connection via the low-frequency equalizer circuit and a decision feedback equalizer circuit, wherein the decision feedback equalizer circuit operates according to an output of the low-frequency equalizer circuit;
• (c) recording a sum of absolute values of a plurality of decision feedback equalizer coefficients of the decision feedback equalizer circuit and a signal-to-noise ratio;
• (d) repeatedly performing the operations (a) to (c) to obtain a plurality of sums of absolute values and a plurality of signal-to-noise ratios;
• (e) selecting a first sum of absolute values from the plurality of sums of absolute values according to a predetermined threshold value and the plurality of signal-to-noise ratios;
• and
• (f) setting the plurality of low-frequency equalizer coefficients as a value combination corresponding to the first sum of absolute values.