Method for determining coefficients of an equalizer and apparatus for determining the same

A method for setting coefficients of a time domain equalizer in a communication system for transmitting a signal through a communication channel having an upstream area and a downstream area so that an error between an output of the time domain equalizer and an output of a channel target circuit becomes zero, the method comprising:

• estimating a frequency response of the upstream area in the communication channel;
• estimating an output of the time domain equalizer from an estimated frequency response of the upstream area and a frequency response of the downstream area;
• determining a cost function J from an estimated output of the time domain equalizer and the output of the channel target circuit,
• wherein the cost function J is given by the following equation:
• J=E{e2}+λ|a|2
• where E is an error function, e is an error between an output of the time domain equalizer and the output of the channel target circuit, λ is an integer except 1, and a is coefficients of the time domain equalizer;
• and
• determining coefficients where the cost function J has a minimum value.