Patent ID: 7623570

Claim:
A method for calculating a frequency equalization coefficient vector of a frequency equalizer to correct a channel distortion of a received signal by using the frequency equalization coefficient vector, the method comprising the steps of: receiving for each frame a signal outputted from the frequency equalizer; normalizing each of the received signals with a predetermined coordinate value to a reference coordinate value; calculating an average value of N number of the normalized received signals at the N-th frame; calculating a unit error correction vector based on the average value; updating the frequency equalization coefficient vector with the calculated unit error correction vector, wherein each of the received signals is a signal encoded in quadrature amplitude modulation (QAM); wherein the step of normalizing each of the received signals includes the steps of: detecting the sign of a real number and the sign of an imaginary number of the received signal; swapping the real number and the imaginary number for each other when the real number sign is different from the imaginary number sign; rotating the coordinates of the received signal to an axis where the real number equals to the imaginary number; and shifting the rotated coordinate of the received signal to the reference coordinate value.