Method and apparatus for estimating/removing echo signal using channel coefficient predicting technique in multi-carrier system

A wireless repeater for removing an echo signal in a multi-carrier system, the wireless repeater comprising:

• an echo channel estimating unit for estimating a current echo channel coefficient of a current train signal section comprising a preamble;
• an echo channel linear prediction coefficient estimator for estimating a current echo channel linear prediction coefficient, which represents a coefficient between the current train signal section and a previous train signal section, using the current echo channel coefficient and a previous echo channel coefficient, which is an echo channel coefficient of the previous train signal section;
• a next echo channel coefficient estimator for estimating a next echo channel coefficient using the current echo channel coefficient, the previous echo channel coefficient, and the current echo channel linear prediction coefficient;
• and
• an echo channel coefficient estimator outside the train signal section, for estimating an echo channel coefficient outside the train signal section using the current echo channel coefficient and the next echo channel coefficient.