An equalization apparatus and method estimate a channel response based on a received signal and a reference signal. Equalization processing estimates intersymbol interference with the received signal based on a channel response estimation results. A decoding error is detected based on the equalization processing to provide an error detection result. A power level threshold for the channel response estimation result is controlled based on the channel response estimation result of the received signal and the error detection result. The number of states for the equalization processing is determined, the number of taps employed in the equalization process is determined, and the number of taps used when the channel response is estimated is determined.