Abstract: An ADSL modem apparatus that serves as an ATU-R receives a signal in the hyperframe format having FEXT and NEXT parts, when an initialization sequence is started, the signal configured with a known number of symbols. The received signal is sampled by an AFE and stored in a buffer memory of an FFT unit. A processor establishes a symbol synchronization and a hyperframe synchronization, upon receiving an original signal, based on sample data of the original signal, the original signal having REVERB signals during a FEXT period and non-REVERB signals (distinguishable from REVERB signals) during a NEXT period.