VDSL system based on DMT line coding method and method for determining cyclic prefix sample length in the same system

Disclosed is a VDSL (very high bit-rate digital subscriber line) system on the DMT line coding method basis and a method for determining a length of cyclic prefix samples using the system. The VDSL system comprises a transmitter data including cyclic prefix samples through a channel; a receiver for receiving the data including the cyclic prefix samples; a controller for controlling the transmitter and the receiver to control an initialization operation including handshake, training, channel analysis, and exchange, and a data transmission operation after the initialization operation; and a cyclic prefix sample length estimator for estimating an optimized length of the cyclic prefix sample on the basis of the correlation between the cyclic prefix sample and other data. According to the present invention, since no complex TEQ configuration required when fixing and using the length of the cyclic prefix sample is used, its configuration becomes simpler, and the optimized length of the cyclic prefix sample can be accurately determined.