DSL TRANSMISSION SYSTEM HAVING ECHO CANCELLER

PROBLEM TO BE SOLVED: To provide a digital subscriber line transmission system having an echo canceller simple in configuration and high in reliability. SOLUTION: This system has an inverse fast Fourier transformation (IFFT) circuit 14 which receives N digital output values as frequency range coefficients, a fast Fourier transformation(FFT) circuit 18 which receives a time area signal and outputs N digital frequency range coefficients as input values, a line interface 16 which couples the IFFT and FFT circuit with a subscriber line 10, and a circuit which inserts cyclic suffixes(CS) at ends of respective symbols while the symbols are part of the time area signal corresponding to the N output values and includes the echo canceler provided so as to subtract the respective output values mutiplied by respective constant magnifications (k) from the respective input values.