Frequency Domain Echo Canceller for DMT-Based Systems

This letter addresses echo cancellation for digital subscriber line (DSL) communications with discrete multitone (DMT) modulation. The described adaptive echo canceller operates entirely in the frequency domain. The method allows estimation and subtraction of an echo signal impaired by intercarrier and intersymbol interference present when the impulse response of the echo channel is longer than the cyclic prefix. Implementation aspects for symmetric and asymmetric DMT-based systems are described together with ways to lower the computational complexity. Finally, computer simulation results are presented that validates the proposed method.