ADSL communication system having echo canceller and method for downloading filter coefficient of the echo canceller

Abstract

The present invention provides an asymmetric communication system having an echo canceller and a method for downloading a filter coefficient to the echo canceller. The echo canceller is a kind of a finite impulse response (FIR) filter for calculating a correlativity between an echo input signal and an echo output signal to generate a filter coefficient. The echo canceller includes a delay line block for delaying an echo input signal for a predetermined interval to generate a delay signal, a filter coefficient table block for sequentially shifting filter coefficients which are sequentially stored in a shift register, and a multiplication and accumulation block for multiplying and adding the delay signal of the delay line block by a filter coefficient that is an output of the filter coefficient table block to generate an echo-cancelled echo output signal. The filter coefficient has the shift rate ratio between the RT mode to the CO mode of the asymmetric communication system.

Dependencies are inferred from the claim text.