| 摘要 |
An echo canceler having an FIR filter for removing an echo from a transmission input signal, the echo resulting from a reflection of a received signal through an echo path, and thereby outputting an output signal with the echo cancelled. The echo canceler includes an impulse response estimating system for estimating the impulse response of the echo path at a time t as a function of the received signal, the echo-cancelled output signal, and an estimated impulse response signal, and thereby outputting the estimated impulse response as the estimated impulse response signal; an echo signal estimating system for generating a predicted signal as a function of the estimated impulse response signal and the received signal, and outputting the predicted signal as an estimated echo signal; and a subtractor for subtracting the estimated echo signal from the transmission signal so as to produce the echo-cancelled output signal. The impulse response estimating system estimates the impulse response of the echo path as a function of the received signal and the echo-cancelled signal at the time t, and the received signal and echo-cancelled signal at a time (t-M), M being a natural number.
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