Echo cancellation apparatus, echo cancellation method and communications apparatus

An echo cancellation apparatus which generates and provides an echo-cancelled signal in which an echo signal is cancelled, the echo signal being (i) generated when an amplified sound of a first speech signal is received and (ii) included in a second speech signal, and the echo-cancelled signal being generated from the second speech signal with the echo signal cancelled, the echo cancellation apparatus comprising:

• a first echo replica generating unit configured to generate a first echo replica by processing the first speech signal through a filter whose characteristic is equalized with an acoustic transfer function, of the amplified sound, found until the amplified sound is received;
• a first echo cancelling unit configured to generate a first echo-cancelled signal by subtracting from the second speech signal the first echo replica generated by the first echo replica generating unit, and provide the first echo-cancelled signal;
• and
• a filter updating unit configured to (i) generate a nonlinear-converted echo-cancelled signal by performing nonlinear conversion on the first echo-cancelled signal generated by the first echo cancelling unit, and (ii) update the filter characteristic thereby equalizing the filter characteristic with the acoustic transfer function, using the nonlinear-converted echo-cancelled signal, the first speech signal, and a Lebesgue space 1 (L-1) norm of the first speech signal,
• wherein the filter updating unit is configured to update the filter characteristic, using a ratio of the first speech signal to the L-1 norm of the first speech signal, and the nonlinear-converted echo-cancelled signal.