Patent ID: 7564964
Filing Date: 2009-07-21
Classification: H04B

Abstract:
1. An echo canceller for removing an echo component by using an adoptive algorithm, the echo canceller comprising: a pseudo-echo forming means including a pseudo-echo generation section for generating a pseudo-echo signal in accordance with a tap coefficient and a far-end input signal, and a coefficient update section for updating the tap coefficient; a sending filter means for removing a low-frequency component included in a near-end input signal component; a pseudo-echo filter means for removing a low-frequency component included in the pseudo-echo signal from the pseudo-echo forming means; and an echo cancellation means for removing an echo component included in the near-end input signal component passing through the sending filter means, and an echo component in accordance with a pseudo-echo signal passing the pseudo-echo filter means; and a receiving filter means for removing a low-frequency component from the far-end input signal component, the receiving filter means being disposed between a far-end input terminal and the pseudo-echo forming means; wherein the sending filter means, the pseudo-echo filter means, and the receiving filter means are variable filters; the echo canceller further comprising a switch control means which detects presence or absence of a second band component on a sending path and a receiving path, the second band component being different from a first band component that is a conventional telephone band, the echo canceller controlling the removal frequency band of the sending filter means, the pseudo-echo filter means, and the receiving filter means in accordance with a result obtained by the detecting of the second band component.