Echo canceller device and echo cancel method

Patent metadata

Field	Value
Publication number	US-10129410-B2
Application number	US-201415510639-A
Country	US
Kind code	B2
Filing date	Dec 15, 2014
Priority date	Dec 15, 2014
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

An echo canceller device includes a band adjuster including a filter for performing band adjustment by applying a gain to a signal in a specific frequency band of an input signal, an adaptive filter for inputting a speech reception signal, updating a filter coefficient, and generating a pseudo echo signal using the updated filter coefficient, a band corrector including a filter for correcting a frequency characteristic of a signal obtained by subtracting the pseudo echo signal from an input signal, to a frequency characteristic of the input signal prior to the band adjustment, and a residual echo suppressor for suppressing an echo component that remains in a signal, by a suppression amount, and the residual echo suppressor sets the suppression amount for a signal in a specific frequency band that has been subjected to the band adjustment.

First claim

The invention claimed is:

1. An echo canceller device to cancel, from an input signal including an echo component of a speech reception signal and a speech transmission signal, the echo component of the speech reception signal, the echo canceller device comprising:
a band adjuster including a filter to perform band adjustment by applying a gain to a signal in a specific frequency band of the input signal;
an adaptive filter to input the speech reception signal, update a filter coefficient, and generate a pseudo echo signal using the updated filter coefficient;
a band corrector including a filter to correct a frequency characteristic of a signal obtained by subtracting the pseudo echo signal generated by the adaptive filter from a signal that has been subjected to the band adjustment performed by the band adjuster, to a frequency characteristic of the input signal prior to the band adjustment performed by the band adjuster, and
a residual echo suppressor to suppress an echo component that remains in a signal of which the frequency characteristic has been corrected by the band corrector, by a suppression amount set based on filter information of the band adjuster, and
wherein the residual echo suppressor sets the suppression amount for a signal in a specific frequency band that has been subjected to the band adjustment performed by the band adjuster in such a manner as to be lower than suppression amounts for signals in other frequency bands.

2. The echo canceller device according to claim 1 , wherein the residual echo suppressor sets a suppression amount of the residual echo component, based on a resonance frequency, a gain, and a Q value in filter information of the band adjuster.

3. The echo canceller device according to claim 1 , wherein the band adjuster and the band corrector set the filters according to a voice band of the speech reception signal.

4. The echo canceller device according to claim 3 , further comprising a signal analyzer to analyze the voice band of the speech reception signal, and to determine whether the voice band of the speech reception signal is a narrow-bandwidth telephone call band, or a high-bandwidth telephone call band.

5. An echo cancel method for cancelling, from an input signal including an echo component of a speech reception signal and a speech transmission signal, the echo component of the speech reception signal, the echo cancel method comprising:
performing band adjustment by applying a gain to a signal in a specific frequency band of the input signal;
inputting the speech reception signal, updating a filter coefficient, and generating a pseudo echo signal using the updated filter coefficient;
correcting a frequency characteristic of a signal obtained by subtracting the pseudo echo signal generated by an adaptive filter from the input signal that has been subjected to the band adjustment, to a frequency characteristic of the input signal prior to implementation of the band adjustment, and
suppressing an echo component that remains in a signal of which the frequency characteristic has been corrected based on band adjustment information of the band adjustment.

Assignees

• Mitsubishi Electric Corp
• Mistubishi Electric Corp

Inventors

• Awano Tomoharu
• Furuta Satoru
• Yamaura Tadashi

Classifications

• H04M1/6083

  by interfacing with the vehicle audio system · CPC title

• H04B3/232

  using phase shift, phase roll or frequency offset correction · CPC title

• H04M9/082 Primary

  using echo cancellers (echo cancellers per se H04B3/23) · CPC title

• H04B3/234

  using double talk detection · CPC title

• H04M9/08

  Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic · CPC title