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Method and system for low delay echo cancelling

An echo cancellation and echo technology, applied in two-way sound reinforcement telephone systems, transmission systems, wired transmission systems, etc., can solve the problems of adaptive low processing complexity, algorithm delay, slow adaptive and high processing complexity, etc.

Inactive Publication Date: 2008-07-16
CISCO SYST INT R L
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0049] In conclusion, the advantages and disadvantages of the two methods presented are reciprocal
Full-band echo cancellers have the advantage of zero algorithmic delay, but have the disadvantages of slower adaptation and high processing complexity
The subband echo canceller has the advantages of faster adaptation and lower processing complexity, but has the disadvantage of algorithmic delay

Method used

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  • Method and system for low delay echo cancelling
  • Method and system for low delay echo cancelling
  • Method and system for low delay echo cancelling

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Embodiment Construction

[0059] The present invention will be discussed below by describing preferred embodiments and referring to the accompanying drawings. However, although specific embodiments have been described by way of specific examples, those skilled in the art will appreciate that other applications and modifications are within the scope of the invention as defined by the claims.

[0060] The present invention maintains the fast adaptation of the sub-band echo canceller and the zero delay of the full-band echo canceller. It requires little increase in processing power compared to conventional full-band echo cancellers, and is still very close to the low processing power requirements of conventional sub-band echo cancellers, especially when complex and sophisticated adaptive algorithms are involved.

[0061] In order to describe the present invention, the prior art system of FIG. 3 is explained in detail with reference to FIG. 4, which shows the details of the system.

[0062] As shown in FI...

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Abstract

The present invention discloses an audio echo canceller adapted to provide an echo-reduced output signal based on an echo-added microphone signal consisting of a near-end audio signal and a source by adding an inverted echo estimate. The inverted echo estimate is generated by filtering the far-end audio signal using a full-band FIR filter that includes a set of full-band filter taps. , these taps are generated based on the subband filter taps.

Description

technical field [0001] The present invention relates to audio communication systems and methods having improved acoustic properties, and in particular to conferencing systems including improved audio echo cancellation systems. Background technique [0002] In a conventional conferencing system, one or more microphones capture sound waves at a far-end site and convert the sound waves into a first audio signal. The first audio signal is transmitted to the near-end site where the television and amplifiers and speakers reproduce the original sound waves by converting the first audio signal generated at the far-end site into sound waves. The portion of the sound wave generated at the near-end site is captured by an audio capture system at the near-end site, converted into a second audio signal and transmitted back to the system at said far-end site. The problem of capturing sound waves at one site, transmitting them to another site, and then back to the original site is known as...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04M9/08H04B3/23H03H
CPCH04M9/082
Inventor 特吕格弗·弗雷德里克·马尔通
Owner CISCO SYST INT R L