Low complexity phone echo self-adaption eliminating method

A low-complexity, echo-cancellation technology, applied in two-way sound reinforcement telephone systems, etc., can solve problems such as numerous parameters, multiple mixing parameters, and complex transmission, achieving fast convergence and small steady-state errors

Inactive Publication Date: 2013-10-23
SOUTHWEST JIAOTONG UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, due to the large number of internal mixing parameters and complex transmission, the algorithm significantly increases the computational complexity, and there are many parameters, which requires high precision for parameter debugging.

Method used

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  • Low complexity phone echo self-adaption eliminating method
  • Low complexity phone echo self-adaption eliminating method
  • Low complexity phone echo self-adaption eliminating method

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Embodiment

[0052] A low-complexity telephone echo adaptive cancellation method, its steps are as follows:

[0053] A. Remote signal filtering

[0054] Sampling the far-end signal from the far-end to obtain the discrete value x(n) of the remote signal at the current moment n, and filtering the discrete value x(n) of the remote signal through a convex combination adaptive echo cancellation filter to obtain large Step filter value y 1 (n),y 1 (n)=w 1 (n) H x(n) and small step filter value y 2 (n),y 2 (n)=w 2 (n) H x(n); where w 1 (n) and w 2 (n) are respectively the tap weight coefficients of the large step size filter and the small step size filter in the convex combination adaptive echo cancellation filter of the current moment n, and its initial value is zero, and the superscript H represents the conjugate transpose;

[0055] B. Convex combination

[0056] Filter the value y with a large step size 1 (n) and small step filter value y 2 (n) Perform convex combination to obtain...

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Abstract

The invention discloses a low complexity phone echo self-adaption eliminating method. The method mainly comprises the steps of: A, far-end signal filtration: obtaining a large-step filtering value y1(n) and a small-step filtering value y2(n); B, convex combination: completing the convex combination of the large-step filtering value y1(n) and the small-step filtering value y2(n) so as to obtain a combined filtering value y(n), wherein y(n)=lambda(n)y1(n)+(1-lambda(n))y2(n); C, echo cancellation: completing the subtraction of a near-end signal d(n) which has echo and is picked by a near-end microphone and the combined filtering value y(n), and then sending the signal back to a far end, wherein a return signal is a total residual signal e(n), and e(n)=d(n)-y(n); D, updating the weight coefficient of filtering device taps; E, updating the weight of the filtering device, i.e. updating a hybrid parameter a(n) through a formula which is simplified by a sign function; F, defining the weight of the filtering device; and G, setting n=n+1, and repeating the steps of A, B, C, D, E and F until the conversation is over. The method has strong identification capability to sparse telephone communication systems, and particularly has quick convergence rate and small steady state error in a transition period; an echo eliminating effect is good; and moreover, the method is low in calculation complexity, low in hardware cost and easy to implement.

Description

technical field [0001] The invention belongs to the technical field of adaptive echo cancellation for telephone communication. Background technique [0002] With the advancement of technology in recent years, communication technology has been developing day by day, and various new communications emerge in an endless stream, but the most important communication method is still voice communication, and users are more and more concerned about the quality of voice communication. Acoustic echo is the most important factor affecting the quality of voice calls. Acoustic echo in the communication process means that the user hears his own voice repeatedly during the communication process, which is divided into direct echo and indirect echo. Direct echo means that the sound from the speaker directly enters the microphone without any reflection. The delay of this echo is the shortest, which is related to the voice energy of the far-end speaker, the distance and angle between the speak...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04M9/08
Inventor 赵海全芦璐
Owner SOUTHWEST JIAOTONG UNIV
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