Normalization sub-band self-adaptive echo elimination method of biased compensation

A technology of echo cancellation and normalization, which is applied in the direction of two-way sound reinforcement telephone system, telephone communication, electrical components, etc., can solve the problems of large steady-state error, achieve reduced deviation, good echo cancellation effect, and reduce steady-state error Effect

Active Publication Date: 2016-11-30
SOUTHWEST JIAOTONG UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, this method exhibits a large steady-state error when the adaptive filter input signal is noisy

Method used

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  • Normalization sub-band self-adaptive echo elimination method of biased compensation
  • Normalization sub-band self-adaptive echo elimination method of biased compensation
  • Normalization sub-band self-adaptive echo elimination method of biased compensation

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Embodiment

[0033] A specific embodiment of the present invention is a normalized sub-band adaptive echo cancellation method with bias compensation, the steps of which are as follows:

[0034] A. Obtain the subband signal

[0035] Sampling the far-end signal from the far-end to obtain the discrete value x(n) of the far-end signal at the sampling time n, and obtaining the M remote sub-band signals x at the sampling time n by analyzing the filter bank 1 (n),x 2 (n),...x m (n),...x M (n), where m is the subband serial number, x m (n) is the mth remote sub-band signal, M is the number of sub-bands, and its values ​​are 2, 4, 8, 16, 32;

[0036] The near-end signal with echo picked up by the near-end microphone is sampled to obtain the discrete value d(n) of the near-end signal at the sampling time n, and the M near-end band signals d at the sampling time n are obtained by analyzing the filter bank 1 (n),d 2 (n),...d m (n)...,d M (n); where, d m (n) is the mth near-terminal band signa...

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Abstract

The invention provides a normalization sub-band self-adaptive echo elimination method of biased compensation. The method comprises the following steps of: A, obtaining a sub-band signal; B, carrying out self-adaptive filtering, obtaining an mth output value ym(k) at the sampling moment n=kM through a self-adaptive filter from an mth input vector Km(k) of the self-adaptive filter at the sampling moment n=kM, wherein ym(k) is shown in the specification; C, carrying out echo cancelling, subtracting the mth filter output value ym(k) at the sampling moment n=kM from a kth time segment extraction value d<->m(k) of an mth near-end sub-band signal to obtain an mth sub-band residual em(k) at the sampling moment n=kM, wherein em(k)=d<->m(k)-ym(k); D, carrying out filter tap weight vector updating, using a normalization sub-band method of biased compensation to obtain a tap weight vector w(k+1) of the self-adaptive filter at the moment n=(k+1)M, wherein w(k+1) is shown in the specification; and E, for k=k+1, repeating B, C and D steps until the conversation ends. The method has the advantages that the acoustic echo elimination effect of a communication system is good, the convergence speed is high, and the steady-state error is small.

Description

technical field [0001] The invention relates to a normalized sub-band self-adaptive echo cancellation method with bias compensation, and belongs to the technical field of echo cancellation for communication. Background technique [0002] Echo exists in various communication systems, and it is inevitable to have echo problems in the occasions where speakers and microphones are used at the same time, such as hands-free phones, mobile phones, Internet phones, and video conference systems. Take video conference as an example, because the speaker and the microphone are placed in the same space, the far-end voice from the local speaker is received by the local microphone and transmitted back to the far end, causing the far-end speaker to hear his own voice, which is the echo. In communication, the human ear is extremely sensitive to this echo. The echo delayed by 10ms can be captured and perceived by the human ear, and the echo exceeding 32ms will cause great interference to the c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04M9/08
CPCH04M9/082
Inventor 赵海全郑宗生
Owner SOUTHWEST JIAOTONG UNIV
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