Coefficient difference based proportional subband convex combination adaptive echo cancellation method

A technology of echo cancellation and convex combination, applied in two-way sound reinforcement telephone system, telephone communication, electrical components, etc., can solve the problems of slow convergence speed, poor steady-state error, and no utilization.

Active Publication Date: 2017-01-11
杭州东南吉通网络有限公司
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Problems solved by technology

However, in the sparse system, the algorithm does not take advantage of the characteristics of the sparse system, that is, the step size of the large step size will become smaller, resulting in slower convergence speed and the smaller step size of the small step size will lead to worsening of the steady-state error

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  • Coefficient difference based proportional subband convex combination adaptive echo cancellation method
  • Coefficient difference based proportional subband convex combination adaptive echo cancellation method
  • Coefficient difference based proportional subband convex combination adaptive echo cancellation method

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Embodiment

[0056] 1, a kind of proportional sub-band convex combination adaptive echo cancellation method based on coefficient difference, its steps are as follows:

[0057] A. Signal segmentation

[0058] The sampled remote signal between the current time n and the time n-L+1 constitutes the input vector U(n) of the current time n, U(n)=[u(n),u(n-1),.. .,u(n-L+1)] T ; L=512 is the number of taps of the filter, and the superscript T represents the transpose operation;

[0059] The input vector U(n) is divided into I remote subband vectors U by analysis filter one i (n), U i (n)=[u i (n), u i (n-1),...,u i (n-L+1)] T ;

[0060] At the same time, the near-end signal d(n) with echo at the current moment n picked up by the near-end microphone is divided into two by the analysis filter into I near-end band signals d i (n);

[0061] Wherein, i is the sequence number of the far terminal band vector or the near terminal band signal, i=1, 2,..., I, and I is the total number of the far t...

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Abstract

The invention discloses a coefficient difference based proportional subband convex combination adaptive echo cancellation method. The method comprises the following steps: A, segmentation of signals, segmenting an input vector U (n) into I far-end subband vectors U (n) by an analysis filter; B, extraction of the signals, carrying out I extraction on the far-end input subband vectors U (n) by an extractor to obtain filtered input subband extraction vectors; C, output of the filter, filtering the filtered input subband extraction vectors U (k) via a convex combination adaptive echo cancellation filter to respectively obtain large-step sub band filtered values y, (k) and small-step subband filtered values y<2>, (k), and carrying out convex combination to obtain combined subband filtered values y (k); D, echo cancellation; E, coefficient difference proportional calculation; F, calculation of the convex combination; G, update of filter tap weight vectors; and H, iteration, supposing k is equal to k plus 1 and repeating the steps A, B, C, D, E, F and G till the end of a call. The method has obvious effect to acoustic echo elimination of a communication system; and meanwhile, relatively fast convergence speed and relatively low steady-state error can be obtained.

Description

technical field [0001] The invention belongs to the technical field of self-adaptive echo cancellation for communication. Background technique [0002] In communication systems, the interference of noise and echo cannot be ignored. Among them, the most important impact on the quality of voice calls is the acoustic echo. Acoustic echo refers to the ability for users to hear their own voice repeatedly during communication. Short echo delays are imperceptible and can be understood as a form of spectral distortion. On the contrary, if the delay exceeds tens of milliseconds, the echo can be detected alone. Since the human ear is extremely sensitive to echoes, research on methods for canceling acoustic echoes is still a hot topic. [0003] In the adaptive echo cancellation method, the widely used methods mainly include the traditional least mean square (LMS) algorithm and the affine projection (APA) algorithm. But in the echo channel, most of them are sparse channels, and the...

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): H04M9/08
CPCH04M9/082
Inventor赵海全刘倩倩
Owner杭州东南吉通网络有限公司