Device and method for echo elimination
A technology of echo cancellation and echo, which is applied in the direction of two-way sound reinforcement telephone system, etc., can solve the problems that the effect of echo cancellation cannot be guaranteed, confusion, etc.
Inactive Publication Date: 2009-10-14
HUAWEI TECH CO LTD
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If the adjustment of the filter coefficients is not stopped in time when the filter coefficients are misadjusted, then the subsequent adjustment of the adaptive filter coefficients may always be in a chaotic state, so the effect of echo cancellation cannot be guaranteed
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[0066] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0067] image 3 The structural block diagram of the specific embodiment one of the echo canceling device provided by the present invention, x (i) in the figure is the signal that produces echo, is called the echo source signal, that is, the signal from the far end received by the near end; g(i) ) is an echo signal; v(i) is a voice signal, that is, the voice signal that the near-end will send to the far-end; d(n) is a voice signal mixed with echo, that is, d(i)=v(i)+g( i), it can be seen that when v(i)=0, d(i)=g(i), such as image 3 As shown, it mainly includes:
[0068] Adaptive filtering module 31: used for saving x(i) when receiving the current segment echo source signal x(i) from the outside, and sending a request coefficient trigger signal to the main filtering module 32, when receiving the main filtering module 32 When outputt...
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The invention discloses an echo canceling device, comprising: an adaptive filtering module, a main filtering module and a first control module. The present invention also discloses an echo cancellation method, which performs self-adaptive adjustment to the currently stored filter coefficient according to the previous echo source signal of the current segment, obtains the adjusted filter coefficient once, and then adjusts the filter coefficient once according to the echo source signal of the current segment The adjusted filter coefficients are subjected to a second adaptive adjustment, and if the adjustment results of the two times satisfy the preset conditions for updating the currently stored filter coefficients, the currently stored filter coefficients are updated with the once adjusted filter coefficients. The present invention ensures the reliability of the saved filter coefficients by further verifying the predetermined conditions for updating the filter coefficients, thereby ensuring the effect of echo cancellation. At the same time, the filter coefficients must meet the predetermined condition for a certain number of times before they can be further stored, which further ensures the accuracy of the stored filter coefficients and the reliability of echo cancellation.
Description
technical field [0001] The invention relates to the field of echo in a voice communication system, in particular to an echo canceling device and method. Background technique [0002] When making a call, especially a long-distance call, we can sometimes hear our own voice after a period of delay from the receiver, which is an echo. Echoes can be uncomfortable, and in severe cases, can even make calls impossible. [0003] Echo is divided into two types according to its generation mechanism: electrical echo and acoustic echo. like figure 1 shown, where R in Indicates the remote input signal, R out Indicates the far-end signal received by the near-end, S in Indicates the near-end input signal, S out Indicates the near-end signal received by the far-end. Taking the far end as an example, the mechanism of electrical echo is as follows: the far end voice signal R in When transmitting in the public switched telephone network (PSTN, Public Switched Telephone Network), it is n...
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IPC IPC(8): H04M9/08
Inventor 欧雄兵靳彤张军曾思南
Owner HUAWEI TECH CO LTD