An Adaptive Echo Cancellation Method Based on Time-varying Parameters

Abstract

The invention discloses an adaptive echo cancellation method based on time-varying parameters. The steps are as follows: A. Remote signal sampling; B. Echo signal estimation, and the filter input vector X(n) is output through an adaptive filter The value y(n), that is, the estimated value of the echo y(n), y(n)=W T (n)X(n); C, echo signal elimination, the near-end signal d(n) with echo picked up by the near-end microphone and the output value y(n) of the adaptive filter are subtracted and then sent back to the far end, the loopback signal is the residual signal e(n), e(n)=d(n)-y(n); D, the filter tap weight vector is updated, and the square of the residual signal in the window is estimated by the current moment n Sequence A e (n), get the smooth square value of the residual signal and then get the adjustment parameter α(n) of the time-varying proportional control factor and the time-varying proportional control factor g k (n), finally obtain the adaptive filter tap weight W(n+1) at the next moment; E, make n=n+1, repeat the steps of A, B, C, and D until the end of the call. The method has a good effect of eliminating the acoustic echo of the communication system, has fast convergence speed and small steady-state error.

Description

technical field [0001] The invention relates to an adaptive echo cancellation method. Background technique [0002] In a voice-based communication system (such as a hands-free phone, a video conference system), the voice quality is usually affected by the echo, mainly the acoustic echo, which seriously affects the call quality. Echo is a phenomenon in which sound or signal is reflected back to the signal source after delay or deformation. In communication systems such as voice communication, data communication, satellite communication, hands-free phone, and teleconferencing system, echo phenomenon exists to varying degrees. . 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 will be received by the local near-end microphone and sent back to the far-end, causing the far-end speaker to hear his own voice. Therefore, effective measures must be taken to eliminate the echo signal, r...

AI Technical Summary

Problems solved by technology

However, the convergence speed of this method in echo cancellation is still not ideal

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