Self-adaptive echo cancellation method based on time-varying parameters

Abstract

The invention discloses a self-adaptive echo cancellation method based on time-varying parameters. The adaptive echo cancellation method comprises the following steps: A, far-end signal sampling; B, echo signal estimation: obtaining an output value y (n) from the filter input vector X (n) through an seld-adaptive filter, namely, an echo estimation value y (n), y (n) = WT (n) X (n); C, echo signalelimination: subtracting the near-end signal d (n) with echo picked up by the near-end microphone from the output value y (n) of the self-adaptive filter, and sending the subtracted near-end signal d(n) and the subtracted output value y (n) back to the far end, the returned signal being a residual signal e (n), and e (n) = d (n)-; y (n); D, updating a tap weight vector of the filter; estimating aresidual signal square sequence Ae (n) in the window according to the current moment n, obtaining a smooth square value of the residual signal, further obtaining an adjusting parameter (n) of a time-varying proportional control factor and a time-varying proportional control factor gk (n), and finally obtaining an adaptive filter tap weight W (n + 1) at the next moment; and E, enabling n to be equal to n + 1, and repeating the steps A, B, C and D until the conversation is finished. The method has the advantages of good elimination effect on acoustic echoes of a communication system, high 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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