Method for determining system time delay in acoustic echo cancellation and acoustic echo cancellation method

Abstract

The invention relates to a method for determining system time delay in acoustic echo cancellation and an acoustic echo cancellation method employing the method for determining system time delay in acoustic echo cancellation. The method for determining system time delay in acoustic echo cancellation comprises the following steps: overlapping, segmenting and windowing collected original signals and reference signals respectively, and transforming the collected original signals and reference signals respectively into frequency-domain signals through quick Fourier transformation to obtain original frequency-domain signals and reference frequency-domain signals; finding out frequency values corresponding to n peak values with the highest energy in the segmented original frequency-domain signals and reference frequency-domain signals, wherein the frequency values are formant characteristic values; next, sequentially moving the formant frequency sequences of the reference frequency-domain signals forwards by an integral multiple of segmentation time t1, and correspondingly comparing two formant characteristic values respectively, wherein the time delay of forward moving with the most similarities is the system time delay in acoustic echo cancellation. Compared with the prior art, the method can determine dynamic and extra-large system time delay only with a very small amount of calculation, and has a wide application range, a small amount of calculation and a stable effect.

Description

technical field [0001] The invention relates to a method for determining system delay in acoustic echo cancellation and a method for acoustic echo cancellation using the method. Background technique [0002] Acoustic echo refers to the sound collected by the microphone 1' from the sound signal of the speaker 2'. The acoustic echo in voice communication and on-site meetings is harmful and needs to be eliminated by technical means. We will use the Acoustic Echo Canceller (Acoustic Echo Canceller) Abbreviated as AEC. Existing AECs can achieve a good elimination effect under specific systems. However, for some specific devices, the system delay is relatively large, or when the system delay has dynamic changes, many existing AECs will fail. [0003] as attached figure 1 As shown, the working principle of AEC is to use the far-end original signal (Far-end speech) as a reference signal, and use the correlation between the echo signal and the reference signal to separate the near-...

AI Technical Summary

Problems solved by technology

The calculation amount of the LMS method is relatively large, and it cannot adapt to the situation where the system delay is too large, and it is not suitable for the acoustic echo with nonlinear distortion; the method of reading the buffer size to estimate the system delay is too dependent on the system. Real-time operating system, the delay estimation is very inaccurate; the half-duplex echo cancellation method has poor user experience and is only suitable for applications on low-end devices

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