Echo cancellation method and device based on time delay estimation

Abstract

The invention discloses an echo cancellation method and device based on time delay estimation. The method comprises the steps that microphone signals and reference signals are acquired and preprocessed; frequency-point signals with nonlinear conditions in the preprocessed microphone signals and reference signals in a current scene are determined; according to frequency-point signals without nonlinear conditions in the microphone signals and the reference signals, a current time delay estimation value is obtained through calculation; based on the current time delay estimation value, the reference signals are moved; according to the preprocessed microphone signals and the moved reference signals, a self-adaptive filter is updated, and echo cancellation is achieved. By means of the method anddevice, the accuracy of time delay estimation can be improved, and the echo cancellation effect is improved.

Description

technical field [0001] The invention relates to the field of signal processing, in particular to an echo cancellation method and device based on time delay estimation. Background technique [0002] With the continuous development of information technology, all kinds of distributed intelligent hardware are widely used in various fields. As an indispensable link in the interaction of smart devices, echo cancellation has always been a research hotspot for technicians in related fields. [0003] Echo cancellation is a processing method that prevents the far-end sound from returning by eliminating or removing the far-end audio signal picked up by the local microphone. The existing typical echo cancellation scheme is based on the time delay estimation method, and the calculation reference The linear correlation relationship between the signal and the microphone signal, and the time delay corresponding to the maximum cross-correlation is selected as the device time delay, and the ...

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Problems solved by technology

For example, a distributed intelligent hardware device with only single-ended operation authority cannot achieve synchronous resampling of the reference signal and the microphone signal. For example, in daily households, the TV box is used to control the TV. Since the TV box and the TV are mostly provided by different manufacturers, Assume that as a TV box manufacturer, in the voice control of the TV box, it is necessary to perform echo cancellation on the sound played by the TV, and at this time only has the operation authority of the TV box, that is, it can only obtain the source signal transmitted from the TV box to the TV and the microphone of the TV box Collecting signals, among them, the source signal sent by the TV box to the TV is used as a reference signal, and the signal collected by the microphone of the TV box is used as a microphone signal. It is impossible to re-sample the speaker signal and the microphone signal synchronously. At this time, it is necessary to estimate the reference signal and the microphone signal. The delay of the signal, and then realize the echo cancellation according to the delay

[0004] It can be seen that the accuracy of time delay estimation directly affects the effect of echo cancellation. Due to the complex and changeable environment in actual application scenarios, the existing echo cancellation technology based on time delay estimation has a large error in time delay estimation, and the effect of echo cancellation is relatively large. still needs to be improved

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