Large distance microphone array noise cancellation method and noise cancellation system

A microphone array and noise elimination technology, applied in the field of signal processing, can solve the problem of unsatisfactory noise elimination effect and achieve the effect of improving the noise elimination ability

CN101192411AInactive Publication Date: 2008-06-04VIMICRO CORP
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2008-06-04
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a method for eliminating noise of a long-distance microphone array and a noise-eliminating system. In the invention, the signals collected from two microphones are treated with respect to beam forming, and then the intensified target phonetic signals and the weakened target phonetic signals are obtained; whether target phonetic signals exist in the signals collected from the two microphones is further tested; the update of the adaptive filter coefficient is controlled based on the test result; and lastly, based on a controlled adaptive filter coefficient, the obtained intensified target phonetic signals and the weakened target phonetic signals undergo an adaptive filter process. According to the invention, the performance of noise elimination is greatly improved without affecting the quality of the target phonetics even in case that the microphones are not increased in number.
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Description

technical field

[0001] The invention relates to the field of signal processing, in particular to a noise elimination technology. Background technique

[0002] Noise removal methods are mainly divided into single-microphone de-noising methods and multi-microphone (microphone array) de-noising methods.

[0003] The single-microphone denoising method can achieve better results in specific application scenarios. The algorithm generally uses the difference between the target speech and noise components in the time-frequency domain (for example, it is generally believed that the characteristics of the noise signal change relative to the speech signal Slower), for noise cancellation, so it is suitable for eliminating steady-state noise. Compared with the single-microphone denoising method, the multi-microphone algorithm mainly uses the difference in the spatial domain between the target sound source and the noise source (such as the distance and direction of each sound source to t...

Examples

Embodiment Construction

[0069] The first embodiment of the present invention proposes a noise cancellation system whose structure is shown in Figure 2, including five components: a beamforming unit, a speech detection unit, an adaptive filter, a single-channel speech enhancement unit and an automatic gain control unit .

[0070] The functions of each component are as follows:

[0071] 1. Beamforming unit:

[0072] The beamforming unit is used to perform beamforming processing on the signals collected by the two microphones to obtain an enhanced target voice signal and a weakened target voice signal.

[0073] The input of the beamforming unit is the signals X1(k) and X2(k) collected by two microphones. Through the beamforming algorithm, two output signals are generated, one of which enhances the target voice signal, and the other weakens the target voice. signal, which mainly contains noise.

[0074] The beamforming algorithm mainly processes the signals collected by the microphone array, so that t...