Research And Implementation Of Microphone Array Beamforming Algorithm

With the rapid development of voice technology,more and more users intend to obtain a clearer voice system.In some applications such as video,teleconferencing systems,and large conference rooms,it is necessary to implement localization and voice enhancement for sound sources of interest.The traditional single microphone performs enhanced algorithm processing on the collected voice,which easily enters new music noise and causes signal distortion,cannot meet people's requirements for sound quality.The microphone array can automatically detect,locate the sound source,and spatially filter the noise signal to obtain a more obvious effect of enhancing speech by inhibiting noise.This thesis mainly studies the sound source localization algorithm,speech enhancement algorithm and echo and reverberation cancellation algorithm based on microphone array beamforming.The paper studies several typical sound source localization algorithms such as high-resolution spectral estimation of sound source localization technology,controllable waveform formation localization technology based on the maximum output power,and proposes an improved localization technology based on the time of arrival(TDOA).The improved sound source localization algorithm can more accurately identify the position of the sound source and improve the accuracy of the delay estimation.The Convention Beamforming algorithms,the Adaptive Beamforming algorithms and the post-filter beamforming algorithm are studied,and a post-filter beamforming algorithm based on ASNR and MSS is designed.The paper compares and analyzes the performance of several algorithms.Among them,the Convention Beamforming method can achieve speech enhancement to a certain extend.It has a limited effect of removing noise and can only remove coherent noise.In the process of the GSC algorithm,the ability to filter out the noise component of the expected signal is not very good,affecting the overall algorithm.Post-filter beamforming algorithm based on adaptive spectral noise reduction(ASNR)and multi-source selection(MSS)proposed in this paper can reduce noise from mid-band and higher bands,and can also use adaptive ASNR filtering to reduce the influence of low-frequency noise,improve the performance of noise cancellation and the quality of the output audio signal.The paper studies the microphone array reverberation cancellation algorithm and adaptive echo cancellation algorithm.The adaptive echo cancellation algorithm simulates an approximate echo path that infinitely approximates the true echo path by adjusting the weight of the adaptive filter to obtain an estimated echo signal.The algorithm is verified and the results show that the adaptive echo cancellation algorithm can eliminate the echo component in the speech signal,and the processing effect is good.