在可規劃系統晶片硬體平台實現利用麥克風陣列進行真人語音純化與活動偵測

Abstract

本論文針對室內吵雜環境提出一即時抑制噪音源與真人語音活動偵測系統。並提出一個符合實驗室規模、8通道之即時性麥克風陣列訊號處理實驗平臺，且已實作完成。為了讓系統能適應於噪音源的變化與環境的特徵，論文中設計出一適應性空間濾波器並實做完成，其中適應性空間濾波器的啟動由真人語音活動偵測結果決定。論文中之演算法皆實現於可規劃系統晶片硬體平台上。其中真人語音偵測由Nios微處理器完成，而適應性空間濾波器由自行設計的硬體進行加速並透過Avalon Bus和Nios微處理器進行溝通。由於此適應性空間濾波器的階數為彈性化設計，可以根據不冋的環境狀況做調整，以達到較好的語音純化效果，由實驗證明，此系統能抑制干擾源的影響，有效提高訊號雜訊比。

A real-time speech purification and voice activity detection (VAD) system for noisy indoor environment is proposed in this thesis. The system contains a real-time eight channel microphone array signal processing platform. An adaptive spatial filter is also designed on the platform to provide the system with the ability of environmental characteristic and noise adaptation. All the algorithms are realized on a Nios embedded system-on-programmable-chip (SOPC) platform. The VAD algorithm is executed by the Nios processor and the adaptive filter is accelerated by a self-designed hardware, which is a customized peripheral. The communication between the Nios and processor and the customized peripheral is achieved by the Avalon Bus. Since the order of the spatial filter is flexible, the system can be adjusted for superior speech puirificaiton result. The experimental results verify that the system can suppress the effect of environmental noise and improve the SNR effectively.