聲學迴音消除之研究

A Study of Acoustic Echo Cancellation

劉育昇(Yu-sheng Liu)

指導教授 ： 李仲溪 博士

元智大學/工程學院/電機工程學系/碩士(2005年)

摘要

在建構一個舒適的通訊環境系統時，我們所面對的問題包括了有聲學迴音、噪音及雙方談話的干擾。本文中針對聲學迴音、噪音及雙方談話進行研究，利用適應性濾波器以NLMS演算法搭配聯合架構( 聲學迴音消除加上頻率域噪音降低機制 )可使迴音消除機制有不錯的效能，噪音也有抑制的功效。同時在雙方談話的部份我們使用二個相關函數的雙方談話偵測方法也可以有效解決雙方談話問題。
在迴音消除機制中我們也整合了雙邊談話偵測及噪音降低的機制，同時使用在車子、房間、客廳時的聲學迴音路徑來進行實驗，並從模擬結果驗證了我們的分析及呈現出此適當的架構可以提供了一個舒適的通訊系統。

關鍵字

免手持通訊系統 ； 聲學迴音 ； 雙方談話偵測

並列摘要

We may face some problems such as acoustic echo, noise and double-talk of conversation in building up a comfortable communication system environment. In the thesis, we investigate on acoustic echo, noise and double-talk. The acoustic echo cancellation with frequency domain noise reduction will work in canceling the echo and noise. We also use two cross-correlation functions to detect the double-talk situation. We find the method is good by numerous experiment.
We integrate the double-talk detector and noise cancellation in acoustic echo canceller. we use the echo paths of a car, a small room and a living room in experiments. The results verify our analysis and show that the structure we propose is suitable to provide a comfortable communication system.

並列關鍵字

hands-free communication system ； acoustics echo cancellation ； double-talk detector

參考文獻

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