聯合聲學迴音消除、噪音降低及頻域適應性演算法之定點式DSP實現

Combined Acoustic Echo Cancellation and Noise Reduction And Fixed-point DSP Implementation of Frequency domain adaptive filter

鄭偉廷(weiting cheng)

指導教授 ： 李仲溪

元智大學/工程學院/電機工程學系/碩士(2002年)

摘要

本論文主要對於免手持通訊系統中的聲學迴音及周遭噪音問題以一個聯合聲學迴音消除及噪音降低的架構處理，並且以定點式數位訊號處理器實現頻域適應性濾波器。
在研究的過程中，我們以頻率域能量正規化的GMDF演算法來消除聲學迴音。在噪音降低部分，比較了數種噪音降低的處理方法，我們決定以噪音頻譜估測的方式來降低噪音。並且以先處理聲學迴音消除再將噪音降低為聯合聲學迴音消除及噪音降低的架構。另外，我們以德州儀器公司的TMS320 C5402 DSP完成了頻域適應性濾波器演算法GMDF於免手持通訊系統的聲學迴音消除架構。

關鍵字

聲學迴音消除 ； 噪音降低 ； 定點式數位訊號處理器 ； 頻域適應性濾波器

並列摘要

The main purpose of this thesis is to combine acoustic echo cancellation and noise reduction to solve acoustic echo and ambient noise problems in hands-free telecommunications. We also used fixed-point digital signal processor to implement the frequency domain adaptive filter algorithm. We employed frequency power normalized generalized multidelay adaptive filter(GMDF) algorithm to cancel acoustic echo. For noise reduction, we compared several noise reduction methods. Among these methods, we adopted the spectrum subtraction to diminish ambient noise. We also used TI TMS320 C5402 DSP to realize GMDF algorithm.

並列關鍵字

acoustic echo cancellation ； noise reduction ； fixed point DSP ； frequency domain adaptive filter ； GMDF

參考文獻

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