The role of a double talk detector (DTD) in acoustic echo cancelation (AEC) system is to detect the presence of near-end speech signal with the microphone signal and freeze the filter adaptation to avoid the adaptive ...
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ISBN:
(纸本)9781538676417
The role of a double talk detector (DTD) in acoustic echo cancelation (AEC) system is to detect the presence of near-end speech signal with the microphone signal and freeze the filter adaptation to avoid the adaptive algorithm divergence. This paper presents a DTD based on an enhanced geigel algorithm where a modified form of decision variable is proposed. The aim is to improve the behavior of geigel algorithm, evaluate performances of the proposed method, and compare it to conventional geigel algorithm. Recursive Least Squares (RLS) algorithm is used in this case as an adaptive filter which it requires a good DTD due to its fast convergence and its sensitivity to double talk situations.
Acoustic Echo Cancellation (AEC) is a topic that has received a great interest in recent years. However, a significant challenge remains with the problem of double-talk especially when the adaptive filter has a fast c...
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Acoustic Echo Cancellation (AEC) is a topic that has received a great interest in recent years. However, a significant challenge remains with the problem of double-talk especially when the adaptive filter has a fast convergence rate. In this case, the double-talk detector (DTD) must reply in early stage and halt updating of the adaptive filter in order to avoid filter coefficients divergence. Indeed, a complex and inappropriate DTD can seriously affect the convergence rate of the adaptive filter and global performances of the AEC system. In this paper, an implementation of a simple and efficient DTD based on a recursive estimation of the decision variable which is resulting from the level comparison between far-end and microphone signals is proposed. The presented algorithm is then compared with the normalized cross-correlation (NCC) method which is taken as a reference in this work. In the simulation tests, the recursive least squares (RLS) algorithm is used to update the adaptive filter coefficients. The speech signals used in the tests are taken from the TIMIT database.
One of the major problems in voiced communication systems is the presence of acoustic echoes generated from the coupling between the loudspeaker and the microphone. In this paper, a new method of Double-Talk Detection...
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ISBN:
(纸本)9781467331227
One of the major problems in voiced communication systems is the presence of acoustic echoes generated from the coupling between the loudspeaker and the microphone. In this paper, a new method of Double-Talk Detection (DTD) for Acoustic Echo Cancellation (AEC), based on the Singular Value Decomposition (SVD), is proposed. Usually, the performances of the AEC, which is based on adaptive filtering, degrade seriously in the presence of speech issued from the near-end speaker (double-talk). Then, Double Talk Detection system must be added to AEC, for controlling the adaptation of the adaptive filter coefficients. For this purpose, we introduce the SVD of the far-end signal for detecting the double-talk periods. The obtained results, using TIMIT database, show that the proposed method outperforms the classical geigel algorithm and Normalized Cross-Correlation (NCC) algorithm.
This paper presents a robust normalized least mean square (NLMS) adaptive scheme for echo cancellation. The scheme combines the advantages of the conventional geigel double talk detector (DTD) with some initiative ide...
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ISBN:
(纸本)9781665403085
This paper presents a robust normalized least mean square (NLMS) adaptive scheme for echo cancellation. The scheme combines the advantages of the conventional geigel double talk detector (DTD) with some initiative ideas. The classical NLMS algorithm is used until the convergence is reached. After that, the controlled NLMS algorithm is used. The Network Echo Canceller (NEC) is implemented in conformity with ITU-T G.168 recommendation. Experiments show that stable performance is ensured during abrupt changes.
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