Duplex Acoustic Echo Cancellation

• Main Authors: T. W. Sang, 桑梓文
• Other Authors: S. F. Hsieh
• Format: Others
• Language: en_US
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/08829762185668012373

碩士 === 國立交通大學 === 電信研究所 === 83 === This thesis focuses on closed-loop analysis of duplex acoustic echo cancellation (DAEC) with applications to teleconference and speaker-phone. Adaptation process and closed-loop ERLE are discussed. The causes and prevention of the closed-loop are also discussed. Several double talk detection methods are introduced and their advantages and drawbacks are discussed. An improved method to distinguish double-talk conditions from room impulse response variation is suggested. In the final part of this thesis, a novel acoustic echo cancellation method using a pair of complementary filters is proposed. In this nonadaptive scheme, training coefficients of filter and double talk detection are no longer needed. Computer simulations are provided under different schemes of DAEC''s.