Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Robust time delay estimation for speech signals using information theory: A comparison study | Wen and Wan EURASIP Journal on Audio Speech and Music Processing 2011 2011 3 http content 2011 1 3 D EURASIP Journal on Audio Speech and Music Processing a SpringerOpen Journal RESEARCH Open Access Robust time delay estimation for speech signals using information theory A comparison study Fei Wen and Qun Wan Abstract Time delay estimation TDE is a fundamental subsystem for a speaker localization and tracking system. Most of the traditional TDE methods are based on second-order statistics SOS under Gaussian assumption for the source. This article resolves the TDE problem using two information-theoretic measures joint entropy and mutual information MI which can be considered to indirectly include higher order statistics HOS . The TDE solutions using the two measures are presented for both Gaussian and Laplacian models. We show that for stationary signals the two measures are equivalent for TDE. However for non-stationary signals . noisy speech signals maximizing MI gives more consistent estimate than minimizing joint entropy. Moreover an existing idea of using modified MI to embed information about reverberation is generalized to the multiple microphones case. From the experimental results for speech signals this scheme with Gaussian model shows the most robust performance in various noisy and reverberant environments. Introduction Time delay estimation TDE is a basic problem in modern signal processing and it has found extensive applications such as localizing and tracking radiating sources in radar and sonar. Nowadays the same technique is used to localize and track acoustic sources in room environments. For example in automatic camera tracking for video conferencing 1 2 the location of the current speaker is required for the camera to turn toward them in speech enhancement 3 4 using a steerable microphone array the speaker location is required for noise cancellation. TDE for speech signals in adverse acoustic environments with strong .
