Acoustic echo cancellation is one of the oldest applications of the adaptive filters and today part of each speakerphone. An important block of each acoustic echo canceller is the double talk detector. It blocks the adaptation of the filter when near end voice is present and thus preventing the adaptive filter from diverging from the optimal position. In this paper we present an improved versio...

Adaptive ltering has been successfully used in canceling line echos in the telephone network since the 1960's [179, 443, 387]. In these cases, the adaptive lter is used to model the unknown echo path in a communications channel and then cancel the echo signals from the conversation. An adaptive lter is required because the echo path is not only unknown, but also because it is di erent for each ...

A method of using Interrupted-Sampling Repeater Jamming (ISRJ) to cancel radar target echo is proposed. After the principles of ISRJ are expounded, three conditions that should be met for radar echo cancellation are proposed, including range synchronization, phase coherent and amplitude match. Then, the restriction for key parameters of ISRJ, i.e. the repeater power, the delay time and frequenc...

A novel algorithm for use in stereophonic acoustic echo cancellation is introduced. The alternating fixed-point structure of the algorithm descends each of the channels alternatively and avoids nonuniqueness in the solutions by employing interand intra-channel orthogonal projections. For a noisy environment, the algorithm is shown to provide improved misalignment performance and echo cancellati...

We describe a combined nonlinear acoustic echo cancellation and residual echo suppression system. The echo canceler uses parallel Hammerstein branches consisting of fixed nonlinear basis functions and linear adaptive filters. The residual echo suppressor uses an Artificial Neural Network for modeling of the residual echo spectrum from spectral features computed from the far-end signal. We show ...

Visualization of the cooperation context is an important issue, especially when applied to complex and unstable collective activities, as it is the case in the field of Architecture, Engineering and Construction (AEC). With the aim of assisting cooperative construction projects it is important to propose business services and user views adapted to user’s business requirements. This paper presen...

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Stereophonic acoustic echo cancellation has been found more difficult than echo cancellation in mono due to a high correlation between the two audio channels. Different methods to decorrelate the channels have been proposed so that the stereophonic echo canceller identifies the true echo paths and its convergence rate increases. In this paper it is shown that the use of a perceptual audio coder...

An overview of acoustic echo cancellation systems is presented. First the basics of echo’s, type of echo’s , why echo canceller are required and what are the difference between echo canceller are explained then the application where they can be used is discussed.. This paper presents applications of acoustic echo control and shows most recent solutions. For some selected applications (LEM) resu...

A new acoustic echo cancellation method for noisy environment is proposed and a real-time system is built. Different from the conventional acoustic echo cancellers, the proposed has a novel structure and can remove the echo effectively at low SNR. In our system, the speech with stationary noise is processed in order to separate the echo from the noise before updating the adaptive filter which i...