Echo Cancellation Using Sparse Tap Adaptive Fir Filter PDF Download

Author: Madan M. Bijili
Publisher:
ISBN:
Category :
Languages : en
Pages : 122

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Author: Constantin Paleologu
Publisher: Springer Nature
ISBN: 3031025598
Category : Technology & Engineering
Languages : en
Pages : 114

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Book Description
Adaptive filters with a large number of coefficients are usually involved in both network and acoustic echo cancellation. Consequently, it is important to improve the convergence rate and tracking of the conventional algorithms used for these applications. This can be achieved by exploiting the sparseness character of the echo paths. Identification of sparse impulse responses was addressed mainly in the last decade with the development of the so-called ``proportionate''-type algorithms. The goal of this book is to present the most important sparse adaptive filters developed for echo cancellation. Besides a comprehensive review of the basic proportionate-type algorithms, we also present some of the latest developments in the field and propose some new solutions for further performance improvement, e.g., variable step-size versions and novel proportionate-type affine projection algorithms. An experimental study is also provided in order to compare many sparse adaptive filters in different echo cancellation scenarios. Table of Contents: Introduction / Sparseness Measures / Performance Measures / Wiener and Basic Adaptive Filters / Basic Proportionate-Type NLMS Adaptive Filters / The Exponentiated Gradient Algorithms / The Mu-Law PNLMS and Other PNLMS-Type Algorithms / Variable Step-Size PNLMS Algorithms / Proportionate Affine Projection Algorithms / Experimental Study

Author: Patrick Kechichian
Publisher:
ISBN:
Category :
Languages : en
Pages : 105

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"The focus of this thesis is twofold. First, it analyzes the partial Haar echo canceller and attempts to clarify some issues with its implementation. Second and foremost, it, identifies and proposes feasible solutions to three inherent weaknesses of the coupled echo canceller. These include alleviating the adverse effect caused by the shift-variant property of wavelets, improving the tracking performance of the coupled echo canceller in response to abrupt changes in the echo path impulse response, and extending the original echo canceller to support the cancellation of multiple echoes. Simulations support the resulting improvements when each of the proposed solutions is incorporated into the coupled echo canceller." --

Author: Jacob Benesty
Publisher: Springer Science & Business Media
ISBN: 3642225748
Category : Technology & Engineering
Languages : en
Pages : 141

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Book Description
Single-channel hands-free teleconferencing systems are becoming popular. In order to enhance the communication quality of these systems, more and more stereophonic sound devices with two loudspeakers and two microphones are deployed. Because of the coupling between loudspeakers and microphones, there may be strong echoes, which make real-time communication very difficult. The best way we know to cancel these echoes is via a stereo acoustic echo canceller (SAEC), which can be modelled as a two-input/two-output system with real random variables. In this work, the authors recast this problem into a single-input/single-output system with complex random variables thanks to the widely linear model. From this new convenient formulation, they re-derive the most important aspects of a SAEC, including identification of the echo paths with adaptive filters, double-talk detection, and suppression.

Author: J. Benesty
Publisher: Springer Science & Business Media
ISBN: 3662044374
Category : Technology & Engineering
Languages : en
Pages : 232

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Book Description
This book brings together many advanced topics in network and acoustic echo cancellation aimed towards enhancing the echo cancellation performance of next-generation telecommunication systems. The resulting compendium provides a coherent treatment of such topics not found otherwise in journals or other books.

Author: Michael Oliver Vukadinovic
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Hands-free communication techniques are becoming increasingly important in the world of modern telephony. The convenience of hands-free links is invaluable in teleconferencing situations, automobiles and even in personal communications. The loud-speaker and microphone on a hands-free set are inherently coupled acoustically, producing an echo which degrades the quality of conversation over such a link. The conventional acoustic echo cancellation method is gain control which provides a half-duplex communication link. Research into adaptive filters which can provide a full-duplex communication link is intense but transparent transmission of speech over a hands-free link remains an elusive goal. Conventional acoustic echo cancellers are concerned with minimizing an objective measure of the level of echo. This thesis presents a study of two adaptive filtering structures which are based on the goal of providing the best subjective echo cancellation possible. The adaptive filtering algorithms attempt to give the echo the same spectral shape as the absolute hearing threshold curve, in order to minimize the echo's audibility. The filtered-E LMS algorithm, considered first, was found not to perform the kind of frequency weighting desired. A proposed subband adaptive filter with perceptually-based adaptive tap assignment, when trained with natural speech, is capable of providing a noticeable improvement in audible echo cancellation; however, when trained with bandlimited speech, the algorithm's performance was found to be only slightly better or comparable to the fixed tap assignment algorithm in terms of audible echo cancellation. The subband adaptive filtering algorithm is evaluated by means of simple listening tests performed by the author.

Author: Simon Haykin
Publisher: John Wiley & Sons
ISBN: 9780471215707
Category : Technology & Engineering
Languages : en
Pages : 516

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Edited by the original inventor of the technology. Includes contributions by the foremost experts in the field. The only book to cover these topics together.

Author: Veeratej Garre
Publisher: LAP Lambert Academic Publishing
ISBN: 9783659311543
Category :
Languages : en
Pages : 76

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Book Description
Acoustic echo is a common occurrence in today's telecommunication systems. The distraction caused by the acoustic echo, reduces the speech quality in the communication. In the communication system acoustic echo cancelers is works as the far-end signal is delivered to the system, it will be reproduced by the loudspeaker in the room. A microphone in the room picks up the resulting direct path sound and consequent reverberation sound as a near-end signal. The reverberated signal is estimated by the adaptive filter and cancelled from the microphone signal. The AEC with adaptive filtering technique will more accurately enhance the speech quality in hands-free and teleconferencing systems. There are many adaptive algorithms available in the literature for echo cancellation and every algorithm have its own properties, but the aim of algorithms using for echo cancellation is to achieve higher ERLE(amount of echo cancelled)at a higher rate of convergence with low complexity.The performance evaluation of the NLMS, APA and RLS in AEC are discussed in this book.

Author: Sebastian Miron
Publisher: BoD – Books on Demand
ISBN: 9537619915
Category : Computers
Languages : en
Pages : 540

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Book Description
This book intends to provide highlights of the current research in signal processing area and to offer a snapshot of the recent advances in this field. This work is mainly destined to researchers in the signal processing related areas but it is also accessible to anyone with a scientific background desiring to have an up-to-date overview of this domain. The twenty-five chapters present methodological advances and recent applications of signal processing algorithms in various domains as telecommunications, array processing, biology, cryptography, image and speech processing. The methodologies illustrated in this book, such as sparse signal recovery, are hot topics in the signal processing community at this moment. The editor would like to thank all the authors for their excellent contributions in different areas of signal processing and hopes that this book will be of valuable help to the readers.

Author: Lino Garcia Morales
Publisher: BoD – Books on Demand
ISBN: 9533071583
Category : Computers
Languages : en
Pages : 414

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Book Description
Adaptive filtering is useful in any application where the signals or the modeled system vary over time. The configuration of the system and, in particular, the position where the adaptive processor is placed generate different areas or application fields such as prediction, system identification and modeling, equalization, cancellation of interference, etc., which are very important in many disciplines such as control systems, communications, signal processing, acoustics, voice, sound and image, etc. The book consists of noise and echo cancellation, medical applications, communications systems and others hardly joined by their heterogeneity. Each application is a case study with rigor that shows weakness/strength of the method used, assesses its suitability and suggests new forms and areas of use. The problems are becoming increasingly complex and applications must be adapted to solve them. The adaptive filters have proven to be useful in these environments of multiple input/output, variant-time behaviors, and long and complex transfer functions effectively, but fundamentally they still have to evolve. This book is a demonstration of this and a small illustration of everything that is to come.