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Stereophonic Acoustic Echo Cancellation: Theory and Implementation

Eneroth, Peter LU (2001)
Abstract
The thesis treats theory and implementation aspects for stereophonic acoustic echo cancellation.



In Paper I a complete implementation of a stereophonic acoustic echo canceler based on the two-channel fast recursive least-squares algorithm is presented. An analysis of the system calculation complexity is also given, in addition to simulation results on recorded real-life data.



Paper II presents a comparison between adaptive filters for usage in stereophonic acoustic echo cancellation. The comparison includes, in addition to the standard normalized least mean square algorithm, the two-channel fast recursive least-squares algorithm and a two-channel frequency-domain adaptive algorithm. In the paper, the... (More)
The thesis treats theory and implementation aspects for stereophonic acoustic echo cancellation.



In Paper I a complete implementation of a stereophonic acoustic echo canceler based on the two-channel fast recursive least-squares algorithm is presented. An analysis of the system calculation complexity is also given, in addition to simulation results on recorded real-life data.



Paper II presents a comparison between adaptive filters for usage in stereophonic acoustic echo cancellation. The comparison includes, in addition to the standard normalized least mean square algorithm, the two-channel fast recursive least-squares algorithm and a two-channel frequency-domain adaptive algorithm. In the paper, the convergence rate, the calculation complexity, the signal transmission delay, and the memory usage for the evaluated systems are shown.



Adaptive filters applied in subband structures may need to model a few non-causal taps even if the fullband impulse response is causal. This phenomenon is analyzed in Paper III. Formulas to calculate the number of non-causal taps needed are also presented in the paper.



The fundamental problem in stereophonic acoustic echo cancellation is the signal correlation between the two channels. In Paper IV it is shown how a perceptual audio coder may decrease this correlation and thereby increase the performance of the stereophonic acoustic echo canceler.



Paper V investigates the possibilities of using joint subband filterbanks or time to frequency-domain transforms for echo cancellation and perceptual audio coding. The usage of joint filterbanks/transforms not only decreases the computational complexity of the system, it also reduces the total signal transmission delay of the system if properly designed. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Doc Händel, Peter, KTH, Sweden
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Stereophonic Acoustic Echo Cancellation, Filterbank, Two-Channel Fast RLS, Two-Channel Frequency-Domain Adaptive filtering, NLMS, Electronics and Electrical technology, Audio Coding, Elektronik och elektroteknik, Signal processing, Signalbehandling, Subband
pages
175 pages
publisher
Department of Electroscience, Lund University
defense location
E:1406, E-huset, LTH
defense date
2001-02-09 13:15
ISSN
1402-8662
ISBN
91-7874-110-6
language
English
LU publication?
yes
id
65ec86a9-1534-4165-a26c-bbc374448acf (old id 41259)
date added to LUP
2007-06-21 10:19:04
date last changed
2018-05-29 12:01:16
@phdthesis{65ec86a9-1534-4165-a26c-bbc374448acf,
  abstract     = {The thesis treats theory and implementation aspects for stereophonic acoustic echo cancellation.<br/><br>
<br/><br>
In Paper I a complete implementation of a stereophonic acoustic echo canceler based on the two-channel fast recursive least-squares algorithm is presented. An analysis of the system calculation complexity is also given, in addition to simulation results on recorded real-life data.<br/><br>
<br/><br>
Paper II presents a comparison between adaptive filters for usage in stereophonic acoustic echo cancellation. The comparison includes, in addition to the standard normalized least mean square algorithm, the two-channel fast recursive least-squares algorithm and a two-channel frequency-domain adaptive algorithm. In the paper, the convergence rate, the calculation complexity, the signal transmission delay, and the memory usage for the evaluated systems are shown.<br/><br>
<br/><br>
Adaptive filters applied in subband structures may need to model a few non-causal taps even if the fullband impulse response is causal. This phenomenon is analyzed in Paper III. Formulas to calculate the number of non-causal taps needed are also presented in the paper.<br/><br>
<br/><br>
The fundamental problem in stereophonic acoustic echo cancellation is the signal correlation between the two channels. In Paper IV it is shown how a perceptual audio coder may decrease this correlation and thereby increase the performance of the stereophonic acoustic echo canceler.<br/><br>
<br/><br>
Paper V investigates the possibilities of using joint subband filterbanks or time to frequency-domain transforms for echo cancellation and perceptual audio coding. The usage of joint filterbanks/transforms not only decreases the computational complexity of the system, it also reduces the total signal transmission delay of the system if properly designed.},
  author       = {Eneroth, Peter},
  isbn         = {91-7874-110-6},
  issn         = {1402-8662},
  keyword      = {Stereophonic Acoustic Echo Cancellation,Filterbank,Two-Channel Fast RLS,Two-Channel Frequency-Domain Adaptive filtering,NLMS,Electronics and Electrical technology,Audio Coding,Elektronik och elektroteknik,Signal processing,Signalbehandling,Subband},
  language     = {eng},
  pages        = {175},
  publisher    = {Department of Electroscience, Lund University},
  school       = {Lund University},
  title        = {Stereophonic Acoustic Echo Cancellation: Theory and Implementation},
  year         = {2001},
}