Adaptive Polynomial Filters and their Application to Nonlinear Acoustic Echo Cancellation

Thesis
(Dissertation)


Publication Details

Author(s): Küch F
Publisher: University Erlangen-Nuremberg
Publishing place: Erlangen
Publication year: 2005
Language: English


Abstract

In todays telecommunication devices often cheap audio hardware is
included which introduces non-negligible nonlinear distortion into the
loudspeaker signal. In case of hands-free telephone systems or mobile
communication devices, these nonlinear audio components cause
nonlinearly distorted acoustic echoes that can not be sufficiently
attenuated by purely linear echo cancellers. This application
exemplifies the growing demand for nonlinear adaptive signal processing
methods. In this work, we address the task to provide nonlinear adaptive
algorithms for applications in acoustic echo cancellation in order to
overcome performance limitations of linear approaches. Based on a
nonlinear discrete-time model for the acoustic echo path, we focus on
special types of adaptive polynomial filters which require only little a
priori knowledge about the audio hardware actually included in the
telecommunication device. If moderately-sized loudspeakers represent the
only source of nonlinear distortion, second-order Volterra filters can
been used to model their frequency-dependent nonlinear behaviour.
Additionally, we consider the case that only the amplifier or the
miniaturized loudspeaker of a mobile phone causes the nonlinear
distortion in the echo path. For this scenario, an orthogonalized
version of adaptive power filters is proposed in order to improve the
echo cancellation performance compared to purely linear approaches in
case of saturation-type nonlinearities included in the echo path.
Experimental results obtained for real loudspeaker systems are presented
in order to verify the suitability of the discussed nonlinear adaptive
algorithms for nonlinear acoustic echo cancellation.


How to cite

APA:
Küch, F. (2005). Adaptive Polynomial Filters and their Application to Nonlinear Acoustic Echo Cancellation (Dissertation).

MLA:
Küch, Fabian. Adaptive Polynomial Filters and their Application to Nonlinear Acoustic Echo Cancellation. Dissertation, Erlangen: University Erlangen-Nuremberg, 2005.

BibTeX: 

Last updated on 2019-02-06 at 18:31