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2012-12-11

PhD: Low Complexity Algorithms for Echo Cance.....

PhD: Low Complexity Algorithms for Echo Cancellation in Audio Conferencing Systems

Doktorand Christian Schüldt försvarar sin doktorsavhandling i ämnet Telekommunikation den 11 december.

Tid: 11 december 2012 kl. 13:00
Plats:
J1640, BTH, Campus Gräsvik, Karlskrona

Avhandlingens titel: Low Complexity Algorithms for Echo Cancellation in Audio Conferencing Systems

Forskarutbildningsämne: Telekommunikation

Huvudhandledare och examinator: Professor Ingvar Claesson, BTH

Ordförande: Professor Ingvar Claesson, BTH

Opponent: Tekn. dr Anders Eriksson, Ericsson Research, Ericsson AB, Stockholm, Sweden

Betygsnämnd:

  • Professor Peter Händel, School of Electrical Engineering, Signal Processing, KTH
  • Professor Sten Ternström, Music Acoustics Group at the Department of Speech, Music and Hearing, KTH
  • Dr Bengt Mandersson, Lunds universitet

Betygsnämndssuppleant: Docent Bo Schenkman, BTH

Anmälan om deltagande görs till administration BTH-ING senast den 1 december.

Länk till uppsatsen

Abstract:
Ever since the birth of the telephony system, the problem with echoes, arising from impedance mismatch in 2/4-wire hybrids, or acoustic echoes where a loudspeaker signal is picked up by a closely located microphone, has been ever present. The removal of these echoes is crucial in order to achieve an acceptable audio quality for conversation. Today, the perhaps most common way for echo removal is through cancellation, where an adaptive filter is used to produce an estimated replica of the echo which is then subtracted from the echo-infested signal.

Echo cancellation in practice requires extensive control of the filter adaptation process in order to obtain as rapid convergence as possible while also achieving robustness towards disturbances. Moreover, despite the rapid advancement in the computational capabilities of modern digital signal processors there is a constant demand for low-complexity solutions that can be implemented using low power and low cost hardware.

This thesis presents low-complexity solutions for echo cancellation related to both the actual filter adaptation process itself as well as for controlling the adaptation process in order to obtain a robust system. Extensive simulations and evaluations using real world recorded signals are used to demonstrate the performance of the proposed solutions.

 

 

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Sektionen för ingenjörsvetenskap

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