Reduced complexity echo cancellation using orthonormal functions

Author

Davidson, Gordon W. ; Falconer, David D.

Author_Institution

Carleton Univ., Ottawa, Ont., Canada

Volume

38

Issue

1

fYear

1991

fDate

1/1/1991 12:00:00 AM

Firstpage

20

Lastpage

28

Abstract

Top reduce the echo canceler complexity associated with the cancellations of subscriber loop echo responses with long tails, a two-stage digital echo canceler, in which the second stage is an adaptively weighted combination of orthonormal IIR responses is proposed and investigated. Satisfactory performance (70-dB cancellation) was found for a variety of loops at 80 and 320 kB symbol rates with 15 such IIR responses, based on a Laguerre functions. The first echo canceler stage is a conventional transversal filter with 20-40 tap coefficients. Substantial complexity reduction was achieved by the new structure. Adaptation convergence was also analyzed and simulated

Keywords

adaptive filters; convergence; digital filters; echo suppression; filtering and prediction theory; signal processing; Laguerre functions; adaptation convergence; adaptively weighted combination; complexity reduction; echo cancellation; infinite impulse response; orthonormal IIR responses; orthonormal functions; subscriber loop echo responses; transversal filter; two-stage digital echo canceler; Bit rate; Convergence; Crosstalk; Echo cancellers; Finite impulse response filter; IIR filters; Probability distribution; Subscriber loops; Tail; Transversal filters;

fLanguage

English

Journal_Title

Circuits and Systems, IEEE Transactions on

Publisher

ieee

ISSN

0098-4094

Type

jour

DOI

10.1109/31.101300

Filename

101300