Title :
Reduced complexity echo cancellation using orthonormal functions
Author :
Davidson, Gordon W. ; Falconer, David D.
Author_Institution :
Carleton Univ., Ottawa, Ont., Canada
fDate :
1/1/1991 12:00:00 AM
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;
Journal_Title :
Circuits and Systems, IEEE Transactions on
