The application of the median LMS algorithm to ADPCM systems

Author

Givens, Maurice ; Clarkson, Peter M.

Author_Institution

Tellabs Inc., Lisle, IL, USA

fYear

1991

fDate

14-17 Apr 1991

Firstpage

3665

Abstract

The use of the median least-mean-square (MLMS) adaptive filter in adaptive differential pulse-code modulation (ADPCM) systems is examined. The MLMS is a modification of the LMS algorithm designed to protect the adaptive filter coefficients from the effects of impulsive noise. A modified MLMS-ADPCM system is proposed in which the MLMS replaces the LMS in the predictor updates. Objective SNR-based performance measures are used to compare MLMS with LMS in the context of a 32 kb/s system. It is shown that for ideal channels the performance of the MLMS-ADPCM is comparable to that of the conventional LMS-ADPCM. Using independent bit errors, it is shown that when the channel is degraded, MLMS outperforms LMS and appears to obviate the need for coefficient leakage in the predictor update

Keywords

digital communication systems; least squares approximations; pulse-code modulation; 32 kbit/s; MLMS-ADPCM system; SNR-based performance measures; adaptive differential pulse-code modulation; adaptive filter coefficients; digital communication systems; ideal channels; impulsive noise; independent bit errors; least mean squares approximation; median LMS algorithm; predictor updates; Adaptive filters; Algorithm design and analysis; Damping; Error correction; Filtering; Least squares approximation; Noise reduction; Nonlinear filters; Protection; Signal to noise ratio;

fLanguage

English

Publisher

ieee

Conference_Titel

Acoustics, Speech, and Signal Processing, 1991. ICASSP-91., 1991 International Conference on

Conference_Location

Toronto, Ont.

ISSN

1520-6149

Print_ISBN

0-7803-0003-3

Type

conf

DOI

10.1109/ICASSP.1991.151071

Filename

151071