Title :
Modified LMS algorithms for robust ADPCM
Author :
Pesquet, J.C. ; Tziritas, G. ; Macchi, O.
Author_Institution :
Lab. des Signaux et Syst., ESE, Gif-sur-Yvette, France
Abstract :
The robustness of adaptive differential pulse code modulation (ADPCM) systems versus transmission errors is addressed. To secure the stability of the decoder, it is necessary to modify the form of the LMS (least-mean-square) algorithm used to adapt the predictor. Solutions introducing soft constraints are investigated. The leakage algorithm is proved to be not fully satisfactory, and a new stabilizing algorithm is presented that makes it possible to achieve good performances. Compared to existing methods, the main advantage of this algorithm is its low computational complexity. Form a theoretical point of view, the effect of transmission errors is described by a set of nonlinear recurrent equations. An analysis is carries out in the deterministic second-order case
Keywords :
computational complexity; filtering and prediction theory; least squares approximations; pulse-code modulation; adaptive differential pulse code modulation; deterministic second-order case; leakage algorithm; low computational complexity; modified LMS algorithm; modified least mean square algorithm; nonlinear recurrent equations; predictor; robust ADPCM; soft constraints; stabilizing algorithm; transmission errors; Computational complexity; Decoding; Image coding; Least squares approximation; Modulation coding; Nonlinear equations; Pulse compression methods; Pulse modulation; Robustness; Stability;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 1990. ICASSP-90., 1990 International Conference on
Conference_Location :
Albuquerque, NM
DOI :
10.1109/ICASSP.1990.115652
