Comparison of Adaptive Linear Prediction Algorithms in ADPCM

A comparison of adaptive differential pulse code modulation (ADPCM) speech compression systems is made using different recursive adaptive linear prediction algorithms. The particular algorithms considered are 1) a fixed predictor, 2) the adaptive least mean square (LMS) transversal predictor, 3) the LMS (gradient) lattice predictor, 4) the leas squares (LS) lattice predictor, and 5) an LS lattice predictor combined with a third-order pitch inverse filter. The results indicate that for the conditions simulated, the difference in system performance using the different adaptive algorithms is negligible, suggesting that the predictor having the simplest implementation is the best.