CONTENTS

 1     Background
 2     Overview of ADPCM algorithms
 3     Principles of Recommendations G.726 and G.727 and COM XVIII-102
        3.1     Adaptive Prediction and Reconstruction of the Signal
        3.2     Adaptive Quantizer
        3.3     Quantizer Scale Factor Adaptation
        3.4     Adaptation Speed Control
 4     Principles of COM XVIII-101
        4.1     Prediction
        4.2     The Fixed AR Filter
        4.3     Adaptive AR Filter
        4.4     Update Equations
        4.5     Quantizer Adaptation
 5     ADPCM Decoder
        5.1     General Description
        5.2     Synchronous Coding Adjustment
 6     Objective Evaluation of ADPCM
        6.1     Theoretical Background
        6.2     Performance of the ADPCM Algorithms for Voiceband Data
        6.3     Objective Measurements
 7     Subjective Evaluation of ADPCM
        7.1     Subjective Evaluation of 32 kbit/s ADPCM
        7.2     Subjective Evaluation of G.721 Extensions
        7.3     Subjective Evaluation of Embedded ADPCM
Appendix I
References