Signal modification for ADPCM based on analysis-by-synthesis framework

Abstract

In this letter, we propose a novel approach to improve the performance of the adaptive differential pulse code modulation (ADPCM) codec by modifying the input signal under the analysis-by-synthesis framework. Modification of the input signal is performed such that the ADPCM codec causes less quantization error. When applied to the ITU-T G.726 ADPCM coder, the proposed algorithm improves the output signal-to-noise ratio up to 2.39 dB.