Subband splitting, adaptive scalar prediction and vector quantization for speech coding

Abstract

This paper describes a new coding structure based on the combination of Vector Quantizati.on, Linear Prediction l)nd Subband Splitting that achieves high guality speech at rates below 10 Kbit/sec. In this scheme, a vector is formed with one sanple of the normalized prediction error of each band and then a vector quanti.zer is applied to it. This guantization of the prediction error a.llows to use scalar adaptive predictors while conserving the advantages of the vector guantization. The necessary noise shap~ for achjev:ing high subjective quality is obtained by the use of a Freguency-Weighted distance in thc vecto r guantizer