Quantisation Techniques for Prototype Waveforms

Abstract

Speech coders based on Prototype Waveform techniques can produce speech at rates as low as 2.4kbIs. These coders represent the speech residual by a series of pitch length characteristic or prototype waveform which are aligned and interpolated to rcumstruct the excitation at the receiver. The Prototype Waveforms can be decomposed into noisy and periodic components for quantisation. This paper examines the different quantisation requirements of these two distinct, variable-length vector components and describes codebook solutions leading to near-Toll quality Multi-Rototype Waveform coders at bit-rates from 2.4 to4kbIs.