Variable-dimension vector quantization of speech spectra for low-rate vocoders
- 17 December 2002
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- p. 420-429
- https://doi.org/10.1109/dcc.1994.305949
Abstract
Optimal vector quantization of variable-dimension vectors in principle is feasible by using a set of fixed dimension VQ codebooks. However, for typical applications, such a multi-codebook approach demands a grossly excessive and impractical storage and computational complexity. Efficient quantization of such variable-dimension spectral shape vectors is the most challenging and difficult encoding task required in an important family of low bit-rate vocoders. The authors introduce a simple and effective formulation of variable-dimension vector quantization (VDVQ) which quantizes variable-dimension vectors using a single universal codebook having fixed dimension yet covering the entire range of input vector dimensions under consideration. This VDVQ technique is applied to quantize variable-dimension spectral shape vectors leading to a high quality speech coder at the low bit-rate of 2.5 kb/s. The combination of a universal spectral codebook and structured VQ reduces storage and computational complexity, yet delivers a high quantization efficiency and enhanced perceptual quality of the coded speech.<>Keywords
This publication has 4 references indexed in Scilit:
- A 2400 bps multi-band excitation vocoderPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- The Dod 4.8 Kbps Standard (Proposed Federal Standard 1016)Published by Springer Nature ,1991
- Multiband excitation vocoderIEEE Transactions on Acoustics, Speech, and Signal Processing, 1988
- Speech analysis/Synthesis based on a sinusoidal representationIEEE Transactions on Acoustics, Speech, and Signal Processing, 1986