Performance bounds for LPC spectrum quantization

This paper presents a method for obtaining numerical estimates of high rate vector quantization (VQ) performance suitable for sources for which the PDF is not analytically available. In the proposed method, the VQ point density is described from a Gaussian mixture model optimized for the data. Employing this method for LPC spectrum quantization, we obtain high rate expressions for both the average spectral distortion (SD) and the distribution function of the SD. We estimate the minimum bits required for a quantizer to obtain an average SD of 1 dB and the outlier statistics for that quantizer. We find that approximately 3 bits can be saved as compared to a 2-split LSF-based vector quantizer.

[1]  Roar Hagen,et al.  Spectral quantization of cepstral coefficients , 1994, Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing.

[2]  Douglas A. Reynolds,et al.  Robust text-independent speaker identification using Gaussian mixture speaker models , 1995, IEEE Trans. Speech Audio Process..

[3]  Petter Knagenhjelm.  Competitive Learning in Robust Communication , 1993 .

[4]  D. Rubin,et al.  Maximum likelihood from incomplete data via the EM - algorithm plus discussions on the paper , 1977 .

[5]  David L. Neuhoff,et al.  Asymptotic distribution of the errors in scalar and vector quantizers , 1996, IEEE Trans. Inf. Theory.

[6]  R. Gray.  Source Coding Theory , 1989 .

[7]  Per Hedelin.  Single stage spectral quantization at 20 bits , 1994, Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing.

[8]  K. Paliwal,et al.  Efficient vector quantization of LPC parameters at 24 bits/frame , 1990 .

[9]  Allen Gersho,et al.  Vector quantization and signal compression , 1991, The Kluwer international series in engineering and computer science.

[10]  K. Paliwal,et al.  Quantization of LPC Parameters , 2022 .

[11]  Jan Skoglund.  From Modeling to Perception - Topics in Speech Coding , 1998 .

[12]  Bhaskar D. Rao,et al.  Theoretical analysis of the high-rate vector quantization of LPC parameters , 1995, IEEE Trans. Speech Audio Process..