ISCA Archive Interspeech 2014
ISCA Archive Interspeech 2014

Decorrelated innovative codebooks for ACELP using factorization of autocorrelation matrix

Tom Bäckström, Christian R. Helmrich

Modern speech codecs based on Code Excited Linear Prediction (CELP) employ an analysis-by-synthesis optimization loop to find the best quantization of the source model parameters. With this approach, optimal quantization can be achieved only with an exhaustive search. Instead, we propose to use matrix factorization to decorrelate the objective function of the optimization problem, whereby the computationally expensive iteration can be avoided and optimal performance is guaranteed. We compare two factorizations of the autocorrelation matrix, the eigenvalue decomposition and Vandermonde factorization. Our experiments show that decorrelation improves perceptual SNR and gives a large reduction in computational complexity, mostly without significant impact on subjective quality.


doi: 10.21437/Interspeech.2014-586

Cite as: Bäckström, T., Helmrich, C.R. (2014) Decorrelated innovative codebooks for ACELP using factorization of autocorrelation matrix. Proc. Interspeech 2014, 2794-2798, doi: 10.21437/Interspeech.2014-586

@inproceedings{backstrom14_interspeech,
  author={Tom Bäckström and Christian R. Helmrich},
  title={{Decorrelated innovative codebooks for ACELP using factorization of autocorrelation matrix}},
  year=2014,
  booktitle={Proc. Interspeech 2014},
  pages={2794--2798},
  doi={10.21437/Interspeech.2014-586},
  issn={2308-457X}
}