Nonsquare transform vector quantization

Lupini, P.; Cuperman, V.

doi:10.1109/97.475819

Cited by 11 publications

(3 citation statements)

References 5 publications

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“…We therefore selected the optimum numbers for the spectrum magnitude and phase as 15 and 8 in the first enhancement layer 1 and 30 and 16 in the second enhancement layer, respectively. By measuring the spectral distortion (SD) (Lupini and Cuperman 1996), it is possible to compare two structures, namely multi-stage VQ both with and without DCT. The results are described in Table 4.…”

Section: Figmentioning

confidence: 99%

Embedded bandwidth scalable wideband codec using hybrid matching pursuit harmonic/CELP scheme

et al. 2010

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Recent advances in speech coding have made wideband coding feasible at the bit-rates sufficient for mobile communication. Here we propose a novel hybrid harmocic Code Excited Linear Prediction (CELP) scheme for highband coding of band-split scalable wideband codec, where the low-band (0-4 kHz) is critically subsampled and coded selectively using existing narrowband codecs such as 5.4 kbps and 6.3 kbps G.723.1, 8 kbps G.729, and 11.8 kbps G.729E. The high-band signal is divided into stationary mode (SM) and non-stationary mode (NSM) components based on its unique characteristics. In the SM portion, the highband signal is compressed using a multi-stage coding that combines the sinusoidal model and CELP. The first stage coding applies the damping factor matching pursuit (MP) algorithm without either the Over-Lap-Add (OLA) or smoothly interpolative synthesis schemes and the second stage utilizes CELP with the circular codebook. In the NSM portion, the high-band signals are coded by CELP with both pulse and circular codebooks by applying the complexity-reduced algorithm. To ensure scalability in highband coding, two enhancement layers are used to increase the number of pulses and control the quantizing sinusoidal parameter numbers. This paper describes the new algorithm and discuses novel techniques for efficient bandwidth wideband speech coding and subjective quality performance. For efficient bit allocation and enhanced performance, the pitch of the high-band codec is estimated using the quantized pitch parameter in low-band codec. An informal listening test, rated the subjective speech quality as comparable to that obtainable with G.722.2 as the fullband wideband codec and G.722.2 as the highband codec, the recent standardized band-split wideband codec.

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Section: Figmentioning

confidence: 99%

Embedded bandwidth scalable wideband codec using hybrid matching pursuit harmonic/CELP scheme

et al. 2010

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“…with A N an N × M matrix. The described approach is known as nonsquare transform [14,15], and optimality criterion can be found for the matrices A N and B N . Similar to the case of partial quantization, the method is more suitable for low dimension, since the transformation process introduces losses that are not reversible.…”

Section: Variable-to-fixed-dimension Conversion Via Interpolation or mentioning

confidence: 99%

Vector Quantization of Harmonic Magnitudes in Speech Coding Applications—A Survey and New Technique

Chu¹

2004

EURASIP J. Adv. Signal Process.

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A harmonic coder extracts the harmonic components of a signal and represents them efficiently using a few parameters. The principles of harmonic coding have become quite successful and several standardized speech and audio coders are based on it. One of the key issues in harmonic coder design is in the quantization of harmonic magnitudes, where many propositions have appeared in the literature. The objective of this paper is to provide a survey of the various techniques that have appeared in the literature for vector quantization of harmonic magnitudes, with emphasis on those adopted by the major speech coding standards; these include constant magnitude approximation, partial quantization, dimension conversion, and variable-dimension vector quantization (VDVQ). In addition, a refined VDVQ technique is proposed where experimental data are provided to demonstrate its effectiveness.

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“…The discipline of variable dimension quantization, it appears, has not gained much attention. Though, in [6], a method for variable dimension quantization was proposed and then in [7], this method was applied to the problem of quantization of sinusoidal parameters for speech coding. Specifically, this was done by a variable-tofixed dimension transform followed by quantization.…”

Section: Introductionmentioning

confidence: 99%

Variable Dimension Trellis-Coded Quantization of Sinusoidal Parameters

Larsen

Christensen

Jensen

2008

IEEE Signal Process. Lett.

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Abstract-In this letter, we propose joint quantization of the parameters of a set of sinusoids based on the theory of trellis-coded quantization. A particular advantage of this approach is that it allows for joint quantization of a variable number of sinusoids, which is particularly relevant in variable rate parametric audio coding. Under high-resolution assumptions and based on a perceptually relevant distortion measure, we derive analytical expressions for the optimal design subject to an entropy constraint. Numerical experiments show a significant performance gain compared to optimal spherical quantization at the cost of a slight increase in computational complexity.

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Nonsquare transform vector quantization

Cited by 11 publications

References 5 publications

Embedded bandwidth scalable wideband codec using hybrid matching pursuit harmonic/CELP scheme

Embedded bandwidth scalable wideband codec using hybrid matching pursuit harmonic/CELP scheme

Vector Quantization of Harmonic Magnitudes in Speech Coding Applications—A Survey and New Technique

Variable Dimension Trellis-Coded Quantization of Sinusoidal Parameters

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