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Code-excited linear prediction

About: Code-excited linear prediction is a research topic. Over the lifetime, 2025 publications have been published within this topic receiving 28633 citations. The topic is also known as: CELP.


Papers
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Proceedings ArticleDOI
08 Sep 1998
TL;DR: The efficiency and reliability of the proposed algorithm are improved using the interlacing property of the LSPs and knowledge of the direction of the sign-change at every zero-crossing, and it is compared with the existing Kabal's algorithm (followed by quantization), showing similar quantization performance.
Abstract: Line Spectrum Pair (LSP) representation is used for spectral quantization in the CELP FS1016 speech coder, where the LSPs are first calculated, and then quantized using 34-bit non-uniform scalar quantization. In the algorithm proposed in this paper, computational complexity is decreased by searching the zero-crossings on the grid formed by the values of the quantization tables. As the actual LSPs are not calculated, two criteria to select the "closest" quantized LSPs are proposed. These criteria take into account the interaction between successive LSPs. The efficiency and reliability of the proposed algorithm are improved using the interlacing property of the LSPs and knowledge of the direction of the sign-change at every zero-crossing. The proposed algorithm is compared with the existing Kabal's algorithm (followed by quantization), showing similar quantization performance. The computational complexity on a fixed-point DSP56001 implementation is reduced by 66 %, using the proposed algorithm.

3 citations

Proceedings ArticleDOI
18 Sep 2003
TL;DR: A new approach based on energy-adaptive matching pursuits to improve sinusoidal modelling for parametric speech and audio coding is proposed, and an over-complete dictionary composed of complex exponentials is used.
Abstract: In this paper we propose a new approach based on energy-adaptive matching pursuits to improve sinusoidal modelling for parametric speech and audio coding. To reduce the complexity of the algorithm, an over-complete dictionary composed of complex exponentials is used. An analysis-synthesis windows scheme that avoids overlapping is proposed. For efficient quantization of sinusoidal model parameters, a new algorithm that largely reduces the side information required by the decoder is described. Experimental results show evidence of the advantages of the proposed method to be integrated into multi-pans models for parametric speech/audio coding.

3 citations

Patent
13 Jun 2007
TL;DR: In this paper, a fixed codebook searching apparatus and method in a CELP-based speech coder are provided to select an initial codebook suitable for a speech characteristic and decide the number of pulse replacements and a limit in order to improve sound quality and reduce the quantity of unnecessary calculations.
Abstract: A fixed codebook searching apparatus and method in a CELP(Code Excited Linear Prediction)-based speech coder are provided to select an initial fixed codebook suitable for a speech characteristic and decide the number of pulse replacements and a limit in order to improve sound quality and reduce the quantity of unnecessary calculations. A fixed codebook searching apparatus in a CELP-based speech coder includes a speech characteristic information collection unit(310), a speech characteristic determination unit(320), an initial fixed codebook determination unit(330), a fixed codebook search parameter determination unit(340), and a fixed codebook determination unit(350). The speech characteristic information collection unit collects speech information from user's speech by using a CELP speech coder. The speech characteristic determination unit determines a speech characteristic based on the collected speech information. The initial fixed codebook determination unit selects an initial fixed codebook based on the determined speech characteristic. The fixed codebook search parameter determination unit determines various constants required for pulse replacement based on the determined speech characteristic. The fixed codebook determination unit determines a fixed codebook through the pulse replacement by using the selected fixed codebook search parameter and the initial fixed codebook as initial values.

3 citations

Journal ArticleDOI
TL;DR: An insight to the capabilities of compressive sensing (CS) in speech processing and a novel idea in the quantized framework is provided and the results indicate that the proposed scheme offers better compression in comparison with basic Gaussian codebook CELP.
Abstract: Speech compression or speech coding is inevitable for effective communication of speech signals in resource limited scenarios and researcher’s have been working on achieving lower and lower transmission bit rates (BR) without much compromise on the quality of speech Medium BR hybrid speech coding schemes have gained much interest in the recent years with most of them based on CELP, the basic medium bit-rate coding scheme In this work, we provide an insight to the capabilities of compressive sensing (CS) in speech processing and propose a novel idea in the quantized framework Three major aspects demonstrated in this paper are (1) Inherent de-noising of noisy speech by the CS based coder along with compression (2) Quantization of CS measurements to achieve medium transmission bit-rates and (3) Enhancement of quality and compression performance of the coder with better sparse representations of speech using dictionaries The results indicate that the proposed scheme offers better compression in comparison with basic Gaussian codebook CELP The CS scheme has the added advantage of inherent noise suppression and provides more robustness to background noise in comparison with parameter extraction based medium bit-rate speech coding systems

3 citations

Proceedings ArticleDOI
09 Jun 1997
TL;DR: The fixed-point accuracy analysis and VLSI architecture of FS1O16 CELP decoder are presented and the specification satisfying the FS1016 CelP coder is presented.
Abstract: In this paper, the fixed-point accuracy analysis and VLSI architecture of FS1O16 CELP decoder are presented. The code excited linear predictive (CELP) coder is the most effective technique among various linear predictive coding methods for speech compression. Hence to design a low cost and low power CELP decoder chip for the portable systems and wireless digital communication environment becomes increasingly important. The decoder VLSI architecture can achieve (1) excellent accuracy results due to the accuracy studies for the finite word length, (2) power saving and high speed operations resulting from the combined advantages of pipeline, current processing for LSE's interpolating and cosine operation, (3) table size reducing by applying the memoryless realization for stochastic codebook and partial sums technique, and (4) specification satisfying the FS1016 CELP coder.

3 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20226
20213
20207
201915
201810
201713