Patent
Code excited linear prediction speech coding system
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TLDR
In this article, a code excited linear prediction (CELP) type speech signal coding system is provided, a code vector obtained by applying linear prediction to a vector of a residual speech signal of white noise is stored in a code book.Abstract:
A code excited linear prediction (CELP) type speech signal coding system is provided, a code vector obtained by applying linear prediction to a vector of a residual speech signal of white noise is stored in a code book. A pitch prediction vector obtained by applying linear prediction to a residual signal of a preceding frame is given a delay corresponding to a pitch frequency and added to the code vector. Use is made of an impulse vector obtained by applying linear prediction to a residual signal vector of impulses having a predetermined relationship with the vectors of the white noise code book. Variable gains are given to at least the above code vector and impulse vector, a reproduced signal is produced, and this reproduced signal is used for identification of the input speech signal. Thus, a pulse series corresponding to the sound source of voiced speech sounds is created.read more
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References
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Proceedings ArticleDOI
Code-excited linear prediction(CELP): High-quality speech at very low bit rates
Manfred R. Schroeder,B. S. Atal +1 more
TL;DR: A code-excited linear predictive coder in which the optimum innovation sequence is selected from a code book of stored sequences to optimize a given fidelity criterion, indicating that a random code book has a slight speech quality advantage at low bit rates.
Patent
Predictive coding of speech signals
TL;DR: In this article, an adaptive predictor is employed which is readjusted periodically to match the time-varying characteristics of a speech signal, which is used to reduce the channel capacity required to transmit a signal with specified fidelity.
Proceedings ArticleDOI
Complexity reduction methods for vector excitation coding
G. Davidson,Allen Gersho +1 more
TL;DR: This paper presents several schemes in this paper which substantially reduce search computation in VXC coders while retaining their remarkably high reconstructed speech quality.
PatentDOI
Digital speech coder having improved vector excitation source
TL;DR: In this article, an improved vector generation and search technique was described for a code-excited linear prediction (CELP) speech coder using a codebook of excitation code vectors.
Patent
Vector excitation speech or audio coder for transmission or storage
Grant Davidson,Allen Gersho +1 more
TL;DR: In this paper, a vector excitation coder efficiently com-presses vectors by using an optimum codebook designed off-line, using an initial arbitrary codebook and a set of speech training vectors exploiting codevector sparsity.