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US5664053A
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Predictive split-matrix quantization of spectral parameters for efficient coding of speech
Assignee: Université de Sherbrooke
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Filing: 1995-04-03
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Granted: 1997-09-02
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Expires: 2015-04-03
Abstract
Abstract The present invention concerns efficient quantization of more than one LPC spectral models per frame in order to enhance the accuracy of the time-varying spectrum representation without compromising on the coding-rate. Such efficient representation of LPC spectral models is advantageous to a number of techniques used for digital encoding of speech and/or audio signals.
Inventors
- 👤 Claude Laflamme
- 👤 Redman Salami
- 👤 Jean-Pierre Adoul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:35
CPC Classifications
G; G10; G10L; G10L19/00; G10L19/04; G10L19/06; G10L2019/0001; G10L2019/0004
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
94 words
A method for jointly quantizing N linear-predictive-coding spectral models per frame of a sampled sound signal, in which N>1, in view of enhancing a spectral-accuracy/coding-rate trade-off in a technique for digitally encoding said sound signal, said method comprising the following combination of steps: (a) forming a matrix, F, comprising N rows defining N vectors representative of said N linear-predictive-coding spectral models, respectively; (b) removing from the matrix F a time-varying prediction matrix, P, based on at least one previous frame, to obtain a residual matrix, R; and (c) vector quantizing said residual matrix R.
Claim 2
Independent Claim
94 words
A method for jointly quantizing N linear-predictive-coding spectral models per frame of a sampled sound signal, in which N>1, in view of enhancing a spectral-accuracy/coding-rate trade-off in a technique for digitally encoding said sound signal, said method comprising the following combination of steps: (a) forming a matrix, F, comprising N rows defining N vectors representative of said N linear-predictive-coding spectral models, respectively; (b) removing from the matrix F a time-varying prediction matrix, P, based on at least one previous frame, to obtain a residual matrix, R; and (c) vector quantizing said residual matrix R.
Claim 3
Dependent Claim
47 words
A method as defined in claim 1, wherein, to reduce the complexity of vector quantizing said residual matrix R, step (c) comprises the steps of partitioning said residual matrix R into a number of q sub matrices, having N rows, and vector quantizing independently each sub matrix.
Claim 4
Dependent Claim
22 words
A method as defined in claim 1, comprising the step of obtaining said time-varying prediction matrix P using a non-recursive prediction approach.
Claim 5
Dependent Claim
76 words
A method as defined in claim 3, wherein said non-recursive prediction approach consists of calculating the time-varying prediction matrix P according to the following formula, P=A R.sub.b ' where A is a Mxb matrix, M and b being integers, whose components are scalar prediction coefficients and where R b ' is a bxM matrix composed of the last b rows of a matrix, R', resulting from vector quantizing the residual matrix R of the previous frame.
Claim 6
Dependent Claim
50 words
A method as defined in claim 1, wherein said N linear-predictive-coding spectral models per frame correspond to N sub frames interspersed with m-1 sub frames, m being an integer, and wherein said vectors representative of said linear-predictive-coding spectral models corresponding to said interspersed sub frames are obtained using linear interpolation.
Claim 7
Dependent Claim
23 words
A method as defined in claim 1, further comprising the step of obtaining the time-varying prediction matrix P using a recursive prediction approach.
Claim 8
Dependent Claim
36 words
A method as defined in claim 1, wherein said N linear-predictive-coding spectral models per frame results from a linear-predictive-coding analysis using different window shapes according to the order of a particular spectral model within the frame.
References Cited (Backward Citations)
US4385393A
Cited
US4536886A
Cited
US4667340A
Cited
US5067158A
Cited
US4811398A
Cited
US4969192A
Cited
EP0308817A2
Cited
US4964166A
Cited
US5384891A
Cited
US4956871A
Cited
EP0424121A2
Cited
US5230036A
Cited
US5444816A
Cited
EP0500076A2
Cited
US5351338A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-09-01 | 2001-03-03 | 2001-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-09-01 | 2005-03-03 | 2005-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-09-01 | 2009-03-03 | 2009-09-02 | $7700.00 | Window Closed / Lapsed |