US5371853A
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US
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Method and system for CELP speech coding and codebook for use therewith
Assignee: University of Maryland, College Park
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Filing: 1991-10-28
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Granted: 1994-12-06
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Expires: 2011-10-28
Abstract
Abstract Apparatus and method for encoding speech using a codebook excited linear predictive (CELP) speech processor and an algebraic codebook for use therewith. The CELP speech processor receives a digital speech input representative of human speech and performs linear predictive code analysis and perceptual weighting filtering to produce a short term speech information and a long term speech information. The CELP speech processor utilizes an organized, non-overlapping, algebraic codebook containing a predetermined number of vectors, uniformly distributed over a multi-dimensional sphere to generate a remaining speech residual. The short term speech information, long term speech information and remaining speech residual are combinable to form a quality reproduction of the digital speech input.
Inventors
- 👤 Yuhung Kao
- 👤 John Baras
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:53
CPC Classifications
G; G10; G10L; G10L19/00; G10L19/04; G10L19/08; G10L19/12; G10L2019/0001; G10L2019/0004; G10L2019/0007; G10L2019/0008; G10L2019/0011
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
247 words
A codebook excited linear predictive (CELP) speech processor comprising: means for supplying a digital speech input representative of human speech; means for performing linear predictive code analysis and perceptual weight filtering on said digital speech input to obtain short term speech information; means for performing linear predictive code analysis and perceptual weight filtering on said digital speech input to obtain long term speech information; a deterministic non-overlapping codebook of a first predetermined number of vectors which are uniformly distributed over a multi-dimensional sphere, each of the first predetermined number of vectors being partitioned into a second predetermined number of sub-vectors, a substantial number of elements of each of the second predetermined number of sub-vectors being defined as zero, and a remaining even number of elements of each of the second predetermined number of sub-vectors defined as +1 or -1, wherein four elements with an index=5N (where N is an integer from 0 to 3) are non-zero for each of the second predetermined number of subvectors and the four non-zero elements of each of the second predetermined number of sub-vectors are all -1, all +1, or two are -1 and two are +1; and means for generating a remaining speech residual of the digital speech input from the deterministic codebook; the short term speech information, the long term speech information and the remaining speech residual being combinable to form a quality reproduction of the digital speech input to reproduce the human speech represented by said digital speech input.
Claim 2
Dependent Claim
247 words
A codebook excited linear predictive (CELP) speech processor comprising: means for supplying a digital speech input representative of human speech; means for performing linear predictive code analysis and perceptual weight filtering on said digital speech input to obtain short term speech information; means for performing linear predictive code analysis and perceptual weight filtering on said digital speech input to obtain long term speech information; a deterministic non-overlapping codebook of a first predetermined number of vectors which are uniformly distributed over a multi-dimensional sphere, each of the first predetermined number of vectors being partitioned into a second predetermined number of sub-vectors, a substantial number of elements of each of the second predetermined number of sub-vectors being defined as zero, and a remaining even number of elements of each of the second predetermined number of sub-vectors defined as +1 or -1, wherein four elements with an index=5N (where N is an integer from 0 to 3) are non-zero for each of the second predetermined number of subvectors and the four non-zero elements of each of the second predetermined number of sub-vectors are all -1, all +1, or two are -1 and two are +1; and means for generating a remaining speech residual of the digital speech input from the deterministic codebook; the short term speech information, the long term speech information and the remaining speech residual being combinable to form a quality reproduction of the digital speech input to reproduce the human speech represented by said digital speech input.
Claim 3
Dependent Claim
50 words
The codebook excited linear predictive (CELP) speech processor of claim 1, said means for generating a remaining speech residual including, means for calculating a plurality of inner products for a speech residual vector, representative of the remaining speech residual, with respect to each of the first predetermined number of vectors.
Claim 4
Dependent Claim
171 words
The codebook excited linear predictive (CELP) speech processor of claim 2, said means for calculating a plurality of inner products including, means for selecting the remaining even number of elements of each of the second predetermined number of subvectors defined as +1 or -1, means for calculating a plurality of sums for each of the second predetermined number of subvectors, based on the selected remaining even numbers of elements, for each of the first predetermined number of vectors, means for selecting all possible combinations of the plurality of sums for each of the second predetermined number of subvectors, means for summing all possible combinations of the plurality of sums for each of the second predetermined number of subvectors, to obtain the plurality of inner products, means for perceptual weighting each of the first predetermined number of vectors by convolving each of the first predetermined number of vectors with an impulse response, utilizing a FIR filter, and means for detecting an energy level for each of the first predetermined number of vectors.
Claim 5
Dependent Claim
39 words
The codebook excited linear predictive (CELP) speech processor of claim 1, wherein said CELP speech processor is used to transmit and receive a digital speech input, representative of human speech, at data rates from 2.4 Kbps to 16 Kbps.
Claim 6
Dependent Claim
37 words
The codebook excited linear predictive (CELP) speech processor of claim 4, wherein said CELP speech processor is used to transmit and receive a digital speech input, representative of human speech, at a data rate of 4.8 kbps.
Claim 7
Dependent Claim
17 words
The codebook excited linear predictive (CELP) speech processor of claim 1, wherein the multi-dimensional sphere is 60-dimensional.
Claim 8
Dependent Claim
28 words
The codebook excited linear predictive (CELP) speech processor of claim 1, wherein the first predetermined number of vectors, uniformly distributed over the 60-dimensional sphere is equal to 512.
Claim 9
Dependent Claim
29 words
The codebook excited linear predictive (CELP) speech processor of claim 7, wherein the second predetermined number of subvectors is equal to 1,536, and wherein each subvector contains 20 elements.
Claim 10
Dependent Claim
28 words
The codebook excited linear predictive (CELP) speech processor of claim 8, wherein a value of each of the elements of the 1,536 subvectors is -1, 0, or 1.
Claim 11
Dependent Claim
26 words
The codebook excited linear predictive (CELP) speech processor of claim 9, wherein 80% of the elements of each of the 1,536 subvectors is equal to zero.
Claim 12
Dependent Claim
25 words
The codebook excited linear predictive (CELP) speech processor of claim 10, wherein an even number of elements of each of the 1,536 subvectors are non-zero.
Claim 13
Independent Claim
208 words
A method of encoding speech data including the steps of providing a digital speech input, performing linear predictive code analysis and perceptual weight filtering on the digital speech input to produce a short and long term speech information and generating a deterministic non-overlapping codebook of a first predetermined number of vectors which are uniformly distributed over a multi-dimensional sphere comprising the steps of: a) partitioning each of the first predetermined number of vectors into a second predetermined number of sub-vectors; b) setting a substantial number of elements of each of the second predetermined number of sub-vectors to zero; c) setting a remaining even number of elements of each of the second number of sub-vectors to 1 or -1, wherein four elements with an index of SN (where N is an integer from 0 to 3) are non-zero for each of the second number of sub-vectors and the four non-zero elements of each sub-vector are all -1, all +1, or two are -1 and two are +1; and d) generating a remaining speech residual of the digital speech input from the deterministic codebook such that the short and long term speech information and the remaining speech residual are combinable to form a quality reproduction of the digital speech input.
Claim 14
Independent Claim
208 words
A method of encoding speech data including the steps of providing a digital speech input, performing linear predictive code analysis and perceptual weight filtering on the digital speech input to produce a short and long term speech information and generating a deterministic non-overlapping codebook of a first predetermined number of vectors which are uniformly distributed over a multi-dimensional sphere comprising the steps of: a) partitioning each of the first predetermined number of vectors into a second predetermined number of sub-vectors; b) setting a substantial number of elements of each of the second predetermined number of sub-vectors to zero; c) setting a remaining even number of elements of each of the second number of sub-vectors to 1 or -1, wherein four elements with an index of SN (where N is an integer from 0 to 3) are non-zero for each of the second number of sub-vectors and the four non-zero elements of each sub-vector are all -1, all +1, or two are -1 and two are +1; and d) generating a remaining speech residual of the digital speech input from the deterministic codebook such that the short and long term speech information and the remaining speech residual are combinable to form a quality reproduction of the digital speech input.
Claim 15
Dependent Claim
41 words
The method of encoding speech data of claim 12, said generating step including, calculating a plurality of inner products for a speech residual vector, representative of the remaining speech residual, with respect to each of the first predetermined number of vectors.
Claim 16
Dependent Claim
151 words
The method of encoding speech data of claim 13, said calculating step including, selecting the remaining even number of elements of each of the second predetermined number of subvectors defined as +1 or -1, calculating a plurality of sums for each of the second predetermined number of subvectors, based on the selected remaining even number of elements, for each of the first predetermined number of vectors, selecting all possible combinations of the plurality of sums for each of the second predetermined number of subvectors, summing all possible combinations of the plurality of sums for each of the second predetermined number of subvectors, to obtain the plurality of inner products, perceptual weighing each of the first predetermined number of vectors by convolving each of the first predetermined number of vectors with an impulse response, utilizing a FIR filter, and detecting an energy level for each of the first predetermined number of vectors.
Claim 17
Dependent Claim
30 words
The method of claim 12, wherein a data rate of the digital speech input and the quality reproduction of the digital speech input is from 2.4 kbps to 16 kpbs.
Claim 18
Dependent Claim
26 words
The method of claim 15, wherein a data rate of the digital speech input and the quality reproduction of the digital speech input is 4.8 kbps.
Claim 19
Dependent Claim
11 words
The method of claim 12, wherein the multi-dimensional sphere is 60-dimensional.
Claim 20
Dependent Claim
22 words
The method of claim 12, wherein the first predetermined number of vectors, uniformly distributed over the 60-dimensional sphere is equal to 512.
Claim 21
Dependent Claim
23 words
The method of claim 18, wherein the second predetermined number of subvectors is equal to 1,536, and wherein each subvector contains 20 elements.
Claim 22
Dependent Claim
22 words
The method of claim 19, wherein the value of each of the elements of the 1,536 subvectors is -1, 0, or 1.
Claim 23
Dependent Claim
20 words
The method of claim 20, wherein 80% of the elements of each of the 1,536 subvectors is equal to zero.
Claim 24
Dependent Claim
16 words
The method of claim 21, wherein an even number of elements of each subvector are non-zero.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-12-05 | 1998-06-06 | 1998-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-05 | 2002-06-06 | 2002-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-05 | 2006-06-06 | 2006-12-06 | $7700.00 | Window Closed / Lapsed |