Patent US5754974A successfully refreshed from Google Patents.
US5754974A
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Spectral magnitude representation for multi-band excitation speech coders
Assignee: Digital Voice Systems Inc
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Filing: 1995-02-22
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Granted: 1998-05-19
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Expires: 2015-02-22
Abstract
Abstract A method for encoding a speech signal into digital bits including the steps of dividing the speech signal into speech frames representing time intervals of the speech signal, determining voicing information for frequency bands of the speech frames, and determining spectral magnitudes representative of the magnitudes of the spectrum at determined frequencies across the frequency bands. The method further includes quantizing and encoding the spectral magnitudes and the voicing information. The steps of determining, quantizing and encoding the spectral magnitudes is done is such a manner that the spectral magnitudes independent of voicing information are available for later synthesizing.
Inventors
- 👤 Daniel W. Griffin
- 👤 John C. Hardwick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:19
CPC Classifications
G; G10; G10L; G10L25/00; G10L25/93; G10L19/00; G10L19/04; G10L19/08; G10L19/10
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
155 words
A method for encoding a speech signal into a plurality of digital bits from which the speech signal can later be synthesized, the method comprising the steps of: processing the speech signal to divide the signal into a plurality of speech frames, each of the speech frames representing a time interval of the speech signal; processing the speech frames to determine voicing information for a plurality of frequency bands of the speech frames; processing the speech frames to determine spectral magnitudes representative of the magnitudes of the spectrum at determined frequencies across the frequency bands, and quantizing and encoding the spectral magnitudes and the voicing information for subsequent use in decoding and synthesizing the speech signal, wherein the processing of the speech frames to determine spectral magnitudes and the quantizing and encoding of the spectral magnitudes is done in such a manner that spectral magnitudes independent of the voicing information are available for later synthesizing.
Claim 2
Independent Claim
155 words
A method for encoding a speech signal into a plurality of digital bits from which the speech signal can later be synthesized, the method comprising the steps of: processing the speech signal to divide the signal into a plurality of speech frames, each of the speech frames representing a time interval of the speech signal; processing the speech frames to determine voicing information for a plurality of frequency bands of the speech frames; processing the speech frames to determine spectral magnitudes representative of the magnitudes of the spectrum at determined frequencies across the frequency bands, and quantizing and encoding the spectral magnitudes and the voicing information for subsequent use in decoding and synthesizing the speech signal, wherein the processing of the speech frames to determine spectral magnitudes and the quantizing and encoding of the spectral magnitudes is done in such a manner that spectral magnitudes independent of the voicing information are available for later synthesizing.
Claim 3
Dependent Claim
159 words
Apparatus for encoding a speech signal into a plurality of digital bits from which the speech signal can later be synthesized, the apparatus comprising: means for processing the speech signal to divide the signal into a plurality of speech frames, each of the speech frames representing a time interval of the speech signal; means for processing the speech frames to determine voicing information for a plurality of frequency bands of the speech frames; means for processing the speech frames to determine spectral magnitudes representative of the magnitudes of the spectrum at determined frequencies across the frequency bands, and means for quantizing and encoding the spectral magnitudes and the voicing information for subsequent use in decoding and synthesizing the speech signal, wherein the processing of the speech frames to determine spectral magnitudes and the quantizing and encoding of the spectral magnitudes is done in such a manner that spectral magnitudes independent of the voicing information are available for later synthesizing.
Claim 4
Dependent Claim
159 words
Apparatus for encoding a speech signal into a plurality of digital bits from which the speech signal can later be synthesized, the apparatus comprising: means for processing the speech signal to divide the signal into a plurality of speech frames, each of the speech frames representing a time interval of the speech signal; means for processing the speech frames to determine voicing information for a plurality of frequency bands of the speech frames; means for processing the speech frames to determine spectral magnitudes representative of the magnitudes of the spectrum at determined frequencies across the frequency bands, and means for quantizing and encoding the spectral magnitudes and the voicing information for subsequent use in decoding and synthesizing the speech signal, wherein the processing of the speech frames to determine spectral magnitudes and the quantizing and encoding of the spectral magnitudes is done in such a manner that spectral magnitudes independent of the voicing information are available for later synthesizing.
Claim 5
Dependent Claim
34 words
The subject matter of claim 1 or 2, wherein the speech signal is processed to estimate a parameter representative of the fundamental frequency, and the determined frequencies are harmonic multiples of the fundamental frequency.
Claim 6
Dependent Claim
40 words
The subject matter of claim 3, wherein the parameter representative of the fundamental frequency is quantized and encoded for each of the speech frames, so that the digital bits include information representing the spectral magnitudes, voicing information, and fundamental frequency.
Claim 7
Dependent Claim
18 words
The subject matter of claim 4, wherein the digital bits include redundant bits providing forward error correction coding.
Claim 8
Dependent Claim
18 words
The subject matter of claim 5 wherein the forward error correction coding includes Golay codes and Hamming codes.
Claim 9
Dependent Claim
28 words
The subject matter of claim 3, wherein the processing of the speech frames to determine the spectral magnitudes is done independently of the voicing information for the frame.
Claim 10
Dependent Claim
58 words
The subject matter of claim 7, wherein the voicing information represents whether particular frequency bands within a speech frame are processed as voiced or unvoiced bands, and the processing to determine spectral magnitudes determines the spectral magnitude for a particular determined frequency independently of whether the determined frequency is in a frequency band that is voiced or unvoiced.
Claim 11
Dependent Claim
42 words
The subject matter of claim 3, wherein the processing to determine spectral magnitudes includes a spectral transformation of the speech frames from time domain samples to frequency samples, and wherein the spectral magnitudes are formed as weighted sums of the frequency samples.
Claim 12
Dependent Claim
28 words
The subject matter of claim 9, wherein weights used in producing the weighted sums have the effect of compensating for the sampling grid used in the spectral transformation.
Claim 13
Dependent Claim
30 words
The subject matter of claim 1 or 2, wherein the processing of the speech frames to determine the spectral magnitudes is done independently of the voicing information for the frame.
Claim 14
Dependent Claim
58 words
The subject matter of claim 11, wherein the voicing information represents whether particular frequency bands within a speech frame are processed as voiced or unvoiced bands, and the processing to determine spectral magnitudes determines the spectral magnitude for a particular determined frequency independently of whether the determined frequency is in a frequency band that is voiced or unvoiced.
Claim 15
Dependent Claim
44 words
The subject matter of claim 1 or 2, wherein the processing to determine spectral magnitudes includes a spectral transformation of the speech frames from time domain samples to frequency samples, and wherein the spectral magnitudes are formed as weighted sums of the frequency samples.
Claim 16
Dependent Claim
28 words
The subject matter of claim 13 wherein weights used in producing the weighted sums have the effect of compensating for the sampling grid used in the spectral transformation.
Claim 17
Independent Claim
152 words
A method for encoding a speech signal into a plurality of digital bits from which the speech signal can later be synthesized, the method comprising the steps of: processing the speech signal to divide the signal into a plurality of speech frames, each of the speech frames representing a time interval of the speech signal; processing the speech frames to determine voicing information for a plurality of frequency bands of the speech frames; processing the speech frames to determine spectral magnitudes representative of the magnitudes of the spectrum at determined frequencies across the frequency bands, and quantizing and encoding the spectral magnitudes and the voicing information for subsequent use in decoding and synthesizing the speech signal, wherein the processing to determine spectral magnitudes includes a spectral transformation of the speech frames from time domain samples to frequency samples, and wherein the spectral magnitudes are formed as weighted sums of the frequency samples.
Claim 18
Independent Claim
152 words
A method for encoding a speech signal into a plurality of digital bits from which the speech signal can later be synthesized, the method comprising the steps of: processing the speech signal to divide the signal into a plurality of speech frames, each of the speech frames representing a time interval of the speech signal; processing the speech frames to determine voicing information for a plurality of frequency bands of the speech frames; processing the speech frames to determine spectral magnitudes representative of the magnitudes of the spectrum at determined frequencies across the frequency bands, and quantizing and encoding the spectral magnitudes and the voicing information for subsequent use in decoding and synthesizing the speech signal, wherein the processing to determine spectral magnitudes includes a spectral transformation of the speech frames from time domain samples to frequency samples, and wherein the spectral magnitudes are formed as weighted sums of the frequency samples.
Claim 19
Dependent Claim
156 words
Apparatus for encoding a speech signal into a plurality of digital bits from which the speech signal can later be synthesized, the apparatus comprising: means for processing the speech signal to divide the signal into a plurality of speech frames, each of the speech frames representing a time interval of the speech signal, means for processing the speech frames to determine voicing information for a plurality of frequency bands of the speech frames; means for processing the speech frames to determine spectral magnitudes representative of the magnitudes of the spectrum at determined frequencies across the frequency bands, and means for quantizing and encoding the spectral magnitudes and the voicing information for subsequent use in decoding and synthesizing the speech signal, wherein the processing to determine spectral magnitudes includes a spectral transformation of the speech frames from time domain samples to frequency samples, and wherein the spectral magnitudes are formed as weighted sums of the frequency samples.
Claim 20
Dependent Claim
156 words
Apparatus for encoding a speech signal into a plurality of digital bits from which the speech signal can later be synthesized, the apparatus comprising: means for processing the speech signal to divide the signal into a plurality of speech frames, each of the speech frames representing a time interval of the speech signal, means for processing the speech frames to determine voicing information for a plurality of frequency bands of the speech frames; means for processing the speech frames to determine spectral magnitudes representative of the magnitudes of the spectrum at determined frequencies across the frequency bands, and means for quantizing and encoding the spectral magnitudes and the voicing information for subsequent use in decoding and synthesizing the speech signal, wherein the processing to determine spectral magnitudes includes a spectral transformation of the speech frames from time domain samples to frequency samples, and wherein the spectral magnitudes are formed as weighted sums of the frequency samples.
Claim 21
Dependent Claim
30 words
The subject matter of claim 15 or 16, wherein weights used in producing the weighted sums have the effect of compensating for the sampling grid used in the spectral transformation.
Claim 22
Dependent Claim
34 words
The subject matter of claim 15 or 16, wherein the speech signal is processed to estimate a parameter representative of the fundamental frequency, and the determined frequencies are harmonic multiples of the fundamental frequency.
Claim 23
Dependent Claim
40 words
The subject matter of claim 18, wherein the parameter representative of the fundamental frequency is quantized and encoded for each of the speech frames, so that the digital bits include information representing the spectral magnitudes, voicing information, and fundamental frequency.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-18 | 2001-11-17 | 2002-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-18 | 2005-11-17 | 2006-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-18 | 2009-11-17 | 2010-05-19 | $7700.00 | Window Closed / Lapsed |