US4433434A
Expired / Lapsed
US
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Method and apparatus for time domain compression and synthesis of audible signals
Assignee: ESS Technology Inc
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Filing: 1981-12-28
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Granted: 1984-02-21
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Expires: 2001-12-28
Abstract
Abstract Compression and synthesis techniques and related apparatus for time domain signals, particularly signals whose information content resides in the power spectrum such as speech. Compression techniques include adjusting the phase of harmonic components of a signal unit to obtain an equivalent power spectrum signal of a minimum number of discrete levels. The invention finds application in speech compression and compact speech synthesis devices.
Inventors
- 👤 Forrest S. Mozer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:45
CPC Classifications
G; G10; G10L; G10L13/00; G10L13/08; G10L19/00; G10L19/02
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
91 words
A method for compressing a time domain information signal, said method comprising the steps of: receiving said information signal; and adjusting the phase of harmonic components of said received signal to produce an equivalent signal, said equivalent signal having sampled amplitude values at selected sample times, said amplitude values being limited to a selected maximum number of amplitude levels less than the number of amplitude levels utilized to define said information signal at said selected sample times, said equivalent signal having a power spectrum substantially the same as said information signal.
Claim 2
Independent Claim
91 words
A method for compressing a time domain information signal, said method comprising the steps of: receiving said information signal; and adjusting the phase of harmonic components of said received signal to produce an equivalent signal, said equivalent signal having sampled amplitude values at selected sample times, said amplitude values being limited to a selected maximum number of amplitude levels less than the number of amplitude levels utilized to define said information signal at said selected sample times, said equivalent signal having a power spectrum substantially the same as said information signal.
Claim 3
Dependent Claim
22 words
The method according to claim 1 wherein the number of permissible peak non-zero amplitude values is no more than two magnitude levels.
Claim 4
Dependent Claim
24 words
The method according to claim 1 or 2 wherein the permissible peak non-zero amplitude values are symmetric with respect to a zero reference level.
Claim 5
Independent Claim
101 words
An apparatus for compressing a time domain information signal comprising: means operative to receive said information signal; and means coupled to said receiving means for adjusting the phase of harmonic components of said received information signal to produce an equivalent signal having a power spectrum substantially the same as said information signal, said adjusting means further producing said equivalent signal as a serial sequence of sampled amplitude values at selected sample times which is limited to a selected maximum number of amplitude levels less than the number of amplitude levels utilized to define said information signal at said selected sample times.
Claim 6
Independent Claim
101 words
An apparatus for compressing a time domain information signal comprising: means operative to receive said information signal; and means coupled to said receiving means for adjusting the phase of harmonic components of said received information signal to produce an equivalent signal having a power spectrum substantially the same as said information signal, said adjusting means further producing said equivalent signal as a serial sequence of sampled amplitude values at selected sample times which is limited to a selected maximum number of amplitude levels less than the number of amplitude levels utilized to define said information signal at said selected sample times.
Claim 7
Dependent Claim
28 words
The apparatus according to claim 4 further including means limiting the number of permissible non-zero amplitudes values at selected sample times to no more than two magnitude levels.
Claim 8
Dependent Claim
32 words
The apparatus according to claim 4 or 5 further including means limiting permissible non-zero amplitude values at selected sample times to values which are symmetric with respect to a zero reference level.
Claim 9
Independent Claim
105 words
A method for compressing a time domain information signal whose information content resides mainly in its power spectrum comprising the steps of: digitizing a finite segment of said time domain signal; analyzing said digitized waveform to determine amplitude and phase parameters in terms of harmonically related transcendental functions; and altering the magnitude and sign of selected ones of said phase parameters without modifying said amplitude parameters to obtain an equivalent time domain signal whose amplitude in the time domain may be reconstructed by a selected limited maximum number of finite amplitude values less than the number of amplitude values required to digitize said information signal.
Claim 10
Independent Claim
105 words
A method for compressing a time domain information signal whose information content resides mainly in its power spectrum comprising the steps of: digitizing a finite segment of said time domain signal; analyzing said digitized waveform to determine amplitude and phase parameters in terms of harmonically related transcendental functions; and altering the magnitude and sign of selected ones of said phase parameters without modifying said amplitude parameters to obtain an equivalent time domain signal whose amplitude in the time domain may be reconstructed by a selected limited maximum number of finite amplitude values less than the number of amplitude values required to digitize said information signal.
Claim 11
Dependent Claim
32 words
The method according to claim 7 wherein said altering step comprises Fourier transforming said time domain information signal into the frequency domain to determine frequency and phase components of said information signal.
Claim 12
Independent Claim
114 words
An apparatus for synthesizing from compressed information an output signal which is substantially equivalent to a source time domain signal whose information content resides mainly in its power spectrum, said apparatus comprising: memory means for storing digital representations of the amplitude of segments of a compressed time domain signal and for storing instructions correlating said segments to said output signal; and means responsive to said digital representations and said instruction signals for constructing said output signal from said segments, said segments having a limited maximum number of finite amplitude values at selected sample times and said output signal having a power spectrum substantially equivalent to but having phase components differing from said source signal.
Claim 13
Independent Claim
114 words
An apparatus for synthesizing from compressed information an output signal which is substantially equivalent to a source time domain signal whose information content resides mainly in its power spectrum, said apparatus comprising: memory means for storing digital representations of the amplitude of segments of a compressed time domain signal and for storing instructions correlating said segments to said output signal; and means responsive to said digital representations and said instruction signals for constructing said output signal from said segments, said segments having a limited maximum number of finite amplitude values at selected sample times and said output signal having a power spectrum substantially equivalent to but having phase components differing from said source signal.
Claim 14
Dependent Claim
28 words
The apparatus according to claim 9 further including means for limiting the number of non-zero amplitude values at selected sample times to no more than two magnitude levels.
Claim 15
Dependent Claim
26 words
The apparatus according to claim 9 or 10 further including means limiting permissible non-zero amplitude values which are symmetric with respect to a zero reference level.
Claim 16
Independent Claim
107 words
A method for synthesizing from compressed information an output signal which is substantially equivalent to a source time domain signal whose information content resides mainly in its power spectrum, said method comprising: storing digital representations of the amplitude of segments of a compressed time domain signal with representations of instruction signals correlating said segments to said output signal; and constructing said output signal from said segments in response to said instruction signals, said segments having a limited maximum number of finite amplitude values at selected sample times and said output signal having a power spectrum substantially equivalent to but having phase components differing from said source signal.
Claim 17
Independent Claim
107 words
A method for synthesizing from compressed information an output signal which is substantially equivalent to a source time domain signal whose information content resides mainly in its power spectrum, said method comprising: storing digital representations of the amplitude of segments of a compressed time domain signal with representations of instruction signals correlating said segments to said output signal; and constructing said output signal from said segments in response to said instruction signals, said segments having a limited maximum number of finite amplitude values at selected sample times and said output signal having a power spectrum substantially equivalent to but having phase components differing from said source signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-20 | 1987-08-22 | 1988-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-20 | 1991-08-22 | 1992-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-20 | 1995-08-22 | 1996-02-21 | $7700.00 | Window Closed / Lapsed |