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US 4,045,616 AGranted
Vocoder system
AssigneeTime/Data Corporation
InventorEdwin A. Sloane
Life of this patent
Estimating the term…
Abstract
The Laplace transform (s-plane) is obtained for contiguous or overlapping frames of speech (or other signals) and polepair parameters (frequency, damping, magnitude and phase) are selected for transmission so as to preserve maximum energy. Speech is reconstructed from the transmitted parameters, using, for example, a damped sine wave as the equivalent of a pole pair. No separate pitch determination is made, nor is a voiced/unvoiced decision required.
Claims32
A vocoder system comprising:
- input means for receiving an input signal;
- time-domain to frequency-domain transformation means for determining s-plane pole locations and residues for said input signal coupled to said input means and for providing an output signal representative of such pole locations and residues;
- and
- synthesizing means for synthesizing a signal from said output signal representative of such pole locations and residues, coupled to said transformation means;
- whereby a signal representative of voice or the like may be stored or transmitted in the form of s-plane parameters.
2 more elements
A system for transmitting an input signal in a coded form comprising:
- Laplace transform means for computing the Laplace transform of said input signal and for providing an output signal representative of the pole-pairs of said input signal;
- and
- thresholding means, coupled to said Laplace transform means for selecting pole-pairs from said output signal of said Laplace transform means for transmission;
- whereby said input signal may be transmitted in the form of selected pole-pairs.
1 more element
An analyzer for vocoding an input signal comprising:
- input means for receiving said input signal and for ordering it into a plurality of frames;
- Laplace transform means for determining the frequency, damping rate, phase angle and amplitude of the s-plane poles for each of said frames, coupled to said input means;
- energy computation means for determining the energy associated with each pole coupled to said Laplace transform means;
- selection means for selecting poles from each frame so as to preserve maximum energy content, coupled to said energy computation means;
- whereby the characteristics of those poles associated with the highest energy are preserved for transmission or recording.
2 more elements
A method for coding an analog signal for transmission or recording comprising the steps of:
- converting said analog to a plurality of periodic frames of digital signals by an analog-to-digital converter;
- transforming each of said frames of digital signals to an s-plane representation by a Laplace transform means;
- determining the energy associated with the poles of said s-plane representation for each frame of said digital signal by comparator means;
- and
- selecting for transmission or recording those poles having the highest energy content for each frame of said digital signal by a comparator means.
2 more elements
A system for vocoding an input signal for transmission and synthesizing an output signal from the transmitted information comprising:
- input means for converting said input signal into a plurality of periodic frames of digital signals;
- pole-pair computer means for determining the pole-pair characteristics in the s-plane for said pole-pairs of each frame of said digital signal, said pole-pair computer means being coupled to said input means;
- energy detector means, coupled to said pole-pair computer means for selecting for transmission the pole-pair for each frame having the highest energy content;
- synthesizing means for receiving said characteristics of said transmitted pole-pair for each frame of said digital signal and for synthesizing an output signal representative of said input signal;
- whereby said input signal is transmitted in the form of a plurality of pole-pairs.
2 more elements
A vocoder system comprising:
- input means for receiving an input signal;
- time-domain to frequency-domain transformation means coupled to said input means for determining s-plane pole locations and residues for said input signal and for providing an output signal containing said pole locations and residues;
- selection means coupled to said transformation means for selecting pole locations from said output signal and for providing an output signal containing said selected pole locations and the residues associated therewith;
- and
- synthesizing means coupled to said selection means for synthesizing a signal from said output signal containing said selected pole locations and residues;
- whereby a signal representative of voice or the like may be stored or transmitted in the form of selected s-plane parameters.
3 more elements
A system for transmitting an input system in a coded form comprising:
- input means for receiving said input signal;
- time-domain to frequency-domain transformation means coupled to said input means for determining s-plane pole locations and residues for said input signal and for providing an output signal containing said pole locations and residues;
- and
- selection means coupled to said transformation means for selecting pole locations from said output signal for transmission;
- whereby said input signal may be transmitted in the form of selected s-plane parameters.
2 more elements
A method for coding a signal for transmission or recording comprising the steps of:
- ordering said signal into a plurality of frames;
- transforming each of said frames of signals to an s-plane representation by a Laplace transform means;
- and
- selecting for transmission or recording certain ones of the poles of said s-plane representation for each frame of said signal.
1 more element
Dependencies are inferred from the claim text.