US3667047A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improved speech articulation frequency modulation communication system
Assignee: Toshiba Corp
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Filing: 1969-10-07
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Granted: 1972-05-30
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Expires: 1989-10-07
Abstract
Abstract The present invention provides a frequency modulation communication system wherein there is disposed in the transmitting side a first filter capable of furnishing transmission signals with such frequency characteristics of the voiced and unvoiced speech signal components as to allow information to be transmitted at the maximum rate possible with said transmission signals as well as with the transmission channel used and in the receiving side a second filter capable of bringing the frequency characteristics of signals received and frequency demodulated there back to the original state when said received signals were initially transmitted, thereby enabling the articulation of transmission signals to be improved with the said transmission channel, or enabling the same articulation of transmission signals to be maintained with a compressed frequency band width of the transmission channel and the prescribed frequency bandwidth to be compressed without any inconvenience.
Inventors
- 👤 Masahiro Iwasaki
- 👤 Nobuyuki Goto
- 👤 Hiroya Fujisaki
- 👤 Kunihiko Niwa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:15
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/189; H03F3/19; H03F3/191; H03F1/00; H03F1/02; H03F1/0205; H03F1/0211; H03F1/0244; H04; H04B; H04B1/00; H04B1/68; H03F2200/00; H03F2200/15; H03F2200/72
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
156 words
A frequency modulation communication system for improving the articulation of speech signals which include voiced and unvoiced signal components, said system comprising: a frequency modulation transmission means including a first filter for modifying the frequency characteristics of the voiced and unvoiced components of said speech signals prior to frequency modulation of said speech signals, the frequency characteristics P(f) of said first filter being: where: Phi 1(f): statistical average power spectral density of said voiced component, Phi 2(f):statistical average power spectral density of said unvoiced component, S1 :statistical average power of voiced component; and a frequency modulation receiving means for receiving signals transmitted from said transmission means and including a frequency demodulator and a second filter coupled to the output of said demodulator for bringing the frequency characteristics of the voiced and unvoiced components of said received speech signals back to the original state of said speech signals, the frequency characteristics of said second filters being: 1/P(f).
Claim 2
Dependent Claim
156 words
A frequency modulation communication system for improving the articulation of speech signals which include voiced and unvoiced signal components, said system comprising: a frequency modulation transmission means including a first filter for modifying the frequency characteristics of the voiced and unvoiced components of said speech signals prior to frequency modulation of said speech signals, the frequency characteristics P(f) of said first filter being: where: Phi 1(f): statistical average power spectral density of said voiced component, Phi 2(f):statistical average power spectral density of said unvoiced component, S1 :statistical average power of voiced component; and a frequency modulation receiving means for receiving signals transmitted from said transmission means and including a frequency demodulator and a second filter coupled to the output of said demodulator for bringing the frequency characteristics of the voiced and unvoiced components of said received speech signals back to the original state of said speech signals, the frequency characteristics of said second filters being: 1/P(f).
Claim 3
Dependent Claim
134 words
A frequency modulation communication system according to claim 1 wherein the first filter comprises a first resistor and first condenser connected in series between one of paired input terminals and one of paired output terminals, the input terminals of the first filter being coupled to the input of said transmitter and a second resistor, first coil and second condenser connected in series between said paired output terminals; and the second filter comprises a third resistor and second coil connected in series between one of paired input terminals and one of paired output terminals associated with said second filter, the output terminals of the second filter being coupled to the output of said receiver, and a fourth resistor, third coil and third condenser connected in series between said paired output terminals of said second filter.
Claim 4
Dependent Claim
36 words
A frequency modulation communication system accordding to claim 1 comprising an instantaneous compression circuit coupled to the output side of the first filter and an instantaneous expander coupled to the input side of the second filter.
Claim 5
Dependent Claim
36 words
A frequency modulation communication system according to claim 1 comprising an instantaneous compression circuit coupled to the input side of the first filter and an instantaneous expander coupled to the outPut side of the second filter.
Claim 6
Dependent Claim
35 words
A frequency modulation communication system according to claim 1 comprising a syllabic compressor coupled to the output side of the first filter and a syllabic expander coupled to the input side of the second filter.
Claim 7
Dependent Claim
35 words
A frequency modulation communication system according to claim 1 comprising a syllabic compressor coupled to the input side of the first filter and a syllabic expander coupled to the output side of the second filter.
Claim 8
Dependent Claim
39 words
A frequency modulation communication system according to claim 1 comprising a first frequency spectrum inverter connected to the output side of the first filter and a second frequency spectrum inverter connected to the input side of the second filter.
Claim 9
Dependent Claim
73 words
A frequency modulation communication system according to claim 2 comprising a first frequency spectrum rearrangement circuit coupled to the output of the first filter for separating a transmission signal into a plurality of frequency bands for interchange of frequency spectra; and a second frequency spectrum rearrangement circuit coupled to the input of the second filter for bringing the frequency spectrum of an input signal thereto back to that of the original transmission signal.
Claim 10
Dependent Claim
198 words
A frequency modulation transmission system according to claim 8 wherein the first and second frequency spectrum rearrangement circuits respectively comprise an input terminal supplied with an input signal having a frequency band f1 to f2, a first amplitude modulator connected to said input terminal, a first oscillator for supplying said first amplitude modulator with signals having a frequency f2 + f1 so that the frequency component f1 to f0 is amplitude modulated by said first amplitude modulator, a first band pass filter for taking a lower band component f1 to f2 out of outputs from said amplitude modulator, a second amplitude modulator connected to said first band pass filter, a second oscillator for supplying said second amplitude modulator with signals having a frequency 2f2 - (f0 - f1), a low pass filter for taking a lower band component f2 - (f0 - f1) to f2 out of outputs from said second amplitude modulator, a second band pass filter for taking signals having a frequency component f1 to f2 - (f0 -f1) out of outputs from the first amplitude modulator and a circuit for summing outputs from said low pass filter and those from said second band pass filter.
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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) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |