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US3815034A
Expired / Lapsed
US
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Demodulator for phase-modulated carrier waves
Assignee: NEC Corp
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Filing: 1972-09-28
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Granted: 1974-06-04
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Expires: 1992-09-28
Abstract
Abstract A demodulator for a multi-phase phase-modulated signal carrier wave having 2m-phase phase-modulated bursts, m being a positive integer, and where each burst has at its leading end portion a 2n-phase phase-modulated synchronizing signal, n being a positive integer smaller than m. The synchronizing signal of each burst is temporarily phase-demodulated by a 2n-phase phase demodulator until the phase difference between the signal carrier wave and a reference carrier wave derived from the signal carrier wave is eliminated to permit demodulation of the remainder of the 2mphase phase-modulated burst.
Inventors
- 👤 K Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:42
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/18; H04L27/22; H04L27/227; H04L27/2271; H04L27/2273; H04L7/00; H04L7/04; H04L7/041; H04L7/046
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
244 words
A demodulator for a multi-phase phase-modulated signal carrier wave for use in a time-division multiplex communication system, said carrier wave having 2m-phase phase-modulated bursts where m is a positive integer, each of said bursts having at its leading end portion a 2n-phase period where said carrier wave is 2n-phase phase-modulated and n is a positive integer smaller than m, comprising: first means responsive to the incoming carrier wave component for generating a reference carrier wave synchronized with said signal carrier wave; second means responsive to the incoming carrier wave component and to the output of said first means for detecting said 2n-phase phasemodulated portions to produce an output indicative of the duration of each of the last-mentioned portions; third means for subjecting said reference carrier wave to phase shifting for generating a first group of m-kinds of phase-shifted reference carrier waves and a second group of n-kinds of reference carrier waves respectively for the demodulation of the 2m-phase and 2nphase phase-modulated portions of said signal carrier wave; switching means responsive to the output of said second means for selectively allowing only said n phase-shifted carrier waves to pass therethrough as an output during said 2n-phase period and for allowing only said m phase-shifted carrier waves to pass therethrough as an output during the period other than said 2nphase period; and m phase detector means supplied with said signal carrier wave and with the outputs of said switching means and providing a 2m-phase phase-demodulated output.
Claim 2
Dependent Claim
244 words
A demodulator for a multi-phase phase-modulated signal carrier wave for use in a time-division multiplex communication system, said carrier wave having 2m-phase phase-modulated bursts where m is a positive integer, each of said bursts having at its leading end portion a 2n-phase period where said carrier wave is 2n-phase phase-modulated and n is a positive integer smaller than m, comprising: first means responsive to the incoming carrier wave component for generating a reference carrier wave synchronized with said signal carrier wave; second means responsive to the incoming carrier wave component and to the output of said first means for detecting said 2n-phase phasemodulated portions to produce an output indicative of the duration of each of the last-mentioned portions; third means for subjecting said reference carrier wave to phase shifting for generating a first group of m-kinds of phase-shifted reference carrier waves and a second group of n-kinds of reference carrier waves respectively for the demodulation of the 2m-phase and 2nphase phase-modulated portions of said signal carrier wave; switching means responsive to the output of said second means for selectively allowing only said n phase-shifted carrier waves to pass therethrough as an output during said 2n-phase period and for allowing only said m phase-shifted carrier waves to pass therethrough as an output during the period other than said 2nphase period; and m phase detector means supplied with said signal carrier wave and with the outputs of said switching means and providing a 2m-phase phase-demodulated output.
Claim 3
Dependent Claim
35 words
A demodulator as defined in claim 1 wherein said switching means comprises m switching circuits, and wherein said phase detector means comprises m 2n-phase phase detectors supplied respectively with the outputs of said switching circuits.
Claim 4
Dependent Claim
83 words
A demodulator as defined in claim 2 where m 2 and n 1, and wherein said third means generates first, second and third phase-shifted reference carrier waves, the phase difference between said second wave and each of said first and second waves being 45 degrees but in opposite directions, one of said switching circuits being supplied with said first and second phase-shifted reference carrier waves, and the other of said switching circuits being supplied with said second and third phase-shifted reference carrier waves.
Claim 5
Independent Claim
171 words
A method of demodulating a multi-phase phase modulated signal carrier wave having periodic 2m-phase phase modulated portions where m is a positive integer, each of said portions having at its leading end portion a 2n-phase period where said carrier wave is 2n-phase phase modulated and n is a positive integer smaller than m, said method comprising: generating a reference carrier wave synchronized with said signal carrier wave; detecting said 2n-phase phase modulated portions to produce an output indicative of the duration of each of the last-mentioned portions; phase shifting said reference carrier wave to generate a group of m and n kinds of phase-shifted reference carrier waves respectively for the demodulation of the 2m-phase and 2n-phase phase modulated portions of said signal carrier wave; and selectively combining, in response to said output, said signal carrier wave with a group of n kinds of phase-shifted carrier waves only during said 2n-phase period and with a group of m kinds of phase-shifted carrier waves only during the period other than said 2n-phase period.
Claim 6
Independent Claim
171 words
A method of demodulating a multi-phase phase modulated signal carrier wave having periodic 2m-phase phase modulated portions where m is a positive integer, each of said portions having at its leading end portion a 2n-phase period where said carrier wave is 2n-phase phase modulated and n is a positive integer smaller than m, said method comprising: generating a reference carrier wave synchronized with said signal carrier wave; detecting said 2n-phase phase modulated portions to produce an output indicative of the duration of each of the last-mentioned portions; phase shifting said reference carrier wave to generate a group of m and n kinds of phase-shifted reference carrier waves respectively for the demodulation of the 2m-phase and 2n-phase phase modulated portions of said signal carrier wave; and selectively combining, in response to said output, said signal carrier wave with a group of n kinds of phase-shifted carrier waves only during said 2n-phase period and with a group of m kinds of phase-shifted carrier waves only during the period other than said 2n-phase period.
References Cited (Backward Citations)
US3294907A
Cited
US3417333A
Cited
US3588349A
Cited
US3697881A
Cited
US3594651A
Cited
US3675139A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |