US3878475A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for reproducing carrier wave for n differential phase shift keyed modulated wave
Assignee: Mitsubishi Electric Corp
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Filing: 1973-12-28
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Granted: 1975-04-15
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Expires: 1993-12-28
Abstract
Abstract A 4 differential phase shift keyed modulated signal is splitted into four signal portions having incremenal phase shifts of pi /2. The signal portions are phase detected with a reproduced carrier wave respectively. When each of the detected signal portions is under a predetermined threshold level as determined by an individual level discriminator that detected signal portion pi /2 lagging or leading phase with respect to the same is passed through the associated gate circuit to a composition circuit. The circuit composes the signal portions into a sawtoothed waveform. The waveform is supplied to a voltage controlled oscillator where the carrier wave is reproduced.
Inventors
- 👤 Akira Okano
- 👤 Yoichi Moritani
- 👤 Masahiro Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:55
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/18; H04L27/22; H04L27/227; H04L27/2271; H04L27/2272
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
156 words
A system for reproducing a carrier wave for an n differential phase shift keyed modulated signal, where n is an integer having a value of at least two(2), comprising, in combination, n phase detectors for phase detecting said n differential phase shift keyed, modulated signal, an (m + 1)th one of said phase detector detecting said n differential phase shift keyed, modulated signal with an axis of phase detection of 2 pi (m - 1) pi /n where m is an integer satisfying the relationship n > OR = m > OR = 1, and a control circuit for controlling the passage of an detected output from each of said phase detectors therethrough so that, when the detected output from the mth phase detector is under a predetermined threshold level, that phase detector having the axis of phase detection adjacent to that of the mth phase detector has its detected output passed through said control circuit.
Claim 2
Independent Claim
156 words
A system for reproducing a carrier wave for an n differential phase shift keyed modulated signal, where n is an integer having a value of at least two(2), comprising, in combination, n phase detectors for phase detecting said n differential phase shift keyed, modulated signal, an (m + 1)th one of said phase detector detecting said n differential phase shift keyed, modulated signal with an axis of phase detection of 2 pi (m - 1) pi /n where m is an integer satisfying the relationship n > OR = m > OR = 1, and a control circuit for controlling the passage of an detected output from each of said phase detectors therethrough so that, when the detected output from the mth phase detector is under a predetermined threshold level, that phase detector having the axis of phase detection adjacent to that of the mth phase detector has its detected output passed through said control circuit.
Claim 3
Dependent Claim
81 words
A system for reproducing a carrier wave as claimed in claim 1, further comprising a composition circuit for composing those portions of the detected outputs from said phase detectors passed through said control circuit, a voltage controlled oscillator electrically coupled to said composition circuit to oscillate in accordance with an output voltage from said composition circuit, and means for feeding an oscillating signal from said voltage controlled oscillator back to each of said phase detectors to form a phase locked loop.
Claim 4
Dependent Claim
84 words
A system for reproducing a carrier wave as claimed in claim 1, wherein said control circuit causes the detected output from the (m + 1)th phase detector, where m is not equal to n to pass therethrough as long as a detected output from the mth phase detector is under the predetermined threshold level and also the detected output from the first phase detector to pass therethrough as long as the detected output from the nth phase detector is under the predetermined threshold level.
Claim 5
Dependent Claim
124 words
A system for reproducing a carrier wave as claimed in claim 3, wherein said control circuit includes n gate circuits for controlling the passage of the detected outputs from said phase detectors respectively and n level discriminators for discriminating the levels of the detected outputs from said phase detectors respectively, so that that level discriminator discriminating the level of the detected output from the mth phase detector is operative to gate the gate circuit for controlling the passage of the detected output from the mth phase detectort, while that level discriminator discriminating the level of the detected output from the nth phase detector is operative to drive the gate circuit for controlling the passage of the detected output from the first phase detector therethrough.
Claim 6
Dependent Claim
84 words
A system for reproducing a carrier wave as claimed in claim 1, wherein said control circuit causes the detected output from the (m - 1) phase detector to pass therethrough, where m is not equal to one(1), as long as the detected output from the mth phase detector is under the predetermined threshold level and also the detected output from the nth phase detector to pass therethrough as long as the detected output from the first phase detector is under the predetermined threshold level.
Claim 7
Dependent Claim
124 words
A system for reproducing a carrier wave as claimed in claim 5, wherein said control circuit includes n gate circuits for controlling the passage of the detected output from said phase detectors respectively and n level discriminator for discriminating levels of the detected outputs from said phase detectors respectively so that that level discriminator discriminating the level of the detected output from the mth phase detector is operative to drive the gate circuit for controlling the passage of the detected output from the (m - 1)th phase detector while that level discriminator discriminating the level of the detected output from the first phase detector is operative to control the gate circuit for controlling the passage of the detected output from the nth phase detector.
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) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |