Patent US3597552A successfully refreshed from Google Patents.
US3597552A
Expired / Lapsed
US
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System synchronization system for a time division communication system employing digital control
Assignee: NEC Corp
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Filing: 1969-10-24
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Granted: 1971-08-03
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Expires: 1989-10-24
Abstract
Abstract A synchronization system for use in a time-division communication system makes almost exclusive use of digital circuits. Those circuits include means for detecting the phase differences between incoming clock signals from other stations and a reference clock signal of a particular station, and means for controlling the insertion or deletion of pulses into or from a reference clock pulse train in response to the sensed phase differences.
Inventors
- 👤 Hirokazu Goto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:20
CPC Classifications
H; H04; H04J; H04J3/00; H04J3/02; H04J3/06; H04J3/0635; H04J3/0676; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/085; H03L7/087
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
148 words
A synchronization system for a plurality of stations in a time division communication system for generating a pulse train to be used as the clock pulse for each of said stations, said system comprising means for detecting the phase differences between the incoming clock signals sent from other stations and the clock signal of its own; means operatively connected to said detecting means for measuring said phase differences in a digital fashion; means operatively connected to said measuring means for computing the differences between said phase differences and a preset reference phase difference; means operatively connected to said computing means for weighting and averaging the outputs of said computing means, and means operatively connected to said weighting and averaging means for controlling the insertion or deletion of pulse groups into or from a reference clock pulse train in response to the output of said weighting and averaging means.
Claim 2
Dependent Claim
148 words
A synchronization system for a plurality of stations in a time division communication system for generating a pulse train to be used as the clock pulse for each of said stations, said system comprising means for detecting the phase differences between the incoming clock signals sent from other stations and the clock signal of its own; means operatively connected to said detecting means for measuring said phase differences in a digital fashion; means operatively connected to said measuring means for computing the differences between said phase differences and a preset reference phase difference; means operatively connected to said computing means for weighting and averaging the outputs of said computing means, and means operatively connected to said weighting and averaging means for controlling the insertion or deletion of pulse groups into or from a reference clock pulse train in response to the output of said weighting and averaging means.
Claim 3
Dependent Claim
21 words
The system of claim 1, further comprising means operatively connected to said controlling means for smoothing the output pulse train thereof.
Claim 4
Dependent Claim
26 words
The system of claim 1, further comprising means operatively interposed between said measuring means and said computing means for memorizing the outputs of said measuring means.
Claim 5
Dependent Claim
13 words
The system of claim 3, in which said measuring means comprises counting means.
Claim 6
Dependent Claim
46 words
The system of claim 4, in which said computing means comprises means for judging whether the output of said counting means is greater than, equal to, or less than said reference phase difference and for deriving a characteristic output signal as a result of said judging.
Claim 7
Dependent Claim
43 words
The system of claim 5, in which said weighting and measuring means comprises means for sensing the characteristic output signals from said computing means and to derive a control signal according to which of said characteristic output signals is of the greatest number.
Claim 8
Dependent Claim
36 words
The system of claim 1, in which said detecting means, said measuring means, said computing means, said weighting and averaging means, said controlling means, and said smoothing means, are all in the form of digital circuits.
Claim 9
Dependent Claim
39 words
The system of claim 6, in which said detecting means, said measuring means, said memorizing means, said computing means, said weighting and averaging means, said controlling means, and said smoothing means, are all in the form of digital circuits.
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) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |