Patent US3649256A successfully refreshed from Google Patents.
US3597547A
Expired / Lapsed
US
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Apparatus for synchronizing a pcm-receiver and a transmitter
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1969-02-06
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Granted: 1971-08-03
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Expires: 1989-02-06
Abstract
Abstract A method for synchronizing the receiver and the transmitter in a PCM-receiver system wherein binary information is transmitted within cyclically occurring channels. The last bit of each of the channels form a synchronization pattern, which is regular but has at least one irregularity which occurs within a predetermined channel. By first using the regular part of the synchronization pattern for synchronizing the bit distributors of the transmitter and the receiver and then the irregularity for synchronizing the channel distributors a very fast two stage synchronization process is obtained.
Inventors
- 👤 Johan Nils Roll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:49
CPC Classifications
H; H04; H04J; H04J3/00; H04J3/02; H04J3/06; H04J3/0602; H04J3/0605
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
286 words
In a time division multiplex system having a transmitting terminal and a receiving terminal, wherein said receiving terminal includes a bit and a channel distributor and said transmitting terminal transmits a pulse train which includes binary coded pulses grouped in cyclically occurring channels and binary synchronizing pulses assigned to definite bit positions within said cyclically occurring channels, said synchronizing pulses forming a regular recurrent pattern in which irregularities are provided by means of a second superimposed regular recurrent pattern, said first pattern being employed for restoring synchronism of said bit distributor and said superimposed pattern being employed for restoring synchronism of said channel distributor of said receiving terminal, a synchronism restoring arrangement comprising means operative in response to said bit distributor for normally generating pulses which are synchronous with respect to said synchronizing pulses, means operative in response to said channel distributor for normally in predetermined channels, inhibiting said synchronous pulses to create a local pulse train which is synchronous with respect to said synchronizing pulses and having the same recurrent pattern, means for comparing the timing of said local pulse train with respect to said synchronizing pulses, means operative in response to a loss of synchronism between said local pulse train and said synchronizing pulses for intermittently interrupting said bit distributor until synchronism is restored, means for interrupting said channel distributor until a synchronizing pulse which is part of said superimposed pattern is received after synchronism of said bit distributor has occurred over a predetermined number of successive channels, and means for setting said channel distributor to receive a definite channel when said interruption ceases, said definite channel being the channel following the channel of said synchronizing pulse which is part of said superimposed pattern.
Claim 2
Dependent Claim
286 words
In a time division multiplex system having a transmitting terminal and a receiving terminal, wherein said receiving terminal includes a bit and a channel distributor and said transmitting terminal transmits a pulse train which includes binary coded pulses grouped in cyclically occurring channels and binary synchronizing pulses assigned to definite bit positions within said cyclically occurring channels, said synchronizing pulses forming a regular recurrent pattern in which irregularities are provided by means of a second superimposed regular recurrent pattern, said first pattern being employed for restoring synchronism of said bit distributor and said superimposed pattern being employed for restoring synchronism of said channel distributor of said receiving terminal, a synchronism restoring arrangement comprising means operative in response to said bit distributor for normally generating pulses which are synchronous with respect to said synchronizing pulses, means operative in response to said channel distributor for normally in predetermined channels, inhibiting said synchronous pulses to create a local pulse train which is synchronous with respect to said synchronizing pulses and having the same recurrent pattern, means for comparing the timing of said local pulse train with respect to said synchronizing pulses, means operative in response to a loss of synchronism between said local pulse train and said synchronizing pulses for intermittently interrupting said bit distributor until synchronism is restored, means for interrupting said channel distributor until a synchronizing pulse which is part of said superimposed pattern is received after synchronism of said bit distributor has occurred over a predetermined number of successive channels, and means for setting said channel distributor to receive a definite channel when said interruption ceases, said definite channel being the channel following the channel of said synchronizing pulse which is part of said superimposed pattern.
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 |