US3564415A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Backward acting compandor in a digital transmission system
Assignee: AT&T Inc
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Filing: 1968-04-03
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Granted: 1971-02-16
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Expires: 1988-04-03
Abstract
Abstract A DIGITAL TRANSMISSION SYSTEM IS DISCLOSED UTILIZING BACKWARD ACTING COMPANDING. A VARIABLE SIZE STEP PULSE SOURCE IS USED AT THE MODULATOR TO ACHIEVE COMPRESSION AND ANOTHER IS USED AT THE DEMODULATOR TO ACHIEVE COMPELEMENTARY EXPANSION. MEANS LOCATED AT THE DEMODULATOR RESPONSIVE TO A PARAMETER OF THE TRANSMITTED MESSAGE WAVEFORM ARE USED TO DETERMINED THE AMPLITUDE OF THE VARIABLE SIZE STEP PULSE PRODUCED AT THE REMOTELY LOCATED MODULATOR AND AT THE DEMODULATOR.
Inventors
- 👤 Stephen J Brolin
- 👤 James M Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:32
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04; H04B; H04B14/00; H04B14/02; H04B14/06; H04B14/062; H04B14/064
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |