US4833696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for controlling operation mode of modulator/demodulator
Assignee: NEC Corp
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Filing: 1986-04-02
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Granted: 1989-05-23
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Expires: 2006-04-02
Abstract
Abstract A modulator/demodulator operation mode control system specifies an operation mode, which is a combination of particular data transmission rate, multi-phase PSK modulation system, error-correction coding rate and others, in which a modulator/demodulator is to operate, while deciding the operation mode and controlling the modulator/demodulator. A transmit station designates a particular operation mode in a plurality of bits in terms of polarities of unique words, while a receive station switches a demodulator thereof to the designated operation mode responsive to an output of mode switchover signal decision means and based on signal representative of detection of the unique words.
Inventors
- 👤 Osamu Ichiyoshi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:32
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/14; H04L5/1438; H04L27/00; H04L27/18; H04L27/22
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
201 words
A system for controlling an operation mode of a modulator/demodulator, said modulator/demodulator operating in one of a plurality of operation modes in accordance with at least a data transmission rate, an error-correction coding rate, and multi-phase shift keying modulation conditions, said system comprising: means for receiving a first signal which contains traffic data and a switchover signal, said switchover signal including K unique digital words indicative of a desired one of said operation modes of said modulator/demodulator, where K is a positive integer, and a synchronizing unique word, wherein each of said unique digital words and said synchronizing unique word is L bits long, where L is a positive integer, K and L being sufficiently large that a unique word detection error rate is sufficiently lower than a bit error rate to enable accurate detection even in poor signal-to-noise conditions; means for detecting said K unique digital words and outputting a detection signal when one of said K unique digital words is received; and means, responsive to said detection signal, for altering said operation mode of said modulator/demodulator, wherein said operation mode is controlled in a manner substantially unaffected by adverse signal-to-noise ratio conditions under which said first signal is transmitted.
Claim 2
Independent Claim
201 words
A system for controlling an operation mode of a modulator/demodulator, said modulator/demodulator operating in one of a plurality of operation modes in accordance with at least a data transmission rate, an error-correction coding rate, and multi-phase shift keying modulation conditions, said system comprising: means for receiving a first signal which contains traffic data and a switchover signal, said switchover signal including K unique digital words indicative of a desired one of said operation modes of said modulator/demodulator, where K is a positive integer, and a synchronizing unique word, wherein each of said unique digital words and said synchronizing unique word is L bits long, where L is a positive integer, K and L being sufficiently large that a unique word detection error rate is sufficiently lower than a bit error rate to enable accurate detection even in poor signal-to-noise conditions; means for detecting said K unique digital words and outputting a detection signal when one of said K unique digital words is received; and means, responsive to said detection signal, for altering said operation mode of said modulator/demodulator, wherein said operation mode is controlled in a manner substantially unaffected by adverse signal-to-noise ratio conditions under which said first signal is transmitted.
Claim 3
Dependent Claim
71 words
A system as claimed in claim 1, wherein said means for altering said operation mode comprises: means for determining whether more than a predetermined number of said unique digital words have been received and for detecting a switchover of operation modes when said predetermined number have been received; and means for selecting a particular one of said plurality of operation modes in accordance with an output of said switchover detection means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |