US4130733A
Expired / Lapsed
US
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Frequency channel units for a FDM system
Assignee: International Telephone and Telegraph Corp
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Filing: 1977-01-10
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Granted: 1978-12-19
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Expires: 1997-01-10
Abstract
Abstract Each of the FDM frequency channel units of a FDM system include a physically programmable voltage controlled oscillator and a phase locked loop coupled therewith responsive to a reference signal or a physically programmable counter responsive to the reference signal. Each of these arrangements produce a carrier signal having a different predetermined frequency for each of a plurality of FDM frequency channel units. A balanced modulator modulates and transmits an associated one of the carrier signals with information and a balanced demodulator responsive to an associated one of the produced carrier signals demodulates an associated one of a plurality of received information bearing carrier signals.
Inventors
- 👤 Donald A. Ashford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:24
CPC Classifications
H; H04; H04J; H04J1/00; H04J1/02; H04J1/06
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
85 words
In a frequency division multiplex (FDM) system, a plurality of FDM frequency channel units each comprising: first means responsive to a single reference signal having a predetermined first frequency, said reference signal being coupled in common to all of said units to produce a carrier signal having a different predetermined second frequency in each of said units; and second means directly coupled to said first means and an audio input to modulate and to transmit an associated one of said carrier signals with audio information.
Claim 2
Dependent Claim
85 words
In a frequency division multiplex (FDM) system, a plurality of FDM frequency channel units each comprising: first means responsive to a single reference signal having a predetermined first frequency, said reference signal being coupled in common to all of said units to produce a carrier signal having a different predetermined second frequency in each of said units; and second means directly coupled to said first means and an audio input to modulate and to transmit an associated one of said carrier signals with audio information.
Claim 3
Dependent Claim
65 words
Channel units according to claim 1, wherein each of said first means includes a physically programmable voltage controlled oscillator to produce an associated one of said carrier signals for each of said units, and a phase locked loop coupled to said oscillator responsive to said reference signal to control said oscillator to maintain said associated one of carrier signals at said different predetermined second frequencies.
Claim 4
Dependent Claim
16 words
Channel units according to claim 2, wherein each of said second means includes a balanced modulator.
Claim 5
Dependent Claim
16 words
Channel units according to claim 1, wherein each of said second means includes a balanced modulator.
Claim 6
Dependent Claim
36 words
Channel units according to claim 1, wherein each of said first means includes a physically programmable counter responsive to said reference signal to produce an associated one of said carrier signals for each of said units.
Claim 7
Dependent Claim
16 words
Channel units according to claim 5, wherein each of said second means includes a balanced modulator.
Claim 8
Dependent Claim
49 words
Channel units according to claim 1, further including third means disposed in each of said units coupled to said first means responsive to an associated one of said carrier signals produced by said first means to demodulate an associated one of a plurality of received information bearing carrier signals.
Claim 9
Dependent Claim
65 words
Channel units according to claim 7, wherein each of said first means includes a physically programmable voltage controlled oscillator to produce an associated one of said carrier signals for each of said units, and a phase locked loop coupled to said oscillator responsive to said reference signal to control said oscillator to maintain said associated one of carrier signals at said different predetermined second frequencies.
Claim 10
Dependent Claim
16 words
Channel units according to claim 8, wherein each of said third means includes a balanced demodulator.
Claim 11
Dependent Claim
16 words
Channel units according to claim 8, wherein each of said second means includes a balance modulator.
Claim 12
Dependent Claim
16 words
Channel units according to claim 10, wherein each of said third means includes a balanced demodulator.
Claim 13
Dependent Claim
16 words
Channel units according to claim 7, wherein each of said second means includes a balanced modulator.
Claim 14
Dependent Claim
16 words
Channel units according to claim 7, wherein each of said third means includes a balanced demodulator.
Claim 15
Dependent Claim
36 words
Channel units according to claim 7, wherein each of said first means includes a physically programmable counter responsive to said reference signal to produce an associated one of said carrier signals for each of said units.
Claim 16
Dependent Claim
16 words
Channel units according to claim 14, wherein each of said second means includes a balanced modulator.
Claim 17
Dependent Claim
114 words
In a frequency division multiplex (FDM) system, a plurality of FDM frequency channel units each comprising: first means responsive to a single reference signal having a predetermined first frequency, said reference signal being coupled in common to all of said units to produce a carrier signal having a different predetermined second frequency in each of said units; and second means coupled to said first means to modulate and to transmit an associated one of said carrier signals with information a group of said units providing a FDM channel pregroup, and the remainder of said units being coupled to each of said units of said group of said units to provide a FDM channel group.
Claim 18
Dependent Claim
114 words
In a frequency division multiplex (FDM) system, a plurality of FDM frequency channel units each comprising: first means responsive to a single reference signal having a predetermined first frequency, said reference signal being coupled in common to all of said units to produce a carrier signal having a different predetermined second frequency in each of said units; and second means coupled to said first means to modulate and to transmit an associated one of said carrier signals with information a group of said units providing a FDM channel pregroup, and the remainder of said units being coupled to each of said units of said group of said units to provide a FDM channel group.
Claim 19
Dependent Claim
60 words
Channel units according to claim 16, further including third means disposed in each of said units coupled to said first means responsive to an associated one of said carrier signals produced by said first means to demodulate an associated information bearing channel of a received FDM channel group and an associated information bearing channel of a received FDM channel pregroup.
Claim 20
Dependent Claim
87 words
In a frequency division multiplex (FDM) system, a plurality of FDM frequency channel units each comprising: first means responsive to a single reference signal having a predetermined first frequency, said reference signal being coupled in common to all of said units to produce a carrier signal having a different predetermined second frequency in each of said units; and second means coupled to said first means to modulate and to transmit an associated one of said carrier signals with information said units directly providing a FDM channel group.
Claim 21
Dependent Claim
87 words
In a frequency division multiplex (FDM) system, a plurality of FDM frequency channel units each comprising: first means responsive to a single reference signal having a predetermined first frequency, said reference signal being coupled in common to all of said units to produce a carrier signal having a different predetermined second frequency in each of said units; and second means coupled to said first means to modulate and to transmit an associated one of said carrier signals with information said units directly providing a FDM channel group.
Claim 22
Dependent Claim
48 words
Channel units according to claim 18, further including third means disposed in each of said units coupled to said first means responsive to an associated one of said carrier signals produced by said first means to demodulate an associated information bearing channel of a received FDM channel group.
Claim 23
Dependent Claim
109 words
In a frequency division multiplex (FDM) system, a plurality of FDM frequency channel units each comprising: first means responsive to a single reference signal having a predetermined first frequency, said reference signal being coupled in common to all of said units to produce a carrier signal having a different predetermined second frequency in each of said units; and second means coupled to said first means to modulate and to transmit an associated one of said carrier signals with information. one of said units providing a single FDM premodulation channel, and the remainder of said units being coupled to said one of said units to provide a FDM channel group.
Claim 24
Dependent Claim
109 words
In a frequency division multiplex (FDM) system, a plurality of FDM frequency channel units each comprising: first means responsive to a single reference signal having a predetermined first frequency, said reference signal being coupled in common to all of said units to produce a carrier signal having a different predetermined second frequency in each of said units; and second means coupled to said first means to modulate and to transmit an associated one of said carrier signals with information. one of said units providing a single FDM premodulation channel, and the remainder of said units being coupled to said one of said units to provide a FDM channel group.
Claim 25
Dependent Claim
60 words
Channel units according to claim 20, further including third means disposed in each of said units coupled to said first means responsive to an associated one of said carrier signals produced by said first means to demodulate an associated information bearing channel of a received FDM channel group and a single information bearing channel of a received FDM premodulation channel.
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) | 1981-12-18 | 1982-06-19 | 1982-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-18 | 1986-06-19 | 1986-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-18 | 1990-06-19 | 1990-12-19 | $7700.00 | Window Closed / Lapsed |