US3663754A
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Communication system having modulator for generating orthogonal continuous phase synchronous binary fsk
Assignee: TOTUUS COMMUNICATIONS Inc
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Filing: 1970-05-18
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Granted: 1972-05-16
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Expires: 1990-05-18
Abstract
Abstract A communication system includes a modulator that generates orthogonal continuous phase synchronous binary frequency shift keying signals derived from a single oscillator without narrowband filters. Digital countdown chains are used to derive all appropriate signals. A transmitter incorporating the modulator and a receiver are also disclosed.
Inventors
- 👤 Drexel W Hanna Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:33
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/10; H04L27/12; H04L27/122
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
125 words
Apparatus for generating two or more tones having a known frequency separation, comprising only one oscillator for generating a clock signal, means for deriving at least two signals at different frequencies from said oscillator, means for shifting the phase of each derived signal and thereby generating signals proportional to the sine function and cosine function of each signal, means for mixing the cosine function signals of said phase shifted signals, means for mixing the sine function signals of said phase shifted signals, means for summing said mixed signals, means for shifting the phase of said mixed sine signal by 180*, means for summing said phase shifted mixed sine signal and said mixed cosine signal to derive signal frequency signals as a result of the combination.
Claim 2
Dependent Claim
125 words
Apparatus for generating two or more tones having a known frequency separation, comprising only one oscillator for generating a clock signal, means for deriving at least two signals at different frequencies from said oscillator, means for shifting the phase of each derived signal and thereby generating signals proportional to the sine function and cosine function of each signal, means for mixing the cosine function signals of said phase shifted signals, means for mixing the sine function signals of said phase shifted signals, means for summing said mixed signals, means for shifting the phase of said mixed sine signal by 180*, means for summing said phase shifted mixed sine signal and said mixed cosine signal to derive signal frequency signals as a result of the combination.
Claim 3
Dependent Claim
15 words
Apparatus in accordance with claim 1 including a gating circuit to select a desired frequency.
Claim 4
Dependent Claim
164 words
In a transmitter including a apparatus for generating orthogonal continuous phase synchronous binary frequency shift signals, said modulator having means for generating two or more tones having a known frequency separation using only one oscillator, means for deriving at least two signals at different frequencies from said oscillator, means for shifting the phase of each derived signal and thereby generating signals proportional to the sine function and the cosine function of each derived signal, means for mixing the cosine function signals of said phase shifted signals, means for mixing the sine function signals of said phase shifted signals, means for summing said mixed signals, means for shifting the phase of said mixed sine function signal by 180*, means for summing said phase shifted mixed sine function signal and said mixed cosine function signal to derive single frequency signals as a result of the combination, and means for providing a clock signal for synchronizing said signals and data signals to be received by said transmitter.
Claim 5
Dependent Claim
164 words
In a transmitter including a apparatus for generating orthogonal continuous phase synchronous binary frequency shift signals, said modulator having means for generating two or more tones having a known frequency separation using only one oscillator, means for deriving at least two signals at different frequencies from said oscillator, means for shifting the phase of each derived signal and thereby generating signals proportional to the sine function and the cosine function of each derived signal, means for mixing the cosine function signals of said phase shifted signals, means for mixing the sine function signals of said phase shifted signals, means for summing said mixed signals, means for shifting the phase of said mixed sine function signal by 180*, means for summing said phase shifted mixed sine function signal and said mixed cosine function signal to derive single frequency signals as a result of the combination, and means for providing a clock signal for synchronizing said signals and data signals to be received by said transmitter.
Claim 6
Dependent Claim
16 words
A transmitter in accordance with claim 3 wherein said clock signal is derived from said oscillator.
Claim 7
Dependent Claim
45 words
A transmitter in accordance with claim 3 including a message format generator, said message format generator comprising a pseudo-random generator and a preamble generator, gating means, the output of said message format generator and the output of said modulator being coupled into said gating means.
Claim 8
Dependent Claim
136 words
In a transmitter including a apparatus for generating orthogonal binary shift keying signals, said modulator including apparatus for generating two or more tones having known frequency separation comprising only one oscillator, means for deriving at least two signals at different frequencies from said oscillator, means for shifting the phase of each signal and thereby generate signals proportional to the sine function and the cosine function of each signal, means for mixing the cosine function signals of said phase shifted signals, means for mixing the sine function signals of said phase shifted signals, means for summing said mixed signals, means for shifting the phase of said mixed sine function signal by 180*, means for summing said phase shifted mixed sine signal and said mixed cosine signal to derive single frequency signals as a result of the combination.
Claim 9
Dependent Claim
136 words
In a transmitter including a apparatus for generating orthogonal binary shift keying signals, said modulator including apparatus for generating two or more tones having known frequency separation comprising only one oscillator, means for deriving at least two signals at different frequencies from said oscillator, means for shifting the phase of each signal and thereby generate signals proportional to the sine function and the cosine function of each signal, means for mixing the cosine function signals of said phase shifted signals, means for mixing the sine function signals of said phase shifted signals, means for summing said mixed signals, means for shifting the phase of said mixed sine function signal by 180*, means for summing said phase shifted mixed sine signal and said mixed cosine signal to derive single frequency signals as a result of the combination.
Claim 10
Dependent Claim
45 words
A transmitter in accordance with claim 6 including a message format generator, said message format generator comprising a pseudo-random generator and a preamble generator, gating means, the output of said message format generator and the output of said modulator being coupled into said gating means.
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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |