Patent US3548066A successfully refreshed from Google Patents.
Patent US3737776A successfully refreshed from Google Patents.
US3737776A
Expired / Lapsed
US
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Two carrier communication system with single transmitter
Assignee: Individual
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Filing: 1971-06-09
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Granted: 1973-06-05
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Expires: 1991-06-09
Abstract
Abstract A pulse-code modulated communication system is disclosed for transmitting two subcarrier-modulated carriers from a single transmitter comprising two channels for phase modulating the two carriers independently. The modulating subcarriers are independently modulated by data and/or pseudonoise (PN) codes as desired. The modulated carriers are switched alternately to the single transmitter in synchronism with operation of a PN code generator when PN code modulation is present, as for ranging.
Inventors
- 👤 J Fletcher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:54
CPC Classifications
H; H04; H04B; H04B14/00; H04B14/08; H04L; H04L5/00; H04L5/02; H04L5/06
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
139 words
A multicarrier communication system comprising a transmitter, means for generating a clock signal, means for producing a plurality of independently modulated carrier signals, and means for cyclically switching to said transmitter each of said carrier signals in response to said clock signal, said means for proDucing said plurality of independently modulated carrier signals for each carrier signal comprising separate means for producing a subcarrier signal, means for biphase modulating said subcarrier signal with a unique data signal, wherein a pseudonoise code is added to said subcarrier, including means synchronized by said clock signal for generating said pseudonoise code in phase with the switching of said switching means, and means for adding said pseudonoise to said subcarrier, means for producing a carrier signal at a unique frequency, and means for phase modulating said carrier signal with said modulated subcarrier signal.
Claim 2
Dependent Claim
139 words
A multicarrier communication system comprising a transmitter, means for generating a clock signal, means for producing a plurality of independently modulated carrier signals, and means for cyclically switching to said transmitter each of said carrier signals in response to said clock signal, said means for proDucing said plurality of independently modulated carrier signals for each carrier signal comprising separate means for producing a subcarrier signal, means for biphase modulating said subcarrier signal with a unique data signal, wherein a pseudonoise code is added to said subcarrier, including means synchronized by said clock signal for generating said pseudonoise code in phase with the switching of said switching means, and means for adding said pseudonoise to said subcarrier, means for producing a carrier signal at a unique frequency, and means for phase modulating said carrier signal with said modulated subcarrier signal.
Claim 3
Dependent Claim
50 words
A multicarrier communications system as defined in claim 1 wherein said carrier signal for each modulated carrier is at a frequency equal to a desired carrier frequency divided by a number N, and said transmitter includes means for multiplying by said number N the frequencies of all modulated carriers transmitted.
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) | 1976-06-04 | 1976-12-04 | 1977-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-04 | 1980-12-04 | 1981-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-04 | 1984-12-04 | 1985-06-05 | $7700.00 | Window Closed / Lapsed |