US3764743A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data modem apparatus
Assignee: Collins Radio Co
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Filing: 1971-10-08
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Granted: 1973-10-09
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Expires: 1991-10-08
Abstract
Abstract Apparatus for and the method of providing three channel, eight phase data modulation and demodulation whereby the system may be used for either two or three channels with no detrimental effects in either mode of operation due to the additional circuitry. The invention discloses additional apparatus for connection to a conventional two channel, four phase system to produce a three channel, eight phase system. The coding of the eight phase system modifies the basic phase change of a two channel, four phase system by + OR - 22.5* depending upon the inclusive OR result of the first two channels as compared to the binary logic level of the third channel.
Inventors
- 👤 W Melvin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:11
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/02; H04L5/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
339 words
Phase coding logic means for use in an eight-phase modulating and transmitting system comprising, in combination: first, second, and third binary logic means for providing binary data indications of first, second, and third channels, respectively; first, exclusive NOR logic means connected to said first and second data sources and providing an exclusive NOR output indicative of data received from said first and second sources; first, second, third, and fourth pulse timing source means each indicative of different phase relationships; AND gate means connected to receive the output from said first exclusive NOR means and to receive said third pulse timing signal and for providing an output; second AND gate means connected to said second binary logic means for receiving signals therefrom and further connected to said fourth pulse timing source means for receiving signals therefrom and for providing a second output; OR gate means connected to said first and second AND gates and to said second pulse timing source means for receiving signals therefrom and providing an output; inverting exclusive NOR means connected to the output of said first exclusive NOR means for inverting and exclusive NORing the output therefrom with an output received from said third data source means, said inverting exclusive NOR means providing an output indicative of the received signals; third AND gate means connected to said second, third, and fourth pulse timing source means for receiving timing signals therefrom and connected to said inverting exclusive NOR means for receiving signals therefrom, said third AND gate means providing outputs indicative of the simultaneous occurrence of the output from said inverting exclusive NOR gate means and any one of said signals from second, third, and fourth pulse timing source means; second OR gate means connected for receiving outputs from said third AND gate means and from said first pulse timing source means and for providing outputs indicative thereof; and full adder means connected for receiving the output signals from said first and second OR gate means and providing an output indicative of the full binary addition thereof.
Claim 2
Dependent Claim
339 words
Phase coding logic means for use in an eight-phase modulating and transmitting system comprising, in combination: first, second, and third binary logic means for providing binary data indications of first, second, and third channels, respectively; first, exclusive NOR logic means connected to said first and second data sources and providing an exclusive NOR output indicative of data received from said first and second sources; first, second, third, and fourth pulse timing source means each indicative of different phase relationships; AND gate means connected to receive the output from said first exclusive NOR means and to receive said third pulse timing signal and for providing an output; second AND gate means connected to said second binary logic means for receiving signals therefrom and further connected to said fourth pulse timing source means for receiving signals therefrom and for providing a second output; OR gate means connected to said first and second AND gates and to said second pulse timing source means for receiving signals therefrom and providing an output; inverting exclusive NOR means connected to the output of said first exclusive NOR means for inverting and exclusive NORing the output therefrom with an output received from said third data source means, said inverting exclusive NOR means providing an output indicative of the received signals; third AND gate means connected to said second, third, and fourth pulse timing source means for receiving timing signals therefrom and connected to said inverting exclusive NOR means for receiving signals therefrom, said third AND gate means providing outputs indicative of the simultaneous occurrence of the output from said inverting exclusive NOR gate means and any one of said signals from second, third, and fourth pulse timing source means; second OR gate means connected for receiving outputs from said third AND gate means and from said first pulse timing source means and for providing outputs indicative thereof; and full adder means connected for receiving the output signals from said first and second OR gate means and providing an output indicative of the full binary addition thereof.
Claim 3
Dependent Claim
171 words
Logic means for providing binary output signals indicative of phase vectors having given angular relationships with respect to a reference comprising, in combination: first, second, and third binary data source representing, respectively, first, second, and third channels; first binary logic means connected to said first and second data sources for providing time multiplexed binary output signals indicative of +135* and -45* corresponding respectively to two states when the data in said first and second channels are alike and +45* and -135* corresponding respectively to two further states when the data are different; second logic means connected to said third binary data source and to said first logic means for modifying the output of said first logic means by +22.5* when the binary data of said third channel equals the exclusive NOR of the binary data from said first and second channels and modifying said output by -22.5* when the binary data from said third channel is different from the exclusive NOR of the binary data from said first and second channels.
Claim 4
Dependent Claim
171 words
Logic means for providing binary output signals indicative of phase vectors having given angular relationships with respect to a reference comprising, in combination: first, second, and third binary data source representing, respectively, first, second, and third channels; first binary logic means connected to said first and second data sources for providing time multiplexed binary output signals indicative of +135* and -45* corresponding respectively to two states when the data in said first and second channels are alike and +45* and -135* corresponding respectively to two further states when the data are different; second logic means connected to said third binary data source and to said first logic means for modifying the output of said first logic means by +22.5* when the binary data of said third channel equals the exclusive NOR of the binary data from said first and second channels and modifying said output by -22.5* when the binary data from said third channel is different from the exclusive NOR of the binary data from said first and second channels.
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) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |