US3838415A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data modem apparatus
Assignee: Collins Radio Co
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Filing: 1973-05-16
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Granted: 1974-09-24
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Expires: 1993-05-16
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
2026-10-28 07:43
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/02; H04L5/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
130 words
Decoding apparatus for use in converting three digital logic level sources representative of phase updated angles in a communication system to a three channel data output comprising in combination: first, second, and third digital sources indicative in the logic 1 condition of 180*, 90*, and 45*, respeCtively; first, second, and third data storage units for storing the phase angle to channel data information, respectively; means connecting said first digital source to said second storage means for transfer of the logic level in the first source to the second storage means; first exclusive NOR gate means connecting the outputs of said second and first digital sources to said first storage means; and second exclusive NOR means connecting the outputs of said second and third digital sources to said third storage means.
Claim 2
Dependent Claim
130 words
Decoding apparatus for use in converting three digital logic level sources representative of phase updated angles in a communication system to a three channel data output comprising in combination: first, second, and third digital sources indicative in the logic 1 condition of 180*, 90*, and 45*, respeCtively; first, second, and third data storage units for storing the phase angle to channel data information, respectively; means connecting said first digital source to said second storage means for transfer of the logic level in the first source to the second storage means; first exclusive NOR gate means connecting the outputs of said second and first digital sources to said first storage means; and second exclusive NOR means connecting the outputs of said second and third digital sources to said third storage 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) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |