US3842352A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Communications system having single rf channel diversity means
Assignee: United States Department of the Air Force
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Filing: 1972-07-14
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Granted: 1974-10-15
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Expires: 1992-07-14
Abstract
Abstract Time diversity utilizing a single RF channel is achieved by duplicating the information bearing signal to be transmitted, delaying one duplicate signal, multiplexing the delayed and undelayed signals on an RF carrier and transmitting the multiplexed signal to a remote receiving station. At the receiving station the received signal is demultiplexed and the undelayed duplicate signal is delayed to bring it into time coincidence with the delayed duplicate signal. Subsequent combining of these signals provides a signal that is not subject to information loss due to fade or other interference for periods equal to or less than the delay time. A third delayed duplicate signal is also comprehended that obviates the effects of short and intermittent recovery time. In the preferred embodiment analog signals are transmitted by apparatus utilizing audio frequency delay lines and frequency division multiplexers and demultiplexers.
Inventors
- 👤 W Cote
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:17
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/08; H04B; H04B7/00; H04B7/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
231 words
A communications system comprising at a transmitting station; a signal source, first, second and third transmission lines, each said transmission line being connected to receive simultaneously signals generated by said signal source, a first time delay means disposed in said second transmission line, a second time delay means disposed in said third transmission line, a multiplexer adapted to multiplex the signals on each transmission line onto a signal RF carrier; and a communications transmitter connected to the output thereof for transmitting said multiplexed signals to a remote receiving station, and at said remote receiving station, a communications receiver adapted to receive said transmitted multiplexed signals, a demultiplexer connected thereto, a fourth transmission line connected to the output of said demultiplexer to receive undelayed demultiplexed signals, fifth and sixth transmission lines connected to the output of said demultiplexer to receive delayed demultiplexed signals, a third time delay means disposed in said fourth transmission line, means for combining the signals on said fourth and fifth transmission lines, a seventh transmission line connEcted to receive the combined signals of said fourth and fifth transmission lines, a fourth time delay means disposed in said seventh transmission line, said third and fourth time delay means being adapted to bring the demultiplexed signals on said fourth, fifth and sixth transmission line into time coincidence, and means for combining the signals on said sixth and seventh transmission lines.
Claim 2
Dependent Claim
231 words
A communications system comprising at a transmitting station; a signal source, first, second and third transmission lines, each said transmission line being connected to receive simultaneously signals generated by said signal source, a first time delay means disposed in said second transmission line, a second time delay means disposed in said third transmission line, a multiplexer adapted to multiplex the signals on each transmission line onto a signal RF carrier; and a communications transmitter connected to the output thereof for transmitting said multiplexed signals to a remote receiving station, and at said remote receiving station, a communications receiver adapted to receive said transmitted multiplexed signals, a demultiplexer connected thereto, a fourth transmission line connected to the output of said demultiplexer to receive undelayed demultiplexed signals, fifth and sixth transmission lines connected to the output of said demultiplexer to receive delayed demultiplexed signals, a third time delay means disposed in said fourth transmission line, means for combining the signals on said fourth and fifth transmission lines, a seventh transmission line connEcted to receive the combined signals of said fourth and fifth transmission lines, a fourth time delay means disposed in said seventh transmission line, said third and fourth time delay means being adapted to bring the demultiplexed signals on said fourth, fifth and sixth transmission line into time coincidence, and means for combining the signals on said sixth and seventh transmission lines.
Claim 3
Dependent Claim
17 words
A communications system as defined in claim 1 wherein said signal source generates information bearing analog signals.
Claim 4
Dependent Claim
24 words
A communications system as defined in claim 2 wherein said multiplexer is a frequency division multiplexer and said demultiplexer is a frequency division demultiplexer.
Claim 5
Dependent Claim
23 words
A communications system as defined in claim 3 wherein said first, second, third and fourth time delay means are audio frequency delay lines.
Claim 6
Dependent Claim
72 words
A communications system as defined in claim 4 wherein said first and third time delay means are audio frequency delay lines having delay times in the region of 5 milliseconds, said second delay means is an audio frequency delay line having a delay time in the region of 100 milliseconds and said fourth time delay means is an audio frequency delay line having a delay time in the region of 95 milliseconds.
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) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |