US4425639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Satellite communications system with frequency channelized beams
Assignee: AT&T Inc
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Filing: 1981-01-12
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Granted: 1984-01-10
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Expires: 2001-01-12
Abstract
Abstract A digital communications satellite (12,44) receives signals from a plurality of narrow input spot-beams (14) of an uplink. It regenerates, multiplexes and routes the signals for transmission in a plurality of narrow output spot-beams (42) of a downlink. The uplink beams (14) each include a plurality of frequency re-use channels (18), while the downlink beams (42) each have only a single wide-band channel. The satellite (12,44) may multiplex the signals either before or after routing them. The spot-beams (14,42) may be fixed or scanning.
Inventors
- 👤 Anthony Acampora
- 👤 Douglas O. Reudink
- 👤 Yu S. Yeh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:58
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/204; H04B7/2045
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
178 words
A communications system of the type including a plurality of accessing and receiving ground stations which communicate with each other via a satellite, the satellite comprising: means for receiving a plurality of digital uplink signals from the accessing ground stations, the uplink signals being received as a plurality of equal bandwidth spot-beams which each comprise a plurality of frequency-divided uplink channels; means for demodulating and regenerating the received uplink signals; means for routing the demodulated and regenerated signals between a set of input terminals and a set of output terminals to generate corresponding downlink signals; means for modulating and amplifying the downlink signals, and means for transmitting the downlink signals to the receiving ground stations, characterized by means for multiplexing the signals after regeneration to form high bit rate serial downlink signals as a plurality of equal-bandwidth downlink spot-beams equal to the number of uplink spotbeams, which downlink spotbeams each comprise at least one downlink frequency channel, there being a greater number of frequency-divided uplink channels per uplink spot-beam than there are downlink frequency channels per downlink spot-beam.
Claim 2
Dependent Claim
178 words
A communications system of the type including a plurality of accessing and receiving ground stations which communicate with each other via a satellite, the satellite comprising: means for receiving a plurality of digital uplink signals from the accessing ground stations, the uplink signals being received as a plurality of equal bandwidth spot-beams which each comprise a plurality of frequency-divided uplink channels; means for demodulating and regenerating the received uplink signals; means for routing the demodulated and regenerated signals between a set of input terminals and a set of output terminals to generate corresponding downlink signals; means for modulating and amplifying the downlink signals, and means for transmitting the downlink signals to the receiving ground stations, characterized by means for multiplexing the signals after regeneration to form high bit rate serial downlink signals as a plurality of equal-bandwidth downlink spot-beams equal to the number of uplink spotbeams, which downlink spotbeams each comprise at least one downlink frequency channel, there being a greater number of frequency-divided uplink channels per uplink spot-beam than there are downlink frequency channels per downlink spot-beam.
Claim 3
Dependent Claim
47 words
The system according to claim 1 wherein the downlink signals are transmitted as a plurality of spot-beams which each comprise only a single downlink frequency channel, the downlink frequency channel having a bandwidth equal to the combined bandwidth of the frequency-divided uplink channels in an uplink spot-beam.
Claim 4
Dependent Claim
31 words
The system according to claim 2 wherein the means for multiplexing are arranged to multiplex the uplink signals after they are regenerated and before they pass to the means for routing.
Claim 5
Dependent Claim
35 words
The system according to claim 2 wherein the means for multiplexing are arranged to multiplex the uplink signals after they are routed to the output terminals and before they pass to the means for modulating.
Claim 6
Independent Claim
30 words
The system according to claims 3 or 4 wherein the means for routing is capable of being dynamically reconfigured in accordance with the instantaneous signal traffic demand for the satellite.
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) | 1987-01-09 | 1987-07-11 | 1988-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-09 | 1991-07-11 | 1992-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-09 | 1995-07-11 | 1996-01-10 | $7700.00 | Window Closed / Lapsed |