EP0050478A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Satellite communications system and apparatus
Assignee: Spacenet Inc
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Filing: 1981-10-15
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Granted: —
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Expires: 2001-10-15
Abstract
Abstract A satellite communications system, which is inherently power limited, employing spread spectrum techniques in order to trade-off bandwidth for small ground station antennas. In a one-way system embodiment a central station (14) transmits data to a satellite (3) for relay to a large number of small antenna receiving stations (4), the transmissions being spread spectrum encoded with spreading code lengths selected to provide adequate data recovery at the least sensitive station to which the transmissions are directed. Spreading codes may also function to address particular stations. In a two-way system embodiment, the central station (14) additionally functions as a terrestrial relay station. A plurality of small antenna transmitting stations, at least one of which may be at the same site as a receiving station, transmit code division multiplexed data via the satellite to the central relay station using sufficiently long and distinct spreading codes as to permit adequate data error rates and to distinguish the transmissions of the various stations. The central relay station reformats the received data for retransmission to the satellite for relay to the receiving stations.
Inventors
- 👤 Paul Baran
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 22:13
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/204; H04B7/216; Y; Y02; Y02D; Y02D30/00; Y02D30/70
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
120 words
An earth satellite communications system for transmitting data from a plurality of users through a repeating satellite to a plurality of receiving stations, comprising A central transmitting station receiving data from a plurality of users, said station including means for converting the format of said data into a form suitable for transmission to a satellite, means for spread spectrum processing the converted data, and means for transmitting the spread spectrum processed converted data to a satellite, and A plurality of receiving stations, each of said receiving stations including wide beamwidth, low gain antenna means, detection means coupled to said antenna means, said detection means including spread spectrum processing means, for recovering data sent to said receiving station via said satellite.
Claim 2
Dependent Claim
120 words
An earth satellite communications system for transmitting data from a plurality of users through a repeating satellite to a plurality of receiving stations, comprising A central transmitting station receiving data from a plurality of users, said station including means for converting the format of said data into a form suitable for transmission to a satellite, means for spread spectrum processing the converted data, and means for transmitting the spread spectrum processed converted data to a satellite, and A plurality of receiving stations, each of said receiving stations including wide beamwidth, low gain antenna means, detection means coupled to said antenna means, said detection means including spread spectrum processing means, for recovering data sent to said receiving station via said satellite.
Claim 3
Dependent Claim
26 words
The combination of claim 1 wherein said detection means further includes means for converting the format of said data into a form suitable for a user.
Claim 4
Dependent Claim
34 words
The combination of claim 1 wherein said antenna means includes an antenna having a half-power beamwidth wider than the standard orbital spacing of satellites, whereby said antenna receives signals from more than one satellite.
Claim 5
Dependent Claim
35 words
The combination of claims 1 or 3 wherein said antenna means includes an antenna having a gain providing a signal level below the thermal noise floor when standard (nonspread spectrum) satellite modulation techniques are used.
Claim 6
Dependent Claim
24 words
The combination of claim 1 wherein said antenna means includes a dish antenna having a diameter on the order of two feet or less.
Claim 7
Dependent Claim
23 words
The combination of claim 1 wherein said antenna means includes an antenna having a gain in the order of 26 dB or less.
Claim 8
Dependent Claim
35 words
The combination of claim 1 wherein said spread spectrum processing means in said receiving stations includes means storing a local reference code for comparison to signals received for recovering data sent to said receiving station.
Claim 9
Dependent Claim
24 words
The combination of claims 1 or 7 wherein said spread spectrum processing means includes means for synchronizing said processing means to the received signals.
Claim 10
Dependent Claim
32 words
The combination of claim 1 wherein said spread spectrum processing means in said central station includes means for processing data for particular receiving stations with a spreading code unique to such stations.
Claim 11
Dependent Claim
46 words
The combination of claims 1 or 9 wherein said spectrum processing means in said central station includes means for processing data for particular receiving stations with a spreading code having a length commensurate with the sensitivity of the least sensitive station among said particular receiving stations.
Claim 12
Dependent Claim
20 words
The combination of claims 1 or 9 wherein said means for transmitting transmits said data in a time division format.
Claim 13
Dependent Claim
31 words
The combination of claim 9 wherein said means for transmitting transmits data in a time division format, wherein data processed by each unique spreading code occupies the next available time slot.
Claim 14
Dependent Claim
55 words
In an earth satellite communications system, wherein the signals relayed from the satellite are power limited spread spectrum signals, a receiving station comprising wide beamwidth, low gain antenna means, detection means coupled to said antenna means, said detection means including spread spectrum processing means, for recovering data sent to said receiving station via said satellite.
Claim 15
Dependent Claim
55 words
In an earth satellite communications system, wherein the signals relayed from the satellite are power limited spread spectrum signals, a receiving station comprising wide beamwidth, low gain antenna means, detection means coupled to said antenna means, said detection means including spread spectrum processing means, for recovering data sent to said receiving station via said satellite.
Claim 16
Dependent Claim
26 words
The combination of claim 13 wherein said detection means further includes means for converting the format of said data into a form suitable for a user.
Claim 17
Dependent Claim
34 words
The combination of claim 13 wherein said antenna means includes an antenna having a half-power beamwidth wider than the standard orbital spacing of satellites, whereby said antenna receives signals from more than one satellite.
Claim 18
Dependent Claim
35 words
The combination of claims 13 or 15 wherein said antenna means includes an antenna having a gain providing a signal level below the thermal noise floor when standard (nonspread spectrum) satellite modulation techniques are used.
Claim 19
Dependent Claim
24 words
The combination of claim 13 wherein said antenna means includes a dish antenna having a diameter on the order of two feet or less.
Claim 20
Dependent Claim
23 words
The combination of claim 13 wherein said antenna means includes an antenna having a gain in the order of 26 dB or less.
Claim 21
Dependent Claim
31 words
The combination of claim 13 wherein said spread spectrum processing means includes means storing a local reference code for comparison to signals received for recovering data sent to said receiving station.
Claim 22
Dependent Claim
24 words
The combination of claims 13 or 19 wherein said spread spectrum processing means includes means for synchronizing said processing means to the received signals.
Claim 23
Dependent Claim
61 words
In an earth satellite communications system having a plurality of receiving stations, a transmitting station receiving data from a plurality of users, comprising means for converting the format of said data into a form suitable for transmission to a satellite, means for spread spectrum processing the converted data, and means for transmitting the spread spectrum processed converted data to a satellite.
Claim 24
Dependent Claim
61 words
In an earth satellite communications system having a plurality of receiving stations, a transmitting station receiving data from a plurality of users, comprising means for converting the format of said data into a form suitable for transmission to a satellite, means for spread spectrum processing the converted data, and means for transmitting the spread spectrum processed converted data to a satellite.
Claim 25
Dependent Claim
32 words
The combination of claim 21 wherein said spread spectrum processing means in said transmitting station includes means for processing data for particular receiving stations with a spreading code unique to such stations.
Claim 26
Dependent Claim
47 words
The combination of claims 21 or 22 wherein said spread spectrum processing means in said transmitting station includes means for processing data for particular receiving stations with a spreading code having a length commensurate with the sensitivity of the least sensitive station among said particular receiving stations.
Claim 27
Dependent Claim
20 words
The combination of claims 21 or 22 wherein said means for transmitting transmits said data in a time division format.
Claim 28
Dependent Claim
31 words
The combination of claim 22 wherein said means for transmitting transmits data in a time division format, wherein data processed by each unique spreading code occupies the next available time slot.
Claim 29
Dependent Claim
164 words
An earth satellite communications system wherein a plurality of stations transmit data through a satellite and a terrestrial relay station to a plurality of receiving stations, the combination comprising a plurality of transmitting stations, each comprising means receiving data for transmission to a satellite, means for spread spectrum processing said data, and means for transmitting said spread spectrum processed data to said satellite, said transmitting means including wide beamwidth, low gain antenna means, and a terrestrial relay station, comprising antenna means, detection means coupled to said antenna means, said detection means including spread spectrum processing means for recovering data sent by said transmitting station, means for spread spectrum processing the recovered data, and means for transmitting the spread spectrum processed data to said satellite, and a plurality of receiving stations, each comprising wide beamwidth, low gain antenna means, detection means coupled to said antenna means, said detection means including spread spectrum processing means, for recovering data sent to said receiving station via said satellite.
Claim 30
Dependent Claim
164 words
An earth satellite communications system wherein a plurality of stations transmit data through a satellite and a terrestrial relay station to a plurality of receiving stations, the combination comprising a plurality of transmitting stations, each comprising means receiving data for transmission to a satellite, means for spread spectrum processing said data, and means for transmitting said spread spectrum processed data to said satellite, said transmitting means including wide beamwidth, low gain antenna means, and a terrestrial relay station, comprising antenna means, detection means coupled to said antenna means, said detection means including spread spectrum processing means for recovering data sent by said transmitting station, means for spread spectrum processing the recovered data, and means for transmitting the spread spectrum processed data to said satellite, and a plurality of receiving stations, each comprising wide beamwidth, low gain antenna means, detection means coupled to said antenna means, said detection means including spread spectrum processing means, for recovering data sent to said receiving station via said satellite.
Claim 31
Dependent Claim
41 words
The combination of claim 26 wherein said terrestrial relay station receives additional data from terrestrial sources for transmission to said satellite, said spread spectrum processing means further processing said additional data and said transmitting means further transmitting said processed additional data.
Claim 32
Dependent Claim
21 words
The combination of claim 26 wherein said transmitting station transmitting means transmits on different frequencies from said relay station transmitting means.
Claim 33
Dependent Claim
33 words
The combination of claims 26 or 28 wherein said transmitting station transmitting means transmits in a code division multiplex format and said relay station transmitting means transmits in a time division multiplex format.
Claim 34
Dependent Claim
36 words
The combination of claim 28 wherein there are a plurality of transmitting stations and a plurality of receiving stations, and at least one pair of transmitting and receiving stations are located at the same geographic site.
Claim 35
Dependent Claim
18 words
The combination of claim 30 wherein each transmitting station has a unique spreading code or pair of codes.
Claim 36
Dependent Claim
35 words
The combination of claims 30 or 31 wherein said means for spread spectrum processing in said relay station includes means for processing data for particular receiving stations with a spreading code unique to such stations.
Claim 37
Dependent Claim
47 words
In an earth satellite communications system, a transmitting station comprising means receiving data for transmission to a satellite, means for spread spectrum processing said data, and means for transmitting said spread spectrum processed data to said satellite, said transmitting means including wide beamwidth, low gain antenna means.
Claim 38
Dependent Claim
47 words
In an earth satellite communications system, a transmitting station comprising means receiving data for transmission to a satellite, means for spread spectrum processing said data, and means for transmitting said spread spectrum processed data to said satellite, said transmitting means including wide beamwidth, low gain antenna means.
Claim 39
Dependent Claim
63 words
The combination of claim 33 wherein said station is one of a plurality of stations transmitting to said satellite in a particular frequency channel, said means for spread spectrum processing including means for processing-said data with a spreading code unique to said station and substantially orthogonal to spreading codes employed by other stations in said channel, whereby code division multiplex transmission is effected.
Claim 40
Dependent Claim
26 words
The combination of claims 33 or 34 wherein the length of said spreading code is sufficient to overcome the effects of said low gain antenna means.
Claim 41
Dependent Claim
40 words
The combination of claims 33 or 34 wherein said antenna has a gain in the order of 35 dB or less (at 6 GHz) and said spreading code has a length in the order of a thousand or more elements.
References Cited (Backward Citations)
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