EP0311919A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Satellite communications system employing frequency reuse
Assignee: Raytheon Co
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Filing: 1988-10-07
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Granted: —
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Expires: 2008-10-07
Abstract
Abstract A satellite communications system employs separate subsystems for broadcast and point-to-point two-way communcations using the same assigned frequency band and employs an antenna system which uses a common reflector (12). The point-to-point subsystem achieves increased communication capacity through the reuse of the assigned frequency band over multiple, contiguous zones (32, 34, 36, 38) covering the area of the earth to be serviced. Small aperture terminals in the zones are serviced by a plurality of high-gain downlink fan beams (29) steered in the east-west direction by frequency address. A special beam-forming network (98) provides in conjunction with an array antenna (20) the multiple zone frequency address function. The satellite (10) employs a filter interconnection matrix (90) for connecting earth terminals in different zones to permit multiple reuse of the entire band of assigned frequencies. A single pool of solid-state transmitters allows rain-disadvantaged users to be assigned higher than normal power at minimum cost and geographically disperses the transmitter intermodulation products. In an alternate embodiment, the satellite (200) employs direct radiating array antennas (202, 204) for reception and transmission. The system (200) utilizes hybrid-coupled dual amplifiers (251) to reduce amplifier production costs. In another embodiment, both point-to-point and broadcast services are available on a single polarization by allocating one-half of the frequency spectrum to each service and by using separate direct radiating arrays from horizontal and vertical polarization for both reception (235, 236) and transmission (237, 238). The frequency spectrum is reused in each of the contiguous receive zones (220, 222, 224, 226) and the transmit zones (228, 230, 232, 234) because sufficient spatial isolation is achieved by subdividing the receive zones in two halves (220a, 220b, 222a, 222b, 224a, 224b, 226a, 226b), and by using one-half of the frequency spectrum in each subdivided zone.
Inventors
- 👤 Harold A. Rosen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 10:58
CPC Classifications
H; H01; H01Q; H01Q25/00; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/185; H04B7/1851; H04B7/18515; H04B7/204; H04B7/2041; H04B7/2045; Y; Y02; Y02D; Y02D30/00; Y02D30/70
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
215 words
A method of communicatively interconnecting any of a plurality of terminals within an area on the earth using an earth-orbiting communications satellite (10; 200; 250), comprising the steps of: A) forming a first plurality of groups of radio frequency beams (221, 223, 225, 227, 229, 231, 233, 240), respectively, between each of a plurality of zones (220A, 220B, 222A, 222B, 224A, 224B, 226A, 226B) covering said area on the earth and said satellite (10; 200; 250) the beams (221, 223, 225, 227, 229, 231, 233, 240) in groups thereof carrying communication signals over the same first preselected range of frequencies, such that said first preselected range of frequencies is reused by the beams (221, 223, 225, 227, 229, 231, 233, 240) for all of said zones (220A, 220B, 222A, 222B, 224A, 224B, 226A, 226B); B) separating each group of said radio frequency beams (221, 223, 225, 227, 229, 231, 233, 240) into first (221/225/229/233) and second (223/227/231/240) sets thereof, respectively, carrying communication signals over first and second sets of frequencies within said first preselected range of frequencies; C) alternately transmitting said first (221/225/229/233) and second (223/227/231/240) sets of said beams (221, 223, 225, 227, 229, 231, 233, 240) between said zones (220A, 220B, 222A, 222B, 224A, 224B, 226A, 226B) and said satellite (10; 200; 250).
Claim 2
Independent Claim
215 words
A method of communicatively interconnecting any of a plurality of terminals within an area on the earth using an earth-orbiting communications satellite (10; 200; 250), comprising the steps of: A) forming a first plurality of groups of radio frequency beams (221, 223, 225, 227, 229, 231, 233, 240), respectively, between each of a plurality of zones (220A, 220B, 222A, 222B, 224A, 224B, 226A, 226B) covering said area on the earth and said satellite (10; 200; 250) the beams (221, 223, 225, 227, 229, 231, 233, 240) in groups thereof carrying communication signals over the same first preselected range of frequencies, such that said first preselected range of frequencies is reused by the beams (221, 223, 225, 227, 229, 231, 233, 240) for all of said zones (220A, 220B, 222A, 222B, 224A, 224B, 226A, 226B); B) separating each group of said radio frequency beams (221, 223, 225, 227, 229, 231, 233, 240) into first (221/225/229/233) and second (223/227/231/240) sets thereof, respectively, carrying communication signals over first and second sets of frequencies within said first preselected range of frequencies; C) alternately transmitting said first (221/225/229/233) and second (223/227/231/240) sets of said beams (221, 223, 225, 227, 229, 231, 233, 240) between said zones (220A, 220B, 222A, 222B, 224A, 224B, 226A, 226B) and said satellite (10; 200; 250).
Claim 3
Dependent Claim
103 words
The method of claim 1, wherein step (B) is performed by spatially distributing the first preselected range of said frequencies over each zone (220A, 220B, 222A, 222B, 224A, 224B, 226A, 226B) such that contiguous sections of the area serviced by the beams (221, 223, 225, 227, 229, 231, 233, 240) in adjacent zones (220A/220B, 222A/222B, 224A/224B, 226A/226B) are respectively covered by different sets (221/225/229/233, 223/227/231/240) of said beams (221, 223, 225, 227, 229, 231, 233, 240) to avoid communication interference in the areas serviced by the beams (221, 223, 225, 227, 229, 231, 233, 240) in said adjacent zones (220A/220B, 222A/222B, 224A/224B, 226A/226B).
Claim 4
Independent Claim
69 words
The method of any of claims 1 or 2, wherein step (C) is performed by simultaneously transmitting the beams (221, 223, 225, 227, 229, 231, 233, 240) in the first set (221/225/229/233) thereof for all the zones (220, 222, 224, 226) and then simultaneously transmitting the beams (221, 223, 225, 227, 229, 231, 233, 240) in the second set (223/227/231/240) thereof for all the zones (220, 222, 224, 226).
Claim 5
Independent Claim
47 words
The method of any of claims 1 or 2, wherein step (C) is performed by transmitting the first (222/225/229/233) and second (223/227/231/240) of beams (221, 223, 225, 227, 229, 231, 233, 240) from each of said zones (220, 222, 224, 226) to said satellite (10; 200; 250).
Claim 6
Independent Claim
109 words
The method of any of the claims 1 through 3, characterized by the further steps of: D) receiving said first (221/225/229/233) and second (223/227/231/240) sets of beams (221, 223, 225, 227, 229, 231, 233, 240) at said satellite (10; 200; 250); and E) transmitting a second plurality of groups of radio frequency beams, respectively, from said satellite (10; 200; 250) to said zones (220, 222, 224, 226), the beams in each group of said second plurality thereof carrying communication signals over the same second preselected range of frequencies, whereby said second preselected range of frequencies is reused by all of the groups of beams in said second plurality thereof.
Claim 7
Dependent Claim
38 words
The method of claim 5, wherein step (E) is performed by spatially distributing the beams in each of said second plurality of groups thereof across the corresponding zone as a function of said second preselected range of frequencies.
Claim 8
Independent Claim
184 words
A method of communicatively interconnecting a plurality of terminals within an area on the earth using an earth-orbiting communications satellite (10; 200; 250), comprising the steps of: A) dividing said area into a plurality of essentially contiguous zones (220, 222, 226); B) dividing each zone (220, 222, 224, 226) into at least first (220A, 222A, 224A, 226A) and second (220B, 222B, 224B, 226B) sections; C) alternately transmitting at least first (221/225/229/233) and second (223/227/231/240) radio frequency beams (221, 223, 225, 227, 229, 231, 233, 240), respectively, between said first (220A, 222A, 224A, 226A) and second (220B, 222B, 224B, 226B) sections for each of said zones (220, 222, 224, 226) and said satellite (10; 200; 250), said first (221/225/229/233) and second (223/227/231/240) beams (221, 223, 225, 227, 229, 231, 235, 240), respectively, carrying communication signals over first and second different sets of frequencies defining a first preselected range of frequencies, wherein said first preselected range of frequencies is reused by the first (221/225/229/233) and second (223, 227/231/240) beams (221, 223, 225, 227, 229, 231, 233, 240) for all of said zones (220, 222, 224, 226).
Claim 9
Independent Claim
184 words
A method of communicatively interconnecting a plurality of terminals within an area on the earth using an earth-orbiting communications satellite (10; 200; 250), comprising the steps of: A) dividing said area into a plurality of essentially contiguous zones (220, 222, 226); B) dividing each zone (220, 222, 224, 226) into at least first (220A, 222A, 224A, 226A) and second (220B, 222B, 224B, 226B) sections; C) alternately transmitting at least first (221/225/229/233) and second (223/227/231/240) radio frequency beams (221, 223, 225, 227, 229, 231, 233, 240), respectively, between said first (220A, 222A, 224A, 226A) and second (220B, 222B, 224B, 226B) sections for each of said zones (220, 222, 224, 226) and said satellite (10; 200; 250), said first (221/225/229/233) and second (223/227/231/240) beams (221, 223, 225, 227, 229, 231, 235, 240), respectively, carrying communication signals over first and second different sets of frequencies defining a first preselected range of frequencies, wherein said first preselected range of frequencies is reused by the first (221/225/229/233) and second (223, 227/231/240) beams (221, 223, 225, 227, 229, 231, 233, 240) for all of said zones (220, 222, 224, 226).
Claim 10
Dependent Claim
76 words
The method of claim 7, characterized by including the step of forming said first (221/225/229/233) and second (223/227/231/240) beams (221, 223, 225, 227, 229, 231, 233, 240) for each of said zones (220, 222, 224, 226) such that said first (221/225/229/233) and second (223/227/231/240) beam for each of said zones (220, 222, 224, 226) collectively define a rectangularly shaped area of communications service on the earth which corresponds to the associated zone (220, 222, 224, 226).
Claim 11
Dependent Claim
17 words
The method of claim 8, characterized by said rectangularly shaped areas of communications service being essentially contiguous.
Claim 12
Independent Claim
67 words
The method of any of claims 7 through 9, characterized by at least two of said sections (220A/220B, 222A/222B, 224A/224B, 226A/226B) of respective contiguous zones (220, 222, 224, 226) being contiguous to each other and said sets of frequencies of said contiguous two sections (220A/220B, 222A/222B, 224A/224B, 226A/226B) being different from each other, whereby to avoid communications interference between said contiguous two sections (220A/220B, 222A/222B, 224A/224B, 226A/226B).
Claim 13
Independent Claim
95 words
The method of any of claims 7 through 10, characterized by the further steps of: D) receiving said first (221/225/229/233) and second (223/227/231/240) beams (221, 223, 225, 227, 229, 231, 233, 240) at said satellite (10; 200; 250); and E) transmitting to each of said zones (220, 222, 224, 226) a plurality of downlink radio beams, each plurality of said downlink beams carrying communication signals over the same, second preselected range of frequencies, whereby said second preselected range of frequencies is reused by the downlink beams for all of said zones (220, 222, 224, 226).
Claim 14
Dependent Claim
27 words
The method of claim 11, characterized by step (E) including the step of spatially disbursing the downlink beams in each plurality thereof as a function of frequency.
Claim 15
Independent Claim
65 words
A method of communicatively interconnecting a plurality of terminals within an area on the earth using an earth-orbiting communications satellite (10; 200; 250), characterized by the step of establishing an uplink communication from a first terminal to said satellite (10; 200; 250) and a downlink communication from said satellite (10; 200; 250) to a second terminal, said communication being made on a predetermined frequency band.
Claim 16
Independent Claim
65 words
A method of communicatively interconnecting a plurality of terminals within an area on the earth using an earth-orbiting communications satellite (10; 200; 250), characterized by the step of establishing an uplink communication from a first terminal to said satellite (10; 200; 250) and a downlink communication from said satellite (10; 200; 250) to a second terminal, said communication being made on a predetermined frequency band.
Claim 17
Dependent Claim
319 words
A satellite communications system for communicatively interconnecting a plurality of earth terminals covering an area on the earth, characterized by: a satellite (10; 200; 250) disposed in orbit above the earth; first means for forming a plurality of uplink radio frequency beams (221, 223, 225, 227, 229, 231, 233, 240) between said satellite (10; 200; 250) and each of a plurality of respectively associated zones (220, 222, 224, 226) covering said area, said zones (220, 222, 224, 226) being divided into at least two sections (220A/220B, 222A/222B, 224A/224B, 226A/226B), each plurality of said uplink beams (221, 223, 225, 227, 229, 231, 233, 240) carrying communication signals destined to be received by downlink terminal sites in said zones (220, 222, 224, 226), the uplink beams (221, 223, 225, 227, 229, 231, 233, 240) for each zone (220, 222, 224, 226) being arranged in first (221/225/229/233) and second (223/227/231/240) sets of said beams (221, 223, 225, 227, 229, 231, 233, 240), respectively, originating from said two sections (220A/220B, 222A/222B, 224A/224B, 226A/226B) in the zone (220, 222, 224, 226) and carrying communication signals over first and second sets of frequencies, said first and second sets of frequencies defining a first range of frequencies, the uplink beams (221, 223, 225, 227, 229, 231, 233, 240) for all of said zones (220, 222, 224, 226) using said first range of frequencies; second means at said satellite (10; 200; 250) for alternately receiving said first (221/225/229/233) and second (223/227/231/240) sets of beams (221, 223, 225, 227, 229, 231, 233, 240); and third means at said satellite (10; 200; 250) coupled with said second means for forming a plurality of groups of downlink radio frequency beams between said satellite (10; 200; 250) and said zones (220, 222, 224, 226), each of said groups of downlink beams carrying communication signals destined to be received at downlink terminal sites in one of said zones (220, 222, 224, 226).
Claim 18
Dependent Claim
319 words
A satellite communications system for communicatively interconnecting a plurality of earth terminals covering an area on the earth, characterized by: a satellite (10; 200; 250) disposed in orbit above the earth; first means for forming a plurality of uplink radio frequency beams (221, 223, 225, 227, 229, 231, 233, 240) between said satellite (10; 200; 250) and each of a plurality of respectively associated zones (220, 222, 224, 226) covering said area, said zones (220, 222, 224, 226) being divided into at least two sections (220A/220B, 222A/222B, 224A/224B, 226A/226B), each plurality of said uplink beams (221, 223, 225, 227, 229, 231, 233, 240) carrying communication signals destined to be received by downlink terminal sites in said zones (220, 222, 224, 226), the uplink beams (221, 223, 225, 227, 229, 231, 233, 240) for each zone (220, 222, 224, 226) being arranged in first (221/225/229/233) and second (223/227/231/240) sets of said beams (221, 223, 225, 227, 229, 231, 233, 240), respectively, originating from said two sections (220A/220B, 222A/222B, 224A/224B, 226A/226B) in the zone (220, 222, 224, 226) and carrying communication signals over first and second sets of frequencies, said first and second sets of frequencies defining a first range of frequencies, the uplink beams (221, 223, 225, 227, 229, 231, 233, 240) for all of said zones (220, 222, 224, 226) using said first range of frequencies; second means at said satellite (10; 200; 250) for alternately receiving said first (221/225/229/233) and second (223/227/231/240) sets of beams (221, 223, 225, 227, 229, 231, 233, 240); and third means at said satellite (10; 200; 250) coupled with said second means for forming a plurality of groups of downlink radio frequency beams between said satellite (10; 200; 250) and said zones (220, 222, 224, 226), each of said groups of downlink beams carrying communication signals destined to be received at downlink terminal sites in one of said zones (220, 222, 224, 226).
Claim 19
Dependent Claim
53 words
The system of claim 14, characterized by each of said groups of downlink beams covering one of said zones (220, 222, 224, 226) with each group carrying a plurality of signals over a second range of frequencies such that the same range of frequencies are used by all the groups of downlink beams.
Claim 20
Independent Claim
46 words
The system of any of claims 14 or 15, characterized by said second means including a receiving antenna array (236), a receiver (269) and a two position switch (267) for successively switching said receiver (269) to alternately receive said first and second sets of frequencies, respectively.
Claim 21
Independent Claim
46 words
The system of any of claims 14 through 16, characterized by said third means including a transmitting antenna (238) for transmitting said downlink beams, said receiving antenna array (236) and said transmitting antenna array (238) each being defined by a two-dimensional array of direct radiating elements.
Claim 22
Dependent Claim
70 words
A satellite communications system for communicatively interconnecting a plurality of earth terminals covering an area on the earth, characterized by a satellite (10; 200; 250) disposed in orbit above the earth and means for establishing an uplink communication from a first terminal to said satellite (10; 200; 250) and a downlink communication from said satellite (10; 200; 250) to a second terminal, said means operating on a predetermined frequency band.
Claim 23
Dependent Claim
70 words
A satellite communications system for communicatively interconnecting a plurality of earth terminals covering an area on the earth, characterized by a satellite (10; 200; 250) disposed in orbit above the earth and means for establishing an uplink communication from a first terminal to said satellite (10; 200; 250) and a downlink communication from said satellite (10; 200; 250) to a second terminal, said means operating on a predetermined frequency band.
References Cited (Backward Citations)
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