Satellite system with single polarization path

• US 10,594,046 B2
• Filed: 06/03/2016
• Issued: 03/17/2020
• Est. Priority Date: 03/29/2016
• Status: Active Grant

• Current Assignee: Maxar Space LLC (Galileo Parent, Inc.)
• Original Assignee: Space Systems/Loral Incorporated (Loral Space and Communications Incorporated)
• Inventors: Hreha, William, Lamontagne, Guillaume, Hildebrand, Louis Trichardt
• Primary Examiner(s): Heiber, Shantell L
• Application Number:
  US15/172,965
• Publication Number:
  US 20180006382A1
• Time in Patent Office: 1,383 Days
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 3/2682 Time delay steered arrays
• CPC Class Codes: H04B 7/043 using best eigenmode, e.g. beam forming or beam steering
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/18519 Operations control, administration or maintenance
• CPC Class Codes: H04B 7/18521 Systems of inter linked satellites, i.e. inter satellite service for optical links between satellites H04B10/118
• CPC Class Codes: H04B 7/18523 Satellite systems for providing broadcast service to terrestrial stations, i.e. broadcast satellite service arrangements specially adapted for satellite broadcast receiving H04H40/90; picture transmission via satellite H04N1/00103; television transmission via satellite H04N7/20
• CPC Class Codes: H04B 7/18534 for enhancing link reliablility, e.g. satellites diversity
• CPC Class Codes: H04B 7/18541 for handover of resources
• CPC Class Codes: H04B 7/18547 for geolocalisation of a station position fixing by direction or distance determination G01S5/00
• CPC Class Codes: H04B 7/18578 Satellite systems for providing broadband data service to individual earth stations for selecting H04W; provisions for broadband connection, H04Q11/0478
• CPC Class Codes: H04B 7/18584 Arrangements for data networking, i.e. for data packet routing, for congestion control data switching networks H04L12/00
• CPC Class Codes: H04B 7/18595 Arrangements for adapting broadband applications to satellite systems
• CPC Class Codes: H04B 7/19 Earth-synchronous stations
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams
• CPC Class Codes: H04W 72/21 : in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 : in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 84/18 : Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A satellite communication system comprises one or more non-geostationary satellites. Each satellite is configured to provide a plurality of spot beams. The polarizations of the spot beams are laid out on each satellite so that terminals have a constant polarization as the field of regard traverses the terminal location.

Claims

1. A satellite communication system, comprising:

a non-geostationary satellite configured to provide a plurality of spot beams that use multiple frequencies and multiple polarities for a direction of communication, each spot beam of the plurality of spot beams forms a respective coverage area on Earth'"'"'s surface such that a plurality of coverage areas in aggregate comprise a beam map, the satellite is configured such that as the satellite moves in orbit around the Earth the beam map drifts across the Earth'"'"'s surface and causes a location on the Earth to progress through coverage areas along a path across the beam map from a first end of the beam map to a second end of the beam map, all coverage areas along the path across the beam map are formed by spot beams that use a first polarization for the direction of communication, other spot beams of the plurality of spot beams that form coverage areas off of the path use a second polarization for the direction of communication, adjacent coverage areas along the path are formed by spot beams that use the first polarization for the direction of communication but different frequency ranges for the direction of communication.

2. A satellite communication system according to claim 1, further comprising:

additional satellites that together with the non-geostationary satellite form a constellation of non-geostationary satellites that each are configured to provide a plurality of spot beams that use multiple frequencies and multiple polarities; and

each satellite of the constellation has a same beam map.

3. A satellite communication system according to claim 2, wherein:

polarizations are assigned to the spot beams of the satellites of the constellation such that all spot beams of all satellites of the constellation that illuminate and are configured to communicate with the location on the Earth use the first polarization for the direction of communication.

4. A satellite communication system according to claim 2, wherein:

each satellite of the constellation hands over communication with a terminal between adjacent spot beams of the same satellite that use the first polarization for the direction of communication when the terminal is within the beam map for the respective satellite; and

each satellite of the constellation hands over communication with the terminal to a spot beam of a different satellite that uses the first polarization for the direction of communication when the terminal is near an edge of the beam map for the respective satellite.

5. A satellite communication system according to claim 1, wherein:

the coverage areas along the path across the beam map include a first coverage area formed by a first spot beam of the plurality of spot beams and a second coverage area formed by a second spot beam of the plurality of spot beams, the first coverage area is adjacent the second coverage area;

the satellite is configured to communicate with a terminal within the first coverage area via the first spot beam using the first polarization;

the satellite is configured to hand over communication with the terminal from the first spot beam to the second spot beam when the beam map drifts such that the first terminal is near the edge of the first coverage area; and

the satellite is configured to communicate with the terminal via the second spot beam using the first polarization after the hand over of communication with the terminal from the first spot beam to the second spot beam.

6. A satellite communication system according to claim 1, wherein:

the plurality of spot beams are fixed in direction relative to the satellite.

7. A satellite communication system according to claim 1, wherein:

the plurality of spot beams implement a multiple color reuse plan.

8. A satellite communication system according to claim 1, wherein:

the plurality of spot beams comprise multiple beam hopping groups that implement a beam hopping plan.

9. A satellite communication system, comprising:

a non-geostationary satellite configured to provide a plurality of spot beams that use multiple frequencies and multiple polarities, each spot beam of the plurality of spot beams is configured to communicate in at least one frequency range and polarity, the plurality of spot beams are configured to provide coverage areas on Earth that the satellite can communicate with based on the satellite'"'"'s position, as the satellite moves in orbit with respect to the Earth the coverage areas move over the Earth'"'"'s surface such that over time different spot beams of the plurality of spot beams will have coverage areas move over a ground terminal and then move away from the ground terminal, the satellite is configured to communicate with the ground terminal as the coverage areas move over the ground terminal by communicating with the ground terminal using the different spot beams such that communication is performed using whichever spot beam of the different spot beams has its coverage area currently over the ground terminal, the different spot beams have a same polarity, the different spot beams comprise all spot beams of the satellite that communicate with the ground terminal, the satellite is configured such that adjacent spot beams of the different spot beams use different frequency ranges for communication with the ground terminal, the spot beams of the different spot beams form a plurality of continuous overlapping coverage areas on the Earth'"'"'s surface when the satellite is in orbit over the Earth.

10. A satellite communication system according to claim 9, further comprising:

additional satellites that together with the non-geostationary satellite form a constellation of non-geostationary satellites that each are configured to provide a plurality of spot beams that use multiple frequencies and multiple polarities; and

for each satellite of the constellation, polarizations are assigned to the spot beams such that all spot beams that illuminate and are configured to communicate with the ground terminal use a same polarity.

11. A satellite communication system according to claim 10 wherein:

each satellite of the constellation has a same beam map.

12. A satellite communication system according to claim 10 wherein:

each satellite dynamically interconnects the spot beams using an onboard digital channelizer.

13. A satellite communication system according to claim 9, wherein:

the plurality of spot beams are fixed in direction relative to the satellite; and

the satellite further comprises additional steerable beams.

14. A satellite communication system, comprising:

a non-geostationary satellite configured to provide a plurality of non-articulated spot beams that use multiple frequencies and multiple polarities, all non-articulated spot beams of the satellite form a Field of Regard for the satellite, each non-articulated spot beam of the plurality of non-articulated spot beams is configured to communicate in at least one frequency range and polarity, the satellite is configured to communicate with a ground location using a common polarization and different frequencies across the entire Field of Regard as the satellite moves in orbit and different spot beams across the entire Field of Regard are used to communicate with the ground location, two adjacent spot beams of the different spot beams across the entire Field of Regard that are used to communicate with the ground location use different frequency ranges and the common polarization, other spot beams of the plurality of non-articulated spot beams outside of the different spot beams across the entire Field of Regard that are used to communicate with the ground location use a polarization that is different than the common polarization.

15. A satellite communication system according to claim 14, further comprising:

additional satellites that together with the non-geostationary satellite form a constellation of non-geostationary satellites that each are configured to provide a plurality of spot beams that use multiple frequencies and multiple polarities; and

each satellite of the constellation is configured to communicate with a location always using a common polarization as the satellites move and different spot beams are used to communicate with the location.

16. A satellite communication system, comprising:

a constellation of non-geostationary satellites, each satellite of the constellation is configured to travel along a same orbital path, each satellite is configured to provide a plurality of non-articulated spot beams, each non-articulated spot beam forms a respective coverage area on Earth'"'"'s surface such that all coverage areas for a same satellite in aggregate comprise a beam map, beam maps of adjacent satellites overlap and the satellites are configured to provide the non-articulated spot beams so that continuous connectivity is provided between a terminal and the constellation of satellites, polarizations of the spot beams being laid out on each satellite so that the terminal has a constant polarization as the terminal hands over between non-articulated spot beams of a same satellite and between non-articulated spot beams of different satellites of the constellation during the continuous connectivity.