Satellite for end-to-end beamforming with access node clusters

Patent metadata

Field	Value
Publication number	US-10079636-B2
Application number	US-201715719186-A
Country	US
Kind code	B2
Filing date	Sep 28, 2017
Priority date	Apr 10, 2015
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

Methods and systems are described for providing end-to-end beamforming. For example, end-to-end beamforming systems include end-to-end relays and ground networks to provide communications to user terminals located in user beam coverage areas. The ground segment can include geographically distributed access nodes and a central processing system. Return uplink signals, transmitted from the user terminals, have multipath induced by a plurality of receive/transmit signal paths in the end to end relay and are relayed to the ground network. The ground network, using beamformers, recovers user data streams transmitted by the user terminals from return downlink signals. The ground network, using beamformers generates forward uplink signals from appropriately weighted combinations of user data streams that, after relay by the end-end-end relay, produce forward downlink signals that combine to form user beams.

First claim

What is claimed is:

1. A satellite for providing communications between a plurality of access node clusters and a plurality of user terminals, wherein each access node cluster of the plurality of access node clusters comprises a plurality of access nodes geographically distributed within a corresponding access node area, and wherein the plurality of user terminals are geographically distributed over a user coverage area, the satellite comprising:
a feeder-link antenna subsystem comprising a feeder-link element array to illuminate the plurality of access node clusters, the feeder-link element array comprising an array of cooperating feeder-link constituent transmit elements and an array of cooperating feeder-link constituent receive elements;
a user-link antenna subsystem comprising a user-link element array to illuminate the user coverage area, the user-link element array comprising an array of cooperating user-link constituent transmit elements and an array of cooperating user-link constituent receive elements;
a plurality of forward-link transponders, each coupled between a respective one of the feeder-link constituent receive elements and a respective one of the user-link constituent transmit elements; and
a plurality of return-link transponders, each coupled between a respective one of the user-link constituent receive elements and a respective one of the feeder-link constituent transmit elements.

2. The satellite of claim 1 , wherein the feeder-link element array comprises a first set of feeder-link elements illuminating a first one of the plurality of access node clusters and a second set of feeder-link elements illuminating a second one of the plurality of access node clusters.

3. The satellite of claim 2 , wherein inputs of a first subset of the plurality of forward-link transponders are coupled with respective feeder-link constituent receive elements of the first set of feeder-link elements and inputs of a second subset of the plurality of forward-link transponders are coupled with respective feeder-link constituent receive elements of the second set of feeder-link elements.

4. The satellite of claim 3 , wherein outputs of the first subset of the plurality of forward-link transponders are coupled with user-link constituent transmit elements of a first set of user-link elements and outputs of the second subset of the plurality of forward-link transponders are coupled with user-link constituent transmit elements of a second set of user-link elements.

5. The satellite of claim 3 , wherein the first set of feeder-link elements illuminates the first one of the plurality of access node clusters over a first frequency range, and the second set of feeder-link elements illuminates the second one of the plurality of access node clusters over a second frequency range, wherein the second frequency range is non-overlapping with the first frequency range.

6. The satellite of claim 5 , wherein:
the first subset of the plurality of forward-link transponders comprise first forward frequency converters that convert first forward input signals over the first frequency range to first output signals at a third frequency range; and
the second subset of the plurality of forward-link transponders comprise second forward frequency converters that convert second input signals over the second frequency range to second output signals over the third frequency range.

7. The satellite of claim 6 , wherein inputs of a first subset of the plurality of return-link transponders are coupled with respective user-link constituent receive elements of the first set of user-link elements and inputs of a second subset of the plurality of return-link transponders are coupled with respective user-link constituent receive elements of the second set of user-link elements.

8. The satellite of claim 7 , wherein:
the first subset of the plurality of return-link transponders comprise first return frequency converters that convert first return input signals over the third frequency range to first return output signals over the first frequency range; and
the second subset of the plurality of return-link transponders comprise second return frequency converters that convert second return input signals over the third frequency range to second return output signals over the second frequency range.

9. The satellite of claim 2 , wherein the plurality of forward-link transponders comprise respective forward-link receive element switches that selectively couple inputs of the plurality of forward-link transponders to respective cooperating feeder-link constituent receive elements of either the first set of feeder-link elements or the second set of feeder-link elements.

10. The satellite of claim 1 , wherein:
the user-link element array comprises a first user-link element array illuminating a first portion of the user coverage area and a second user-link element array illuminating a second portion of the user coverage area; and
the plurality of forward-link transponders comprise respective forward-link transmit element switches that selectively couple outputs of the plurality of forward-link transponders to respective cooperating user-link constituent transmit elements of either the first user-link element array or the second user-link element array.

11. The satellite of claim 10 , wherein the corresponding access node area of the first one of the plurality of access node clusters is non-overlapping with the second portion of the user coverage area and the corresponding access node area of the second one of the plurality of access node clusters is non-overlapping with the first portion of the user coverage area.

12. The satellite of claim 2 , wherein the plurality of return link transponders comprise respective return-link transmit element switches that selectively couple outputs of the plurality of return link transponders to respective cooperating feeder-link constituent transmit elements of either the first feeder-link element array or the second feeder-link element array.

13. The satellite of claim 12 , wherein:
the user-link element array comprises a first user-link element array illuminating a first portion of the user coverage area and a second user-link element array illuminating a second portion of the user coverage area; and
the plurality of return-link transponders comprise respective return-link receive element switches that selectively couple inputs of the plurality of return-link transponders to respective cooperating user-link constituent receive elements of either the first user-link element array or the second user-link element array.

14. The satellite of claim 2 , wherein:
the feeder-link antenna subsystem comprises a single reflector; and
the first set of feeder-link elements illuminates the first one of the plurality of access node clusters via the single reflector and the second set of feeder-link elements illuminates the second one of the plurality of access node clusters via the single reflector.

15. The satellite of claim 14 , wherein the first set of feeder-link elements and the second set of feeder-link elements are disposed within a single feeder-link element array.

16. The satellite of claim 2 , wherein the first set of feeder-link elements illuminates the first one of the plurality of access node clusters via a first reflector and the second set of feeder-link elements illuminates the second one of the plurality of access node clusters via a second reflector.

17. A method for providing a communication service to user terminals geographically distributed over a user coverage area via an end-to-end

Assignees

• Viasat Inc

Inventors

• Buer Kenneth V
• Miller Mark J
• Cronin Christopher J
• Dankberg Mark D
• Runyon Donald L

Classifications

• H04W4/00

  Services specially adapted for wireless communication networks; Facilities therefor · CPC title

• H04B7/024

  Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems · CPC title

• H04B7/0413

  MIMO systems · CPC title

• H01Q1/06

  Means for the lighting or illuminating of antennas, e.g. for purpose of warning · CPC title

• H04B7/18508

  with satellite system used as relay, i.e. aeronautical mobile satellite service · CPC title