Techniques for non-geostationary satellite communication systems

Abstract

A satellite in a communications system may be equipped with an antenna system including various configurations of antenna arrays on one or more sides of the satellite for receiving and transmitting signals, and a transponder system coupled to such antenna arrays configured to route signals between one or more receiving ports and one or more transmitting ports. Such antenna arrays may be configured to support directional receiving, directional transmitting, or both, and the transponder system may perform one or more modes of signal processing. The satellite may be configured with specific combinations of components in the receiving and transmitting systems, and the corresponding transponder system may include various signal paths that support combinations of coupling between output ports and input ports and associated signal processing to support various techniques for relaying communications through the satellite.

Claims

1. It is a satellite, A receiving antenna system (305), A plurality of receiving antenna elements, each receiving antenna element having a first output port associated with a first polarization and a second output port associated with a second polarization orthogonal to the first polarization, A first receive beamforming network (320) coupled to the respective first output ports of the plurality of receiving antenna elements, wherein the first receive beamforming network (320) has a single output (322) configured to output a forward link uplink beam signal (132) that is at least partially based on a plurality of first forward link component signals received from the respective first output ports, A receiving antenna system (305) comprising: a second receiving beamforming network (320) coupled to the respective second output ports of the plurality of receiving antenna elements, wherein the second receiving beamforming network (320) has a single output (322) configured to output a return link uplink beam signal (173) that is at least partially based on a plurality of first return link component signals received from the respective second output ports; A single forward-link transponder (405) is configured to couple with the single output of the first receiving beamforming network and to output a forward-link downlink beam signal (172) that is at least partially based on the forward-link uplink beam signal, A single return link transponder (405) is configured to couple with the single output of the second receiving beamforming network and to output a return link downlink beam signal (133) that is at least partially based on the return link uplink beam signal, A transmitting antenna system (315), A plurality of transmitting antenna elements, each transmitting antenna element comprising a first input port associated with the first polarization and a second input port associated with the second polarization, A first transmit beamforming network (340) having a single input (342) operable to receive the forward-link downlink beam signal from the single forward-link transponder, wherein the first transmit beamforming network (340) is coupled to the respective first input ports of the plurality of transmit antenna elements and configured to output to the respective first input ports a respective second forward-link component signal that is at least partially based on the forward-link downlink beam signal, A satellite comprising a transmitting antenna system (315), the second transmitting beamforming network (340) having a single input (342) operable to receive the return link downlink beam signal from the single return link transponder, wherein the second transmitting beamforming network (340) is coupled to the respective second input ports of the plurality of transmitting antenna elements and configured to output to the respective second input ports each second return link component signal at least partially based on the return link downlink beam signal.

2. The plurality of receiving antenna elements are configured for reception in a first frequency range. The satellite according to claim 1, wherein the plurality of transmitting antenna elements are configured for transmission in a second frequency range that does not overlap with the first frequency range.

3. The single forward-link transponder includes a first frequency conversion circuit (325, 335) that supports generating the forward-link downlink beam signal according to a second frequency range, at least partially based on receiving the forward-link uplink beam signal according to a first frequency range, The satellite according to claim 2, comprising a second frequency conversion circuit (325, 335) that supports the single return link transponder generating the return link down link beam signal according to a second frequency range, at least in part, based on receiving the return link up link beam signal according to a first frequency range.

4. The satellite according to claim 2 or 3, further comprising a second receiving antenna system (282, 284) configured to receive control signaling in a third frequency range that does not overlap with the first frequency range and does not overlap with the second frequency range.

5. The plurality of receiving antenna elements of the receiving antenna system are located on the first side (215) of the satellite, The satellite according to claim 4, wherein the receiving element of the second receiving antenna system is located on the second side (211) of the satellite opposite to the first side.

6. The satellite according to any one of claims 2 to 5, further comprising a second transmitting antenna system (282, 284) configured to transmit control signaling in a third frequency range that does not overlap with the first frequency range and does not overlap with the second frequency range.

7. The plurality of transmitting antenna elements of the transmitting antenna system are located on the first side (215) of the satellite, The satellite according to claim 6, wherein the transmitting element of the second transmitting antenna system is located on the second side (211) of the satellite opposite to the first side.

8. The satellite according to any one of claims 2 to 7, wherein the extent of the first frequency range is equal to the extent of the second frequency range.

9. The satellite according to any one of claims 1 to 8, wherein the plurality of receiving antenna elements and the plurality of transmitting antenna elements are located on the same side (215) of the satellite body.

10. The single forward link transponder is configured with a first gain, The satellite according to any one of claims 1 to 9, wherein the single return link transponder is configured with a second gain greater than the first gain.

11. The first receive beamforming network, the second transmit beamforming network, or both are configured according to a first scan angle range. The satellite according to any one of claims 1 to 10, wherein the second receiving beamforming network, the first transmitting beamforming network, or both are configured according to a second scan angle range that is larger than the first scan angle range.

12. The first receiving beamforming network is configured to generate the forward link uplink beam signal, at least in part, by applying one or more first receiving beam weights to the plurality of first forward link component signals according to a first receiving direction with respect to the boresite of the receiving antenna system. The satellite according to any one of claims 1 to 11, wherein the second receiving beamforming network is configured to generate the return link uplink beam signal, at least in part on the basis of applying one or more second receiving beam weights to the plurality of first return link component signals according to a second receiving direction with respect to the boresite of the receiving antenna system.

13. In order to apply the one or more first received beam weights to the plurality of first forward link component signals, the first received beamforming network is configured to apply the respective phase adjustments to one or more of the plurality of first forward link component signals. The satellite according to claim 12, wherein the second receive beamforming network is configured to apply the one or more second receive beam weights to the plurality of first return link component signals, each of which is a second phase adjustment.

14. The first transmit beamforming network is configured to generate the respective second forward-link component signals, at least in part, by applying the respective first transmit beam weights to the forward-link and down-link beam signals according to a first transmit direction relative to the bore light of the transmit antenna system. The satellite according to any one of claims 1 to 13, wherein the second transmit beamforming network is configured to generate the respective second return link component signals, at least in part, based on applying the respective second transmit beam weights to the return link downlink beam signals according to a second transmit direction to the borelight of the transmit antenna system.

15. In order to apply the respective transmit beam weights to the forward-link downlink beam signals, the first transmit beamforming network is configured to apply the respective first phase adjustments to the forward-link downlink beam signals in order to generate one or more of the second forward-link component signals. The satellite according to claim 14, wherein the second transmit beamforming network is configured to apply the respective second phase adjustments to the return link downlink beam signals in order to apply the respective transmit beam weights to the return link downlink beam signals, in order to generate one or more of the second return link component signals.

16. The satellite according to any one of claims 1 to 15, further comprising one or more angular momentum systems capable of oriented the satellite to a coverage area serviced by the receiving antenna system, or the transmitting antenna system, or both.

17. In order to support communication in the coverage area via the gateway terminal 130, the satellite, The boresite (245) of the receiving antenna system, the boresite (255) of the transmitting antenna system, or both, are oriented to a location in the coverage area that is within a first range of angular separation from the first direction of the gateway terminal. The satellite according to any one of claims 1 to 16, configured to support communication with one or more user terminals each located along a second direction within a second range of angular separation from the boresite of the receiving antenna system, the boresite of the transmitting antenna system, or both, wherein the second range of angular separation is greater than the first range of angular separation.

18. The satellite according to claim 17, wherein the second range of angle separation is at least two times larger than the first range of angle separation.

19. A satellite according to any one of claims 1 to 18, configured for operation in a non-geostationary orbit.

20. It is a system for satellite communications, Multiple gateway terminals (130), Multiple user terminals (150) and The system comprises a plurality of satellites (120) configured to provide communication services between the plurality of gateway terminals and the plurality of user terminals, and each satellite is Receiving antenna system (3050, A plurality of receiving antenna elements, each receiving antenna element having a first output port associated with a first polarization and a second output port associated with a second polarization orthogonal to the first polarization, A first receive beamforming network (320) coupled to the respective first output ports of the plurality of receiving antenna elements, wherein the first receive beamforming network (320) has a single output (322) configured to output a forward link uplink beam signal (132) that is at least partially based on a plurality of first forward link component signals received from the respective first output ports, A receiving antenna system (3050) comprising: a second receiving beamforming network (320) coupled to the second output ports of each of the plurality of receiving antenna elements, wherein the second receiving beamforming network (320) has a single output (322) configured to output a return link uplink beam signal (173) that is at least partially based on a plurality of first return link component signals received from each of the second output ports; A single forward-link transponder (405) is configured to couple with the single output of the first receiving beamforming network and to output a forward-link downlink beam signal (172) that is at least partially based on the forward-link uplink beam signal, A single return link transponder (405) is configured to couple with the single output of the second receiving beamforming network and to output a return link downlink beam signal (133) that is at least partially based on the return link uplink beam signal, A transmitting antenna system (315), A plurality of transmitting antenna elements, each transmitting antenna element comprising a first input port associated with the first polarization and a second input port associated with the second polarization, A first transmit beamforming network (340) having a single input (342) operable to receive the forward-link downlink beam signal from the single forward-link transponder, wherein the first transmit beamforming network (340) is coupled to the respective first input ports of the plurality of transmit antenna elements and configured to output to the respective first input ports a respective second forward-link component signal that is at least partially based on the forward-link downlink beam signal, A transmitting antenna system (315) comprising: a second transmit beamforming network having a single input operable to receive the return link downlink beam signal from the single return link transponder, wherein the second transmit beamforming network is coupled to the respective second input ports of the plurality of transmit antenna elements and configured to output to the respective second input ports each second return link component signal based at least partially on the return link downlink beam signal.

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