Patent ID: 6954614
Filing Date: 2005-10-11
Classification: H04B,H04H

Abstract:
1. A communication spacecraft for providing cellular communications among a plurality of user terminals and ground stations, by way of paths having a bandwidth generally suited for audio signals, and for also providing communications among at least said ground stations by way of at least one path having a bandwidth at least five times greater than said bandwidth suitable for audio signals, said spacecraft comprising: a downlink antenna including a plurality of antenna elements, for receiving guided electromagnetic energy at each of said antenna elements, and for radiating said energy in the form of unguided radiation: an analog beamformer including a plurality of beam input ports and a plurality of elemental antenna ports, each of which is coupled to one of said antenna elements, for producing at least one independent beam of electromagnetic downlink radiation from guided energy applied to each of said beam input ports, so that plural downlink antenna beams are formed when signals are applied to a plurality of said beam input ports of said analog beamformer; receiving means for receiving unguided electromagnetic uplink radiation including at least one carrier, and for at least transducing said unguided electromagnetic uplink radiation into guided electromagnetic energy on a plurality of separate paths; a narrowband digital channelizer having individual channel bandwidths suitable for audio signals, said channelizer including a plurality of input ports and a plurality of output ports, at least some of said input ports of said digital channelizer being coupled by way of corresponding ones of said plurality of separate paths to said receiving means, for receiving said guided electromagnetic energy from a plurality of said separate paths, and for extracting each of said independent narrowband signals from said at least one carrier, to thereby produce separated independent narrowband signals on said plurality of output ports of said digital channelizer; a wideband channelizer having an individual channel bandwidth at least five times greater than that of an individual channel of said narrowband channelizer, said wideband channelizer being coupled to at least a portion of said receiving means, for extracting at least one wideband signal from said carrier, to thereby produce separated independent wideband signals; a switching arrangement coupled to said plurality of output ports of said narrowband channelizer and to said wideband channelizer, for receiving said independent narrowband signals and said wideband signals, and for grouping together those signals associated with each of said plural downlink antenna beams, to thereby produce combined signals grouped by beam, where said combined signals may include any number of said wideband signals, including the number zero; and a coupling arrangement coupled to said switching arrangement and to said beamformer, for coupling said combined signals grouped by beam to that one of said input ports of said beamformer associated with the beam of said group.