Satellite communications system and method therefor

Abstract

Abstract A satellite communications system and method of communication which results in increased frequency-reusage within assigned frequency bands and allows for a reduction in satellite transponder requirements per unit of bandwidth employed. The disclosed system employs a satellite in a geostationary orbit having transponders and one or more large-aperture, high-gain antennas that provide a broad-area beam for a relatively wide service area and for transmitting to and receiving signals from N narrow-area beams for N respective sub-areas, the sub-areas corresponding to the high-traffic nodes. Both beam types operate in the same allocated frequency bands but with opposite linear or opposite handed circular polarizations, or, alternatively, with arbitrarily determined portions of the allocated frequency band pairs with dual polarization so that the allocated frequency spectrum is used at least N+1 times. Since the narrow-area beams provide a substantially smaller illumination pattern than the broad-area beam, substantially less power is required to form each narrow-area beam at the satellite antenna so that each additional narrow-area beam results in a frequency reuse with only a relatively small incremental increase in drive power requirements. Because of the reduced incremental satellite power requirements associated with the multiple additional frequency reusages, the high power amplifiers (HPA's) of the satellite transponders for the narrow-area beams can be backed-off from non-linear operation into their linear regions to allow multiple signal carrier amplification in each HPA to thus reduce the total HPA requirements for the system.

Inventors

• 👤 Melvin Barmat

Bibliographic Details