| Abstract: | This paper deals with satellite payload architectures adequate for the provision of universal mobile telecommunication services (UMTS) by medium altitude earth and geostationary orbit (MEO and GEO) satellites. The payload concept introduced is based on a transparent transponder with onboard digital signal processing (DSP) operations and digital beamforming at the traffic carrier level (narrowband beamforming). The emphasis of the paper is on key design aspects and technology considerations of the payload processor unit (PPU), which includes multiplexing/demultiplexing and digital beamforming operations, and on the antenna and RF signal handling subsystems. For completeness, a review on the European digital technology is also presented. The development of such a payload architecture is in line with present and planned activities of the European Space Agency (ESA) for MEO and GEO orbit systems, which are also implicitly discussed in the paper. |
