Mobile TDM/TDMA system with active array antenna

A multicarrier time-division multiple-access (TDMA) system is proposed for future mobile satellite communications systems that include a multisatellite system. This TDMA system uses an active array antenna in which the digital beamforming technique is adopted to control the antenna beam direction. The antenna beamforming is carried out at the baseband frequency by using digital signal processing. In the proposed system, TDM/TDMA with a time-division duplex technique is adopted for the satellite link between the mobile earth station and the HUB station in order to remove the diplexer from each mobile antenna element.<
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