OFDM in mobile satellite systems

Wireless multimedia communications require the selection of a suitable modulation-access technique. OFDM is a potential candidate in the design of such future generation mobile systems; it offers flexibility in bandwidth management, and potential good information protection against the severe degradations induced by the channel on signals characterized by large bandwidths. These attractive features have led to the adoption of OFDM in the design of a wireless LAN, which at the network layer is ATM (project ACTS-MEDIAN). The possibility of interfacing local with satellite networks seems challenging, although OFDM performance over the satellite channel remains to be tested. The present paper reports results of analyses on synchronization issues which show that while satellite-OFDM is in all cases a feasible hypothesis, LEO systems are favoured with respect to GEO, due to the lower delays they introduce