Flexible and Scalable Multiple Access Scheme for the Broadband Mobile Satellite System

摘要

We investigated the design of an optimal multiple access scheme that can accommodate a wide range of applications flexibly for the next-generation mobile satellite system. After comparing several candidate schemes by computer simulation and qualitative analysis, we concluded that multirate frequency division multiple access (MR-FDMA) or orthogonal frequency division multiplexing (OFDM) is best for the forward link and that MR-FDMA is best for the return link. For MR-FDMA to accommodate a wide range of applications efficiently, the symbol rate of each user signal should be switched without quality degradation according to the user's demands or the traffic conditions. For this purpose, a new seamless symbol-rate-switchable modem has been developed. Its fundamental performances were confirmed by computer simulation.