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Recently, several activities relating high data rate satellite communications systems have been conducted by CRL in Japan. As the first step of implementation of high data rate (HDR) satellite communications network, CRL starts 155 Mbps ATM/SDH transmission experiment using NTT's new operational satellite N-STAR in December 1995 and the trans-Pacific HDR satellite communications experiment is to be started in April 1996 using Intelsat and NASA's Advanced Communications Technology Satellite (ACTS). To play a major role in the Global Information Infrastructure, satellite communications systems are required to have much higher capacity than 155 Mbps. For realizing gigabit satellite communications systems, CRL already started a study relating to required transponder technology, communications systems and networking technologies. This paper describes detail of these experiments and research project for realizing gigabit satellite communications systems.

The performance of a Direct Sequence Spread Spectrum Communication system in actual land mobile satellite channel is evaluated with experiments. Field test results in L-band with the ETS-V satellite are presented, in which the use of a multi-bitquantized Coherent Matched Filter receiver improves the initial acquisition and the bit error rate performances. The BER characteristics in urban and suburban environments are found to agree with that of nonSS BPSK on a non-selective Rician fading channel.

International audience; We modify the Euclidean algorithm of Feng and Tzeng to decode Reed-Solomon (RS) codes up to the Sudan radius. The basic steps are the virtual extension to an Interleaved RS code and the reformulation of the multi-sequence shift-register problem of varying length to a multi-sequence problem of equal length. We prove the reformulation and analyze the complexity of our new decoding approach. Furthermore, the extended key equation, that describes the multi-sequence problem, is derived in an alternative polynomial way.