Abstract

Satellite communications continue to undergo changes not only from advancing technology, but also from new service and regulatory activities. Therefore, advanced digital satellite communication systems using efficient on-board processing capabilities are required. Signal regeneration on-board the satellite makes it possible to use different multiple access schemes for the uplink and the downlink. The uplink and the downlink can be separately optimized for greater power efficiency and bandwidth utilization. A multiple access scheme using the frequency division multiple access (FDMA) for the uplink and time division multiplex (TDM) for the downlink has been considered for regenerative satellite communications. However, the feasibility of this approach depends on efficient means to directly interface the two multiple access formats on-board the satellite. The conversion from frequency to time division multiplex format requires the uplink signal to be demultiplexed and each individual carrier to be demodulated. The main objective of this thesis is to present the existing symbol timing recovery structures, analyze them and prove the feasibility of the proposed technique which is less complex and that has fast-acquisition characteristics than the conventional techniques