Spectrally Efficient Waveforms for the Return Link in Satellite Communication Systems

In this paper, we study the applicability of terrestrial mobile waveforms in the return link of a high throughput satellite (HTS) communication system. These include orthogonal frequency division multiple access (OFDMA), single-carrier frequency division multiple access (SC-FDMA) and filter bank multi-carrier (FBMC). Key solutions to the challenges in a geostationary orbit (GEO) satellite channel, such as synchronization and non-linear distortion, are presented. A global-positioning-system-(GPS)-based approach for synchronization acquisition is proposed, while suitable algorithms are studied for timing/frequency offset estimation and synchronization tracking. The spectral and power efficiencies of the schemes are optimized by means of an intermodulation interference (IMI) cancelling receiver, and these are compared to state-of-the-art time division multiple access (TDMA). Finally, end-to-end simulations validate the system performance

On the role of satellite communications for emergency situations with a focus on Europe

International audienceIn this paper, we describe how satellite communications may contribute to disaster management. During emergency situations, satellite communications present many advantages in supporting or replacing a terrestrial infrastructure (if any) subject to destruction or saturation. However, devising the right deployment model deserves close scrutiny in order to fit the responders’ needs and sustain financial viability. After reading the paper, we expect that the answers to the following questions will be made clear: what are the roles of telecommunications in emergency situations? How can satellite technologies help? How to mitigate the cost of deploying and using satellite facilities? Who are the actors currently involved in emergency telecommunications and more specifically satellite-assisted emergency telecommunications

SYSTEMS, ENABLING TECHNOLOGIES AND METHODS FOR DISTANCE LEARNING: THE STEEL PROJECT

media e diverse modalità di comunicazione, e al tempo stesso consenta la fruizione dei corsi erogati da piattaforme stazionarie o mobili. A tale scopo il sistema si basa su un’infrastruttura tecnologica innovativa di tipo satellitare-terrestre. Scopo di questo contributo è presentare il progetto nel suo complesso. In primo luogo verranno illustrati i requisiti metodologici e didattici che sono stati individuati per il corso pilota che verrà erogato nell’ambito degli insegnamenti di un corso di laurea a distanza. Si intende quindi spiegare quali siano i criteri ed il percorso che hanno condotto alla configurazione della piattaforma, con particolare attenzione alla necessità di integrare erogazione sincrona ed asincrona dei corsi online. Verrà infine illustrata la piattaforma hard-ware realizzata per la gestione della qualità del sistema su reti eterogenee. Summary: The aim of the STEEL (Systems, enabling TEchnologies and mEthods for distance Learning) project is to develop a complete e-learning system based on an innovative integrate