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Future internet demands are being increased dramatically year by year. Terrestrial systems are unable to satisfy these demands in all geographical areas and thus broadband access by satellite is a key service provision platform. Considering the traffic demands, the raw capacity should approach a Terabit/s by 2020 to meet these demands. So the challenge is to reduce the cost/bit and to increase the...
Maritime surveillance needs to be improved in order to provide a worldwide, independent of national borders, continuous, systematic and reliable maritime security and safety system for the benefits of end users: EU agencies, Customs, Coast Guard, Navies, Private Ventures, …
Estimation of carrier parameters is of paramount importance in digital communications so as to satisfy the requirements in terms of availability and throughput. This is particularly challenging for systems operated in burst mode, where carrier frequency and phase estimates must be computed for each packet or frame. In this context, the reliability of frequency estimates might be a major problem, in...
The increasing demand for delivering high data rates in Earth Observation systems using Low Earth Orbit (LEO) satellites has led the migration of operating frequency to Ka band. In this high frequency band rain attenuation is the dominant factor for the degradation of the quality of the link and Fade Mitigation Techniques (FMTs) are necessary in order to implement the links. However, FMTs require...
Summary of the main points arising in a study conducted by Beecham Research for the European Space Agency - SAMOS (SAtellite M2m Observatory Study). This provides the basis for conference presentation slides.
Multi-channel Early Warning Systems are currently used to warn the population at risk and reduce the impact of crisis. Nevertheless, satellite networks, which offer robust and reliable communication solutions during major disaster events, are not yet being fully considered for direct communication to the citizens. The paper will address solutions for the transmission of alert messages to warn/inform...
With an increasingly capable and complex European Security landscape, Space technologies are playing a vital role in crisis response both within Europe and across the globe. In this domain, Europe is developing capabilities to address many useful space technology applications that are directly applicable to both civilian and security needs. As expressed by various actors in the civil security and...
The growing demand for two-way broadband satellite services has pushed for the development of the DVB-RCS2 standard to improve the performance of the reverse link. Among the enhancements brought by the new standard, a wide range of modulation and coding schemes allows Interference and Fading Mitigation Techniques (IFMTs) to more efficiently exploit the diverse temporal and geographical propagation...
Due to increasing demand of high speed data rate for satellite multimedia and broadcasting services and spectrum scarcity problem in satellite bands, exploring new techniques for enhancing spectral efficiency in satellite communication has become an important research challenge. In this aspect, satellite cognitive communication can be considered as a promising solution to solve spectrum scarcity problem...
Integrating terrestrial and satellite communications promises several advantages, whereas the most evident one is that modern satellite networks achieve global coverage using a multiple spot beam architecture. In order to increase the spectral efficiency, orthogonal waveforms like single-carrier frequency-division multiple access (SC-FDMA) are investigated recently. In this paper, we verify experimentally...
In this paper we deal with Single Carrier Frequency Division Multiple Access (SC-FDMA) as uplink air interface of broadband satellite networks. Interestingly, SC-FDMA enables a significant increase of the spectral efficiency with respect to the state-of-the-art single-carrier systems. However, as witnessed by the recent specification of the Second Generation DVB Interactive Satellite System (DVB-RCS2)...
Single Carrier FDMA may offer important advantages for satellite networks, for instance in terms of increased spectral efficiency, compared to classic MF-TDMA multiple access schemes. This work studies the performance of synchronization procedures and provides indications on the system sizing when SC FDMA is employed over the return link of a GEO satellite system. It is shown how a DVB-RCS like closed...
SAT-AIS is gaining momentum thanks to the push of the users and to the different ongoing institutional and private initiatives. System performance characterization is a central task for the system design, as the constellation has to be sized efficiently to meet the user requirements. However due to the complexity of the systems, often composed of more than 10 satellites in a LEO constellation, this...
The use of erasure codes in space communications has proved to be promising in order to make communication more robust against both independent and correlated data losses. In particular, erasure codes are an appealing solution to provide space communications with increased reliability, especially in scenarios where large latencies make the use of automatic repeat request (ARQ) strategies problematic...
Information about the channel state is particularly useful for adapting transmission parameters to different fading conditions. With slowly fading channels, the signal-to-noise ratio (SNR) is the most significant figure of merit to obtain the required goals in terms of availability and throughput. Using mobile satellite links, however, the situation may change within the round-trip time. Therefore,...
The presence of a virtual private network over a broadband satellite link creates some issues that must be addressed to avoid degradation on the overall performance. This paper presents these issues and proposes solutions to them from the point of view of the satellite operator. Then, these solutions are evaluated through a set of measurements on a testbed that simulates satellite links connecting...
Integrated systems for provision of both operational and non-operational services are investigated in SANDRA (Seamless Aeronautical Networking through integration of Data-Links, Radios and Antennas). This ultimately comprises integration on the network layer which opposes the hardware segregation of operational and non-operational aeronautical domains. Segregation may in this case be achieved by IPsec...
In this tutorial paper, we first review the main information-theoretic results on channels affected by a time-varying phase noise. The main MAP symbol detection algorithms to be employed in such a challenging scenario are then described considering linear modulations and advanced coding schemes based on iterative detection and decoding. The role of pilot symbols will be also discussed.
The current DVB-S2 standard specifies the use of constant energy level pilots for receiver synchronization and equalization algorithms. However, these are unsuitable for APSK modulations due to the nonlinear response of the satellite power amplifier. In this paper, we investigate the performance of two low-complexity techniques for nonlinear compensation in DVB-S2 systems, i.e. static predistortion...
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