The paper analyzes the performance of an advanced random access scheme for the return channel of a satellite communication link. The scheme is an evolution of the E-SSA scheme proposed in [1], [2] that couples an asynchronous Spread Spectrum Aloha access with Successive Interference Cancellation (SIC) at the central Gateway (GW) receiver to increase the channel throughput. Main feature of the proposed scheme is the exploitation of an approximate linear Minimum Mean Square Error (MMSE) detector in place of the conventional Single User Matched Filter (SUMF) detector used in E-SSA. A gain of 50% in terms of spectral efficiency is achieved over E-SSA in most typical scenarios.

This paper addresses detailed waveform trade-offs for mesh satellite networks. The waveform analysis is carried out considering spectral efficiency, resilience against non linear distortion, channel impairments and interference for both linear and continuous phase modulation schemes defined in the DVB-RCS2 standard.

In the satellite communications component of the future Internet, peer-to-peer mesh connectivity of satellite terminals is an impellent necessity. In particular, delay sensitive applications such as real-time multimedia, collaborative conferencing and cellular backhauling are appealing use-cases for adopting mesh network topologies. Moreover, the use of a single satellite hop for directly connecting remote terminals (as opposed to a double-hop connection required in star topologies) reduces the satellite traffic load and leads to savings in operational costs of the satellite network. In this paper, we propose a multi-beam satellite mesh network based on a semi-transparent or fully regenerative satellite with different on board switching capabilities. In particular, four network solutions have been assessed in terms of flexibility, complexity and capacity, trading-off between network performance and implementation cost.

In this paper we propose the usage of Single Carrier Frequency Division Multiple Access (SC-FDMA) in the Broadband Satellite Return Channel. Notably, SC-FDMA is able to improve the physical layer spectral efficiency with respect to single carrier systems, which has been used so far in the Return Channel Satellite (RCS) standards. However, it requires a strict synchronization and it is also sensitive to phase noise of local radio frequency oscillators. For this reason, we propose an effective pilot tone arrangement within the SC-FDMA frame, and a novel Joint Multi-User (JMU) estimation method for the SC-FDMA. As shown by numerical results, the proposed scheme manages to satisfy strict synchronization requirements and to guarantee a proper demodulation of the received signal.

This paper will examine the potential performances of spread-spectrum-based access techniques via the interaction channel of an Internet protocol (IP)-based multimedia satellite system. In particular, a theoretical analysis of the spread-Aloha technique will be given for the case of forward error correction coded systems. Then, the performance of spread-Aloha access will be confirmed by simulation and compared with that of a conventional time-division multiple-access (TDMA)-based combined free/demand assignment multiple-access system. It appears that spread-Aloha-based techniques, although achieving a lower maximum throughput than the TDMA-based access scheme, may provide a better experience to the user due to the lower transmission latency. Finally, the prospect of a spread-spectrum-based access scheme combining Aloha and reservation mechanisms will be briefly overviewed.