Special issue on satellite communication systems and networking

information society. In this context, the Q/V band frequencies will play a key role in enabling challenging and unproven broadband communications missions for a wide range of applications and leading to the implementation of Terabit Satellite Networks. The Q/V frequency band may be employed for feeder links, for direct-to(fixed, mobile) user satellite applications and as part of the whole integrated network. Some of these issues are of great interest by European Space Agency as this is testified with the launch of Alphasat in 2012. The focus of this Special Issue is to present high-quality unpublished research papers on recent advances in the wider area of SatCom Systems and Networks by experts from industry, academia, and space agencies. Our call for papers attracted numerous submissions worldwide.

information society. In this context, the Q/V band frequencies will play a key role in enabling challenging and unproven broadband communications missions for a wide range of applications and leading to the implementation of Terabit Satellite Networks. The Q/V frequency band may be employed for feeder links, for direct-to-(fixed, mobile) user satellite applications and as part of the whole integrated network. Some of these issues are of great interest by European Space Agency as this is testified with the launch of Alphasat in 2012. The focus of this Special Issue is to present high-quality unpublished research papers on recent advances in the wider area of SatCom Systems and Networks by experts from industry, academia, and space agencies. Our call for papers attracted numerous submissions worldwide. After a rigorous review process, we present the following six papers.
The first paper entitled "State Modelling of the Land Mobile Propagation Channel for Dual-Satellite Systems" [1] targets on the evaluation and modeling of the multi satellite propagation channel for land mobile users for a high variability of angle diversity constellations presenting results from ESA Project MILADY. Measurements and re-simulated data are analyzed for various elevation angle combinations and azimuth separations in terms of the state probabilities, state duration statistics, and the correlation coefficient.
The second paper entitled "On the Capacity of a SIMO Land Mobile Satellite System at C-Band: Polarized and Depolarized Received Field" [2] evaluates theoretically the capacity of an LMS (SIMO) system utilizing uniform linear arrays at the receiver terminal operating at C Band. Additionally, polarization effects are introduced and capacity results are given taking into account the depolarization.
In the next paper entitled "Enhancement of wireless positioning in outdoor suburban non-line-of-sight (NLOS) environment using hybrid-network-GPS" [3], a method for locating mobile terminal in outdoor suburban NLOS environment, using hybrid-network-GPS system, is introduced. The proposed method uses constraint nonlinear optimization to minimize the NLOS error.
In the fourth paper entitled "Linear and nonlinear techniques for multibeam joint processing in satellite communications" [4], joint multiuser processing techniques for multibeam satellite systems, towards Terabit Satellite Concept, are investigated. More specifically, the performance of linear precoding is examined in the forward link, with optimal nonlinear precoding (i.e., dirty paper coding) acting as the upper performance limit. Similarly, in the return link the concept of linear filtering (i.e., linear minimum mean square error) is studied with the optimal successive interference cancellation acting as the performance limit.
The next paper entitled "Residue code-based low cost SEU-tolerant FIR filter design for OBP satellite communication systems" [5] proposes a dual modules (DM) plus checking module based on residue code (DM-CRC) architecture for SEU-tolerant FIR design. Moreover, a multi-sample checking DM-CRC (MSC-DM-CRC) is further proposed in order to reduce the fault missing rate.
In the last paper entitled "Performance study of multiuser interference mitigation schemes for hybrid broadband multi beam satellite architectures" [6], precoding and multi-user detection schemes for multi beam satellites comparing are examined. Moreover, hybrid onboard on-ground beamforming techniques are compared with fully ground-based beamforming. the papers within the short stipulated time. Their careful reviews and valuable comments helped us select the papers as well as improve the quality of this special issue. We would like to further thank Prof. Luc Vandendorpe, Editor-in-Chief, EURASIP Journal on Wireless Communications and Networking, as well as the whole Editorial Board for their support. Finally, we owe a debt of gratitude to the whole editorial and publications staff of EURASIP Journal on Wireless Communications and Networking that provided us assistance and continuous support throughout the whole process. Part of this work has been carried out under the framework of THALES-NTUA MIMOSA funded by by EU and GSRT. Finally, we hope that the readers will enjoy the contributions on Satellite Communication Systems and Networking in this Special Issue.