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This paper deals with the performance evaluation of different packet scheduling schemes for Long Term Evolution\ud mobile satellite systems based on the adoption of a multi-user MIMO technique. The major breakthrough of\ud MIMO technology in terrestrial networks has motivated the interest here for the adoption of MIMO in mobile\ud satellite systems as well. In particular, a land mobile dual-polarized GEO satellite system has been considered\ud in this work. The aim of this paper is to propose new cross-layer packet scheduling schemes that achieve a good\ud trade-off among throughput, QoS and fairness and to conduct performance comparisons with other scheduling\ud schemes in the literature. This is the reason why this paper also proposes a new performance index that can be\ud used to evaluate the overall performance of each scheduler. The work shows that the new cross-layer scheduler,\ud called channel-based queue sensitive scheduler, attains the best performance in terms of the new comprehensive\ud performance index, thus representing an interesting solution for future mobile satellite systems

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In this paper, the performance analysis of a reconfigurable intelligent surface (RIS) in a dualhop decode-and-forward (DF) relay empowered asymmetric radio frequency (RF)/free space optical (FSO) systems is presented. The RIS-assisted RF network is subjected to Nakagami-m distribution while the RIS-assisted FSO networks experience Gamma-Gamma distribution in which both atmospheric turbulence and pointing errors are considered. Thus, the closed-form expressions for the system outage probability and average bit error rate (ABER) are derived with limited number of reflecting elements at RIS-assisted RF network and multiple number of reflecting elements at RIS-assisted FSO network. Further, to obtain more insight about the system characteristic, the asymptotic closed-form expressions are derived at high signal-tonoise ratio (SNR) for the system performance metrics. The results illustrate the impact of the system and channel parameters on the proposed system in terms of atmospheric turbulence, pointing errors under beam width condition, 𝑚-fading parameter, and number of reflecting elements. The correctness of the derived analytical expressions is validated via the Monte-Carlo simulations.

This paper investigates the impact of the Round Trip Propagation Delay (RTPD) in the satellite LTE air interface with the adoption of MIMO technology. The Satellite LTE air interface will provide global coverage and hence complement its terrestrial counterpart in the provision of LTE services to mobile users. A land mobile dual-polarized GEO satellite system has been considered for this work. The link adaption is an important module for the scheduling scheme and the satellite LTE network as a whole in order to make optimal scheduling decisions and effectively utilize the network resources respectively. However, the long RTPD experienced when Channel Quality Indicator (CQI) is reported from the User Equipment (UE) to the eNodeB via GEO satellite causes misalignment between the reported CQI at the eNodeB and the present CQI of the mobile user. The aim of this paper is to investigate the effect of the misalignment as a result of long RTPD through simulations and also investigate the effect of varying CQI reporting interval on the system performance of Satellite LTE network. The possibility of using a fixed CQI rather than an adaptive CQI is also investigated.

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