Whenever multibeam satellite systems target very aggressive frequency reuse in their coverage area, inter-beam interference becomes the major obstacle for increasing overall system throughput. As a matter of fact, users located at beam edges suffer from large even moderately planning reuse-2. Although solutions management have been investigated terminal, it turns out that performance improvement does not justify increased terminal complexity and cost. In this article, we pay attention to...

This paper considers a wireless communication system with multiple transmit and receive antennas, i.e., multiple-input-multiple-output (MIMO) channel. The objective is to design the transmitter according an imperfect channel estimate, where errors are explicitly taken into account obtain robust under maximin or worst case philosophy. transmission scheme composed of orthogonal space-time block code (OSTBC), whose outputs transmitted through eigenmodes estimate appropriate power allocation...

This paper deals with the problem of precoding in multibeam satellite systems. In contrast to general multiuser multiple-input-multiple-output (MIMO) cellular schemes, architectures suffer from different challenges. First, communications standards embed more than one user each frame order increase channel coding gain. leads so-called multigroup multicast model, whose optimization requires computationally complex operations. Second, when data traffic is generated by several Earth stations...

This Letter addresses the statistical modeling of dual-polarized MIMO-LMS fading channels. In absence accurate experimental results, a model for characterization channels is proposed based on consolidation available results SISO-LMS and MIMO wireless as well their extrapolation to case interest. Moreover, step-by-step methodology simulation time-series generation channel provided, which useful design performance assessment transmission systems. The incorporates effects all relevant critical...

Next-generation communication systems have to comply with very strict requirements for increased flexibility in heterogeneous environments, high spectral efficiency, and agility of carrier aggregation. This fact motivates research advanced multicarrier modulation (MCM) schemes, such as filter bank-based (FBMC) modulation. paper focuses on the offset quadrature amplitude (OQAM)-based FBMC variant, known FBMC/OQAM, which presents outstanding efficiency confinement a number channels...

This paper focuses on spectrum handoffs in a cognitive radio network where secondary (unlisenced) users (i.e. radios) opportunistically use frequency channels as long the aggregate interference caused at primary (licensed) does not exceed certain threshold. When harmful is to user, or when quality of service perceived by user satisfactory, has initiate handoff quickly vacate channel it occupying. The proposal this fuzzy-based approach able make effective decisions context characterized...

In this Letter, a low-complexity Euclidean distance-based method for antenna subset selection in Spatial Modulation systems is presented. The proposed avoids the high complexity of both optimal exhaustive search and recently algorithm performing selection. Moreover, as number receive antennas increases practical signal-to-noise ratio (SNR) values, it offers better error performance than conventional transmit (TAS) algorithm. addition, benefits scheme, increases, are further substantiated by...

Next generation high throughput satellite systems are expected to rely on the deployment of a number beams in user link, and therefore operate an interference limited regime. This paper builds combination advanced mitigation techniques ground based beamforming cope with this increased level among users. Focussing forward link multi-beam broadband system, we consider joint design linear precoding at gateway. is modeled, different considered for comparison. The provided simulation results...

The field of satellite communications is enjoying a renewed interest in the global telecom market, and very high throughput satellites (V/HTS), with their multiple spot-beams, are key for delivering future rate demands. In this article, state-of-the-art open research challenges signal processing techniques V/HTS systems presented first time, focus on novel approaches efficient interference mitigation. main topics ground, satellite, user segment addressed. Also, critical components...

This paper considers a multigateway multibeam satellite system with multiple feeds per beam. In these systems, each gateway serves set of beams (cluster) so that the overall data traffic is generated at different geographical areas. Full frequency reuse among considered interference mitigation techniques are mandatory. Precisely, this aims designing precoding scheme which, in contrast to single schemes, entails two main challenges. First, matrix shall be separated into feed groups assigned...

This paper deals with the problem of precoding, scheduling, and link adaptation in next generation mobile interactive multibeam satellite systems. In contrast to fixed services, when user terminals move across coverage area, additional challenges appear. Due time varying channel, gateway has only access a delayed version channel state information (CSI), which can eventually limit overall system performance. However, general multiuser multiple-input multiple-output terrestrial systems, CSI...

This paper introduces a novel technique, clustered cell-free massive-MIMO (C <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> F-M-MIMO), that generalizes the recently proposed massive MIMO (CF-M-MIMO) concept by optimizing connectivity pattern among access points (APs) and mobile stations (MSs). Relying on popular K-means clustering algorithm, APs MSs are grouped together in clusters such way strong interferers arising due to pilot...

In real-time and high-resolution Earth observation imagery, Low Orbit (LEO) satellites capture images that are subsequently transmitted to ground create an updated map of area interest. Such maps provide valuable information for meteorology or environmental monitoring, but can also be employed in near-real time operation disaster detection, identification, management. However, the amount data generated by these applications easily exceed communication capabilities LEO satellites, leading...

This paper studies the MIMO applicability to filter bank based multicarrier (FBMC) modulations for low coherence bandwidth channels. Under these conditions channel frequency response cannot be modeled flat at a subcarrier level. implies that techniques originally devised OFDM do not restore orthogonality between subcarriers when they are directly applied FBMC. Aiming circumventing this problem we propose design of two FBMC schemes, which on new subband processing. The figures merit govern...

As the demand for higher throughput satellites increases, multibeam architectures with smaller beam spots are becoming common place. If same frequency is strongly reused, resulting interference when serving simultaneously many users requires some sort of pre or post-cancelation process. This article focuses on precoding and multiuser detection schemes satellites, comparing hybrid on-board on-ground beamforming techniques fully ground-based beamforming. Both rely exchange radiating element...

The Internet of Things (IoT) will facilitate a wide variety applications in different domains, such as smart cities, grids, industrial automation (Industry 4.0), driving, assistance the elderly, and home automation. Billions heterogeneous devices with application requirements be connected to networks generate huge aggregated volumes data that processed distributed cloud infrastructures. On other hand, there is also general trend deploy functions software (SW) instances infrastructures [e.g.,...

Non-orthogonal transmission is a promising technology enabler to meet the requirements in 5G communication systems.Seminal papers demonstrated that nonorthogonal multiplexing techniques outperform orthogonal schemes terms of capacity, latency and user fairness.Since it envisioned satellites will be an integral component infrastructure, worth studying how satellite systems can benefit from application non-orthogonal as well.Contrary common perception, current communications through present...

Next-generation satellite systems require more flexibility in resource management such that available radio resources can be dynamically allocated to meet time-varying and non-uniform traffic demands. Considering potential benefits of beam hopping (BH) non-orthogonal multiple access (NOMA), we exploit the time-domain multi-beam by optimizing BH design, enhance power-domain via NOMA. In this paper, investigate synergy mutual influence We jointly optimize power allocation, scheduling,...

Modern satellites deployed in low Earth orbit (LEO) accommodate processing payloads that can be exploited for edge computing. Furthermore, by implementing inter-satellite links, the LEO a constellation route data end-to-end (E2E). These capabilities to greatly improve current store-and-forward approaches surveillance systems. However, they give rise an NP-hard problem of joint communication and computing resource management (RM). In this paper, we propose algorithm allows select between...

This paper proposes a novel split learning architecture designed to exploit the cyclical movement of Low Earth Orbit (LEO) satellites in non-terrestrial networks (NTNs). Although existing research focuses on offloading tasks NTN infrastructure, these approaches overlook dynamic patterns LEO that can be used efficiently distribute task. In this work, we analyze how satellites, from perspective ground terminals, participate time-window-based model training. By splitting between and terminal,...

Orthogonal frequency division multiplexing (OFDM) has been recently established for several systems such as HiperLAN/2 and Digital video/audio broadcasting, due the easy implementation of modulator/demodulator equalizer. Moreover, also increasing interest is currently being put on multiple-input multiple-output (MIMO) channels, based use antenna arrays at both transmitter receiver. Here, we propose two joint beamforming strategies low computational load combining OFDM MIMO. The ultimate...

This paper addresses the joint design of MIMO precoding and decoding matrices for filter bank multicarrier (FBMC) systems based on OQAM, known as FBMC/OQAM. Existing solutions that support multi-stream transmission only give satisfactory performance in scenarios with high coherence bandwidth channels. To make progress towards application FBMC/OQAM to channels, we study novel provide robustness against channel frequency selectivity transmission. this end, two techniques have been devised...

This paper deals with the problem of non-orthogonal multiple access (NOMA) in multibeam satellite systems. In current NOMA approach, it is assumed a successive interference cancellation (SIC) receiver. To increase spectral efficiency, simultaneous non-unique detection (SND) investigated. Since conventional scheduling heuristic rules do not longer apply this scenario, different algorithms have been proposed. The numerical results show that SND yields larger average data rates and more...

In this paper, we consider the cognitive satellite uplink where terminals reuse frequency bands of Fixed-Service (FS) terrestrial microwave links which are incumbent users in Ka 27.5–29.5 GHz band. scenario, transmitted power has to be controlled so as satisfy interference constraints imposed by FS receivers. We investigate and analyze a set optimization frameworks for rate allocation problem considered scenario. The main objective is shed some light on rather unexplored scenario demonstrate...