Shannon Wireless’ Post

This study delves into the potential of harnessing the #orbital #angular #momentum (#OAM) property of electromagnetic waves in near-field and line-of-sight scenarios by utilizing large intelligent surfaces, in the context of holographic #multiple-#input #multiple-#output (#MIMO) communications. The paper starts by characterizing OAM-based communications and investigating the connection between OAM-carrying waves and optimum communication modes recently analyzed for communicating with smart surfaces. Subsequently, it proposes implementable strategies for generating and detecting OAM-based communication signals using intelligent surfaces and optimization methods that leverage focusing techniques. Then, the performance of these strategies is quantitatively evaluated through simulations. ---- Giulia Torcolacci, Nicolò Decarli, Davide Dardari More details can be found at this link: https://lnkd.in/eaX7KwgJ

🎯 𝐋𝐚𝐢𝐐𝐚 𝐏𝐫𝐨𝐣𝐞𝐜𝐭 𝐎𝐛𝐣𝐞𝐜𝐭𝐢𝐯𝐞 #4 🎯 🚀 LaiQa Project will rely on Rare Earth Ion-Doped (REID) platform to develop a QM, namely Er:SO2 and Er:YSO. 👉 REID platforms are suitable due to their direct integration with 1550 nm telecommunication devices, compatibility with current laboratory infrastructure, and favourable operating temperatures. ✅ The QM system will achieve single-photon storage time of 0.1 μs, memory efficiency of 1% fidelity of 95%, and bandwidths in the order of tens of GHz, allowing for at least two spectral modes to be simultaneously stored in the memory. 🌐 The QM will be integrated with the PICbased source to demonstrate a quantum echo for the development of a highly #quantum information network. Click to find out more 🔗https://lnkd.in/dRh9cq6U #LaiQa #QuantumCommunication #science #technology #research #horizoneurope #photonics #eufunded #space

The first objective of this work is the design of #swarm-#based #antenna #arrays, in which the impact of key parameters such as the number of satellites in the swarm, their reciprocal distance and the array geometry, is thoroughly analyzed. It is shown that the undesired phenomenon of grating lobes can be mitigated via optimized array geometries and a new geometry named the #enhanced #logarithmic #spiral #array (#ELSA) is presented. The second objective of this work is the identification of the most important research directions and system design aspects for the #swarm #system. In particular, it is shown that tethered swarms with ELSA geometries, innovative deployable structures and very small satellites can foster the deployment of swarms in future satellite systems. ---- Diego Tuzi, Thomas Delamotte, Andreas Knopp More details can be found at this link: https://lnkd.in/eAEKtfcK

This paper proposes a #novel #feeder #link switch over procedure, which exploits #intersatellite #links (#ISLs) to implement, through a chain of #Low-#Earth #Orbit (#LEO) satellites, virtual visibility between a LEO satellite and an #Non-#Terrestrial #Networks (#NTNs)-#Gateway (#GW) that are not in direct sight. This aims at reducing the time of feeder link switch over and avoiding service disruptions. The advantages of the proposed “ISL-aided” feeder link switch over procedure over the one defined by #Third #Generation #Partnership #Project (#3GPP) are assessed via simulative campaigns.----Sara Pizzi, Federica Rinaldi, Antonio Iera, Antonella Molinaro, Giuseppe Araniti More details can be found at this link: https://lnkd.in/gTRsC9gk

This paper introduces a novel approach to maximize #low #Earth #orbit (#LEO) satellite coverage by leveraging #reconfigurable #intelligent #surface (#RIS) within 6G sub-#terahertz (#THz) networks. Optimization objectives include improving #end-#to-#end (#E2E) data rate, optimizing satellite-#remote #user #equipment (#RUE) associations, data packet routing within satellite constellations, RIS phase shift, and #ground #base #station (#GBS) transmit power (i.e., active beamforming). The formulated joint optimization problem poses significant challenges because of its time-varying environment, non-convex characteristics, and NP-hard complexity. To address these challenges, they propose a #block #coordinate #descent (#BCD) algorithm that integrates balanced K-means clustering, #multi-#agent #proximal #policy #optimization (#MAPPO) #deep #reinforcement #learning (#DRL), and #whale #optimization #algorithm (#WOA) techniques. ---- Sheikh Salman Hassan, Ph.D., Yu Min Park , Yan Kyaw Tun, Walid Saad , Zhu Han , Choong Seon Hong More details can be found at this link: https://lnkd.in/eQmHxryW

Graphene Stronger than Stone 🪨. More powerful than anything else. Faster analysis on TV screens. Faster recharging time for batteries. https://lnkd.in/e_TA4zTU

In this work, the authors provide a mobility performance analysis through extensive system-level simulations of state-of-the-art #handover (#HO) procedures for 5G #New #Radio (#NR) over #Low-#Earth #orbit (#LEO) satellite networks with Earth-moving cells. Furthermore, this article presents a novel antenna gain-based HO solution for intra-satellite mobility that exploits the predictability of the satellites movement and the antenna gain of the satellite beams, making #user #equipment (#UE)’s radio measurements obsolete. The system-level simulation results, which consider users in rural and urban scenarios, show that by exploiting the known satellite’s trajectory, the UE eliminates service failures and undesired HO events, maximises the time-of-stay in a cell and experiences improved downlink signal-to-interference-plus-noise ratio. ---- Enric Juan , Mads Lauridsen, Jeroen Wigard, Preben Mogensen More details can be found at this link: https://lnkd.in/e6P4FscE

The Fascinating Doppler Effect 🌟 The Doppler effect is a truly remarkable phenomenon that brings about a change in the frequency or wavelength of a wave when an observer is in motion relative to the wave source. It encompasses a diverse range of waves, including sound 🎙️, light 💡, and radio waves 📻. Consider the example of a police car with its siren blaring. As the vehicle approaches, the pitch of the siren appears higher, and as it moves away, the pitch decreases. This is a clear manifestation of the Doppler effect in the realm of sound waves. 🔊 In the field of astronomy, the Doppler effect plays a vital role. It is employed to determine the movement of stars and galaxies. A shift towards the blue spectrum indicates that an object is moving closer, while a shift towards the red spectrum suggests it is moving away. This enables astronomers to gain deeper insights into the dynamics of the universe. 🌌 In weather forecasting, Doppler radar is a powerful tool. It emits a radio wave that reflects off moving weather systems. By carefully analyzing the frequency change in the returned waves, meteorologists can accurately determine the speed and direction of storms, providing crucial information for preparedness and safety. 🌩️ The Doppler effect also has a significant impact on frequency oscillators. In communication and navigation systems, it can result in frequency shifts that must be compensated for to ensure accuracy. 📡 The Doppler effect is a fundamental concept with far-reaching implications in numerous fields. Explore more at www.DynamicEngineers.com! 🌐 hashtag #DopplerEffect hashtag #ScientificWonder hashtag #TechApplications hashtag #FrequencyAnalysis hashtag #WavePhysics hashtag #SignalFrequency hashtag #FrequencyShifts hashtag #FrequencyMeasurement hashtag #AstronomyInsights hashtag #WeatherForecasting hashtag #CommunicationInnovation hashtag #NavigationPrecision hashtag #ScientificDiscovery hashtag #DynamicEngineers hashtag #ElectronicsEngineering hashtag #Telecommunications

In this paper, the authors provide the first, fundamental analysis of #Radio #Frequency #Interference (#RFI) that large-scale terrestrial deployments introduce in different satellite sensing systems now orbiting the Earth. They develop a geometry-based analysis and extend it into a data-driven model which accounts for realistic propagation, building obstruction, ground reflection, for network topology with up to 10 5 nodes in more than 85 km 2 . They show that the presence of harmful RFI depends on several factors, including network load, density and topology, satellite orientation, and building density. ---- Paolo Testolina, Michele Polese, Josep Miquel Jornet, Tommaso Melodia, Michele Zorzi More details can be found at this link: https://lnkd.in/eGxupWaU

Crosswell tomography has revolutionized subsurface imaging, offering exceptional resolution for geological studies. With the growing integration of downhole fiber optic cables, acquiring this critical data has become more accessible than ever. In a recent study from the Helmholtz Centre for Environmental Research (UFZ), coauthored by Anna Stork, researchers showcase how Distributed Acoustic Sensing (#DAS) technology can effectively detect downhole P and SV wave sources. By leveraging the high receiver density provided by borehole fiber optics, the fiber itself acts as a powerful antenna, delivering unparalleled resolution for subsurface illumination. Explore the full paper here: https://lnkd.in/gvJmaFEC For more details on the groundbreaking #Carina DAS system, designed for the highest sensitivity in DAS applications, visit: https://lnkd.in/gf5GR-2U #DAS #VSP LUNA Innovations Silixa