Shannon Wireless’ Post

#Low #earth #orbit (#LEO) satellite communication systems have gained increasing attention as a crucial supplement to terrestrial wireless networks due to their extensive coverage area. This letter presents a novel system design for LEO satellite systems by leveraging #stacked #intelligent #metasurface (#SIM) technology. Specifically, the lightweight and energy-efficient SIM is mounted on a satellite to achieve multiuser beamforming directly in the electromagnetic #wave #domain, which substantially reduces the processing delay and computational load of the satellite compared to the traditional digital beamforming scheme. To overcome the challenges of obtaining instantaneous #channel #state #information (#CSI) at the transmitter and maximize the system’s performance, a joint power allocation and SIM phase shift optimization problem for maximizing the ergodic sum rate is formulated based on statistical CSI, and an #alternating #optimization (#AO) algorithm is customized to solve it efficiently. Additionally, a user grouping method based on channel correlation and an antenna selection algorithm are proposed to further improve the system performance. ---- Shining Lin, Jiancheng An, Lu Gan, Mérouane Debbah, Chau Yuen More details can be found at this link: https://lnkd.in/gKy8EaHa

#Low #earth #orbit (#LEO) satellite communication systems have gained increasing attention as a crucial supplement to terrestrial wireless networks due to their extensive coverage area. This letter presents a novel system design for LEO satellite systems by leveraging #stacked #intelligent #metasurface (#SIM) technology. Specifically, the lightweight and energy-efficient SIM is mounted on a satellite to achieve multiuser beamforming directly in the electromagnetic wave domain, which substantially reduces the processing delay and computational load of the satellite compared to the traditional digital beamforming scheme. To overcome the challenges of obtaining instantaneous #channel #state #information (#CSI) at the transmitter and maximize the system's performance, a joint power allocation and SIM phase shift optimization problem for maximizing the ergodic sum rate is formulated based on statistical CSI, and an #alternating #optimization (#AO) algorithm is customized to solve it efficiently. Additionally, a user grouping method based on channel correlation and an antenna selection algorithm are proposed to further improve the system performance. ---- Jiancheng An, Merouane Debbah More details can be found at this link: https://lnkd.in/gKy8EaHa

This survey provides an holistic overview of opportunistic #Low #Earth #Orbit (#LEO)-#Positioning, #Navigation, and #Timing (#PNT) and an exhaustive review of the academic work in the field. Error sources and challenges with respect to the development of operational systems are evaluated, and the state-of-the-art performance is analyzed. System-level strategies to mitigate the error sources and challenges are identified, including the combination of opportunistic LEO-PNT with #Global #Navigation #Satellite #Systems (#GNSS) or other sensors, or the use of base stations. Future research directions, such as the investigation of non-accuracy related #KPIs, the required receiver hardware, or the use in #low #SNR scenarios, are derived.----Winfried Stock, @Robert T. Schwarz, @Christian A. Hofmann, Andreas Knopp More details can be found at this link: https://lnkd.in/gvpHg3qx

🚀 Excited to share the submission of our new conference paper as part of ANTERRA: Antenna Systems Experts for 6G Non-Terrestrial Networks intitled "Soft Handover Strategy in Low Earth Orbit Satellite Networks; how strong the inter-satellite link should be" conducted in collaboration with Alberto Tarable,Alessandro Nordio, and Behrooz Makki 🛰️ Our paper focuses on the advantages of employing soft handover techniques, particularly in the uplink. We establish a realistic model for both ground-to-satellite and inter-satellite links. Key highlights of our findings include: 1- Quantification of the loss incurred by hard handover compared to soft handover through comprehensive simulations. 2- Evaluation of amplify-and-forward (AF) and decode-and-forward (DF) relaying techniques during handover, with a particular emphasis on block error rate (BLER). 3- Exploration of the impact of LEO constellation size on network BLER. 4- Revelation of the impact of misalignment on inter-satellite links, especially at optical frequencies, under soft handover scenarios. Our research sheds light on the crucial role soft handover plays in enhancing the performance and reliability of LEO satellite networks, offering valuable insights for future developments in the field. Read the full paper on arXiv: https://lnkd.in/dnSHuPTr #LEOSatellite #HandoverStrategy #ResearchPublication #Networking #SatelliteCommunication #Ericsson #CNR #IEEE #Wireless #Communicatins #WirelessCommunication #MonteCarlo #SignalProcessing #3GPP #6G #5G #Beyond5G #Handover #InterSatellitesLinks

This paper attempts to provide an initial assessment of the feasibility and potential gains of #adaptive #wideband #cellular #systems operating across the upper mid-band. The study includes: (1) a detailed ray tracing simulation to assess potential gains of multi-band systems in a representative dense urban environment and illustrate the value of a wideband system with dynamic frequency selectivity; (2) an evaluation of potential cross-interference between satellites and terrestrial cellular services and interference nulling to reduce that interference; and (3) design and evaluation of a compact multi-band antenna array structure. Leveraging these preliminary results, we identify potential future research directions to realize next-generation systems in these frequencies. ---- Seongjoon Kang, Marco Mezzavilla, Sundeep Rangan, Arjuna Madanayake, Satheesh Bojja Venkatakrishnan, Grégory Hellbourg, Monisha Ghosh, Hamed Rahmani, Aditya Dhananjay More details can be found at this link: https://lnkd.in/eRKpiu3R

This paper proposed a novel #stochastic #geometry #framework to study the #downlink #coverage #performance in a #millimeter #wave (#mmWave) cellular network by jointly considering the polar coordinates of the #Base #Stations (#BSs) with respect to the typical user located at the origin. Specifically, both the Euclidean and the #angular #distances of the BSs in a maximum power-based association policy for the #user #equipment (#UE) are considered to account for realistic beam management considerations, which have been largely ignored in the literature, especially in the cell association phase. For completeness, two other association schemes are considered and exact-form expressions for the coverage probability are derived. Subsequently, the key role of angular distances is highlighted by defining the dominant interferer using angular distance-based criteria instead of Euclidean distance-based, and conducting a dominant interferer-based coverage probability analysis. ---- Harris K. Armeniakos, Athanasios (Thanasis) Kanatas, Harpreet Dhillon More details can be found at this link: https://lnkd.in/eGqS8DFC

Check out our new publication "Multi-stream STGAN: A Spatiotemporal Image Fusion Model with Improved Temporal Transferability" published in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing (https://lnkd.in/gGyq5hVy). We proposed a multistream spatiotemporal fusion generative adversarial network (STGAN) model for spatiotemporal satellite image fusion that can produce accurate fused images and accommodate substantial temporal differences between the input images.

💠[#SIM] An emerging #Stacked #Intelligent #Metasurface (SIM) technology consisting of multiple metasurfaces is capable of carrying out signal processing and computations naturally as electromagnetic waves pass through it, without causing additional latency and energy consumption. SIM offers a solution for ultra-fast downlink beamforming in the wave domain, which is beneficial for reducing processing delays in #satellite #communication systems. Recently, a SIM-enabled downlink satellite communication system has been developed to perform the #wave-#domain #beamforming relying on #statistical #channel #state #information (#CSI). To serve multiple users in the area with a higher sum rate, the authors proposed an effective user grouping method and an antenna selection scheme. ---- Merouane Debbah More details can be found at this link: https://lnkd.in/gKy8EaHa Please watch the presentation video at this link: https://lnkd.in/g3tRMVQQ

This paper investigates the coverage performance of downlink satellite networks employing dynamic coordinated beamforming. Their approach involves modeling the spatial arrangement of satellites and users using Poisson point processes situated on concentric spheres. The authors derive an analytical expression for the coverage probability which is formulated in terms of various parameters, including the number of antennas per satellite, satellite density, fading characteristics, and path-loss exponent. ----Jeonghun Park, Namyoon Lee More details can be found at this link: https://lnkd.in/dqYZsZHM

This paper focuses on the design of a satellite-based service that broadcast the open access corrections for #Precise #Point #Positioning (#PPP) generated by the #International #Global #Navigation #Satellite #Systems (#GNSS) #Service (#IGS) being appropriate for real-time applications. The proposed system is based on the Argentinian geostationary satellite ARSAT 2 capable of providing service to Latin America. The system requirements and specifications are defined in order to deliver a good quality of service reducing the complexity and the cost of the users receivers. Thoroughly analyzes and calculations carried out demonstrate that, adopting practical design criteria, a low-cost implementation is possible. The authors present the main characteristics of the uplink ground station and downlink user receivers. Moreover, different user receiver architectures as well as the design of a simple antenna are proposed. ---- Ramón López La Valle, Ernesto Lopez, Javier Garcia More details can be found at this link: https://lnkd.in/eTCh6hAR