Results 51 to 60 of about 86,758,594 (170)

Free Space Ground to Satellite Optical Communications Using Kramers–Kronig Transceiver in the Presence of Atmospheric Turbulence

Sensors, 2022
Coherent detection provides the optimum performance for free space optical (FSO) communication systems. However, such detection systems are expensive and require digital phase noise compensation.
Mahdi Naghshvarianjahromi, Shiva Kumar, M. Jamal Deen   +2 more
doaj   +1 more source

Interventional Root‐Cause Analysis of Quality‐of‐Service Degradation in LEO Satellite‐User Assignment

International Journal of Network Management, Volume 36, Issue 5, September/October 2026.
ABSTRACT Operators of low Earth orbit (LEO) access networks increasingly diagnose quality‐of‐service (QoS) degradation with observational machine‐learning attribution, yet when the candidate causes are produced by the resource‐management policy itself, observational attribution is unsafe: it assigns the degradation to factors that an operator cannot ...
Edson José Pacheco, Carlos Marcelo Pedroso   +1 more
wiley   +1 more source

Performance of Multibeam Satellite Systems with Tomlinson-Harashima Precoding [PDF]

, 2009
A multibeam satellite system can be modelled as a multiple-input multiple-output (MIMO) system with an interbeam interference matrix that is derived from the positions of the users in the different beams.
Banelli, Paolo, Berioli, Matteo, Poggioni, Mario   +2 more
core  

Satellite-based entanglement distribution and quantum teleportation with continuous variables

Communications Physics
Advances in satellite quantum communications aim at reshaping the global telecommunication network by increasing the security of the transferred information.
Tasio Gonzalez-Raya, Stefano Pirandola, Mikel Sanz   +2 more
doaj   +1 more source

Overcoming the Phase Discontinuity Problem in RIS Optimization: A Robust and Scalable Phase‐Aware Deep Regression Framework via Hybrid CNN–LSTM Architecture

Advanced Intelligent Systems, Volume 8, Issue 9, September 2026.
The phase discontinuity problem—where the cyclic nature of phase angles causes catastrophic errors near the ±π boundary—is a fundamental obstacle in learning‐based reconfigurable intelligent surface (RIS) optimization. A phase‐aware hybrid CNN–LSTM framework resolves this by decomposing phase predictions into sine–cosine components, mapping circular ...
Seda Savaşçı Şen, Ali Çalhan, Murtaza Cicioğlu, Oğuzhan Demiryürek   +3 more
wiley   +1 more source

Design of the Integration and Technical Verification and Validation Phase of the Ground Segment of the Hyperspectral Satellite Mission EnMAP [PDF]

, 2011
EnMAP (Environmental Mapping and Analysis Program) is a German hyperspectral satellite mission, with a ground segment operated by the Earth Observation Center (EOC) and the German Space Operation Center (GSOC) of the German Aerospace Center (DLR).
Makasy, Christine, Storch, Tobias, Missling, Klaus-Dieter, Mühle, Helmut, Müller, Rupert, de Miguel, Amaia, Eberle, Sabrina, Habermeyer, Martin   +7 more
core  

FedGATE: Topology‐Aware Personalized Federated Learning With Utility and Carbon‐Aware Scheduling for Mobile Traffic Prediction

Concurrency and Computation: Practice and Experience, Volume 38, Issue 18, September 2026.
ABSTRACT Accurate mobile traffic prediction is important for proactive resource allocation, congestion management, and service assurance in fifth‐generation and emerging sixth‐generation networks. Centralized deep‐learning approaches can provide strong forecasting performance but require raw traffic data to be transferred to a common server, creating ...
Muhammad Qasim, Muhammad Imran, Muhammad Ahmad Bilal, Adil Masood Siddiqui, Maryam Rasool, Muhammad Junaid Khan, Hassan Khan   +6 more
wiley   +1 more source

Current optical technologies for wireless access [PDF]

, 2009
The objective of this paper is to describe recent activities and investigations on free-space optics (FSO) or optical wireless and the excellent results achieved within SatNEx an EU-framework 6th programme and IC 0802 a COST action.
Sheikh Muhammed, S., Ghassemlooy, Zabih, Javornik, Tomaz, Kandus, Gorazd, Awan, Muhammad, Brandl, P., Capsoni, Carlo, Leitgeb, Erich, Nebuloni, R.   +8 more
core  

Lunar Trailblazer Spacecraft Tracking and Mission Recovery Attempt: Characterization of Status and Behavior of a Non‐Cooperative Object in Cis‐Lunar Space

Earth and Space Science, Volume 13, Issue 8, August 2026.
Abstract Unexpectedly following launch, the Lunar Trailblazer mission experienced software anomalies that led it to orient solar panels away from the sun and lose communication with Earth. This paper describes efforts to determine the spacecraft state and attempt recovery of the mission's science at the Moon.
B. L. Ehlmann, J. Bellerose, G. Lantoine, E. Furlan, E. Scire, S. Fajardo‐Acosta, L. Bennett, M. Sanchez Net, T. J. W. Lazio, M. Brozović, J. Masiero, A. V. Steckel, P. A. Burke, M. Kimura, S. Foxman, M. P. M. Zaw, L. M. Lee, F. Clarke, M. Hauge, D. McDonald, J. Adler, R. Strauss, D. Trilling, C. S. Edwards, M. C. Nolan, D. Lyster, L. Robinson, A. T. Klesh, C. C. Seybold   +28 more
wiley   +1 more source

HELIOS ‐ Highly rEliable Links durIng sOlar conjunctionS

Radio Science, Volume 61, Issue 8, August 2026.
Abstract During deep space missions, maintaining reliable communication between a spacecraft and Earth becomes particularly challenging during superior solar conjunctions, when the spacecraft passes behind the Sun relative to Earth. The highly ionized solar corona and solar wind create plasma inhomogeneities that severely affect radio signals, leading ...
A. Zeqaj, P. Tortora, E. Paolini, A. J. Stocker, D. R. Siddle, A. Argyriou, J. De Vicente, R. Abello, M. Mercolino   +8 more
wiley   +1 more source