950 research outputs found
Multi-Beam LEO Communication Satellite Simulation Framework
No full text<h2>Multi-Beam LEO Communication Satellite Simulation Framework</h2>
<p>With this Python code, the results from the paper <em>Impact of Elevation Angle on Multi-Beam LEO Satellite Communication Systems by Fastenbauer et al.</em> can be reproduced and results with altered parameters can be simulated and plotted. The code also contains the result data used to generate the plots in the paper.</p>
<h2>Multi-Beam LEO Communication Satellite</h2>
<p>This code is a simulation tool to evaluate the channel quality in a multi-beam LEO satellite communication system in terms of signal-to-noise ratio and signal-to-interference-and-noise ratio.</p>
<p>The code simulates a satellite equipped with an antenna array that consists of 19 panels, that each form a beam. The beams are directed to a hexagonal grid on the Earth's surface and independently serve users. The co-channel interference between the beams is taken into account under the assumption that all beams are active at all times.</p>
<h2>Technical details</h2>
<h3>Files</h3>
<ul>
<li><code>figures</code> folder: contains pdf files of the result plots.</li>
<li><code>results</code> folder: contains simulation results saved as JSON files. New results are saved here if no other folder is specified. The saved result files are necessary to run <code>plotResults.py</code>.</li>
<li><code>simulation.py</code>: run simulations.</li>
<li><code>plotResults.py</code>: plot simulation results saved in the results folder.</li>
<li><code>networkGeometry.py</code>: create satellite and user positions and set beam centers.</li>
<li><code>channel.py</code>: functions related to the modeling of wireless transmission channels. Contains functions to calculate free space path loss, atmospheric loss, Rician fading, and array steering vector.</li>
<li><code>utils.py</code>: helper functions.</li>
</ul>
<h3>Required Packages</h3>
<ul>
<li>JSON: save parameters and results in JSON files</li>
<li>NumPy: use of NumPy arrays for calculations</li>
<li>matplotlib.pyplot: plot results</li>
<li>itur: calculate atmospheric losses according to ITU recommendations</li>
<li>astropy.units: required for itur use</li>
</ul>
<h3>Additional Documentation</h3>
<p>The code was used to produce the results in</p>
<p>@ARTICLE{fastenbauer,<br> title={Impact of Elevation Angle on Multi-Beam LEO Satellite Communication Systems}, <br> author={Fastenbauer, Agnes and Kaneko, Megumi and Svoboda, Philipp and Rupp, Markus},<br> year={2025},<br> journal={IEEE Access}<br>}</p>
<p>The paper shows and analyzes the simulation results.</p>
<h2>How to Use</h2>
<h3>Run Simulation and Plot Results</h3>
<p>Run <code>simulation.py</code> to calculate and save simulation results.</p>
<p>Run <code>plotResults.py</code> to plot saved results.</p>
<h3>Change Simulation Parameters</h3>
<p>Use params.py to change simulation parameters such as:</p>
<ul>
<li>satellite altitude in <code>h_satellite</code></li>
<li>carrier frequency in <code>center_frequency</code></li>
<li>transmission bandwidth in <code>bandwidth_Hz</code></li>
<li>number of antenna elements per beam in <code>n_antenna_x </code>and <code>n_antenna_y</code></li>
<li>antenna array gain in <code>antenna_gain_dB</code></li>
<li>Rician K-factor in <code>rician_k</code></li>
<li>transmit power in <code>transmit_power_W</code></li>
<li>receiver noise figure <code>noise_figure_dB</code></li>
</ul>
<p>The footprint size of the satellite serving area can be adjusted in the <code>simulation.py</code> file in the simulation functions by setting <code>r_footprint</code> to the desired footprint radius in meters.</p>
<h3>Use of Code</h3>
<p>When using code, please cite<br>@ARTICLE{fastenbauer,<br> title={Impact of Elevation Angle on Multi-Beam LEO Satellite Communication Systems}, <br> author={Fastenbauer, Agnes and Kaneko, Megumi and Svoboda, Philipp and Rupp, Markus},<br> year={2025},<br> journal={IEEE Access}<br>}</p>
<h3>Acronyms</h3>
<p>ITU: International Telecommunications Union</p>
<p>LEO: low Earth orbit</p>
<h2>Licenses</h2>
<p>The data is licensed under CC-BY, the code is licensed under MIT.</p>
Agnes Grimm Collection
No full textAgnes Grimm was an author and collector of area history. An area school teacher of Texas history, she kept extensive notes, photographs and maps about the history of South Texas and her personal effort to document it. Her book, Llanos Mestenas, was published in 1968
Mag and Agnes
No full textPhotograph - Joe Irwin's Aunt Mag and her oldest sister, Agnes. Vulcan, Albert
Agnes McDonald
No full textHead shot of Agnes McDonald.
Agnes Hamblen McDonald (1932- ) is a NC native of and a resident of Wilmington, NC. She received her Masters of Fine Arts degree from the University of North Carolina Wilmington. She is a member of the North Carolina Writer's Network, and is a poet and journal writer as well as short story author. Some of her poerty collections are in the New Hanover County Public Library
Agnes Geelan, Politician and Author
No full textAgnes Geelan was the first woman mayor of an incorporated city in the state, when she was elected mayor of Enderlin in 1946. She also had the honor of being the first woman state senator, when she served in the North Dakota Senate from 1951 to 1954. She was a member of the North Dakota Constitutional Convention in 1972 and also wrote The Dakota Maverick: the political life of William Langer, also known as Wild Bill in 1975.https://commons.und.edu/nd-politics-photos/1298/thumbnail.jp
The UN-SUSTAINABLE Match in HCV Recipients. Evidences from the Italian D-MELD Study on Balancing Donor-Recipient Risk Factors
No full textThe UN-SUSTAINABLE Match in HCV Recipients. Evidences from the Italian D-MELD Study on Balancing Donor-Recipient Risk Factor
Through Cyprus. by --- , author of Glimpses of greek life and scenery etc. Illustrated, with map
No full textAppendix.Dedication:Content description: Detailed contentsIllustration: (Maps ,Views ,portraits ,)Pagination: PP8+352PVolumes: 1Text Genre:ProseIllustration: (χάρτες ,τοπία ,πορτραίτα ,
Glimpses of greek life and scenery, by---, author of Eastern Pilgrims etc. etc.
No full textDedication:Content description: Detailed contentsIllustration: (Views ,portraits ,)Pagination: PP10+352PVolumes: 1Text Genre:ProseIllustration: (τοπία ,πορτραίτα ,
Multi-Beam LEO Satellite Beam Hopping Framework
No full text<h2>Multi-Beam LEO Satellite Beam Hopping Framework</h2>
<p>Python code to simulate multi-beam LEO satellite communication system with different beam hopping mechanisms.</p>
<p>With this Python code, the results from the paper can be reproduced and results with altered parameters can be produced and plotted. The code also contains the result data used to generate the figures in the journal paper.</p>
<h2>Technical details</h2>
<h3>Files</h3>
<ul>
<li><code>results</code> folder: contains simulation results saved as JSON files. New results are saved here if no other folder is specified. The saved result files are necessary to run <code>plotResults.py</code>.</li>
<li><code>simulation.py</code>: run simulations.</li>
<li><code>plotResults.py</code>: plot simulation results saved in results folder.</li>
<li><code>beamHoppingPattern.py</code>: implementation of beam hopping algorithms.</li>
<li><code>networkGeometry.py</code>: create satellite and user positions and set beam centers.</li>
<li><code>params.py</code> & <code>params.json</code>: simulation parameters.</li>
<li><code>channel.py</code>: functions related to the modeling of wireless transmission channel. Contains functions to calculate free space path loss, atmospheric loss, Rician fading, and array steering vector.</li>
<li><code>powerConsumption.py</code>: implementation of power consumption model.</li>
<li><code>precoder.py</code>: implementation of digital and analog precoder.</li>
<li><code>resourceAllocation.py</code>: cell association and user scheduling functions.</li>
<li><code>utils.py</code>: helper functions.</li>
<li>requirements.txt: requirements file to set up Python environment.</li>
</ul>
<h3>Required Packages</h3>
<p>The code has been tested with Python 3.12, the dependencies are listed in <code>requirements.txt</code>.<br>Here is a brief overview of the usage of the various libraries:</p>
<ul>
<li>JSON: save parameters and results in JSON files</li>
<li>NumPy: use of NumPy arrays for calculations</li>
<li>matplotlib.pyplot: plot results</li>
<li>itur: calculate atmospheric losses according to ITU recommendations</li>
<li>astropy.units: required for itur use</li>
<li>itertools: generate beam hopping patterns</li>
<li>scipy.stats: used to calculate confidence interval for solution plots</li>
<li>time: used to time the simulation duration</li>
</ul>
<h3>Additional Documentation</h3>
<p>The code was used to produce the results in:</p>
<pre>@ARTICLE{11137366,
author={Fastenbauer, Agnes and El Hadfi, Younes and Kaneko, Megumi and Svoboda, Philipp and Rupp, Markus},
journal={IEEE Open Journal of the Communications Society},
title={LEO Satellite Beam Hopping for Power Consumption Minimization at Different Elevation Angles},
year={2025},
volume={6},
pages={6930-6952},
doi={10.1109/OJCOMS.2025.3602090}}
<br>The paper shows and analyzes the simulation results.</pre>
<h2>How to Use</h2>
<h3>Run Simulation and Plot Results</h3>
<p>Run <code>simulation.py</code> to calculate and save simulation results.</p>
<p>Run <code>plotResults.py</code> to plot saved results.</p>
<h3>Change Simulation Parameters</h3>
<p>Use params.py to change simulation parameters such as:</p>
<ul>
<li>satellite altitude in <code>h_satellite</code></li>
<li>carrier frequency in <code>center_frequency</code></li>
<li>transmission bandwidth in <code>bandwidth_Hz</code></li>
<li>number of antenna elements per beam in <code>n_antenna_x </code>and <code>n_antenna_y</code></li>
<li>antenna array gain in <code>antenna_gain_dB</code></li>
<li>transmit power in <code>subband_transmit_power_W</code></li>
<li>receiver noise figure <code>noise_figure_dB</code></li>
</ul>
<p>The footprint size of the satellite serving area and the number of beams generated by the antenna array can be adjusted in the <code>simulation.py</code> file in the simulation functions by setting <code>r_footprint</code>, <code>n_beams</code>, <code>n_beams_x</code>, and <code>n_beams_y</code> to the desired footprint radius in meters.</p>
<h3>Use of Code</h3>
<p>When using code, please cite:</p>
<pre>@ARTICLE{11137366,
author={Fastenbauer, Agnes and El Hadfi, Younes and Kaneko, Megumi and Svoboda, Philipp and Rupp, Markus},
journal={IEEE Open Journal of the Communications Society},
title={LEO Satellite Beam Hopping for Power Consumption Minimization at Different Elevation Angles},
year={2025},
volume={6},
pages={6930-6952},
doi={10.1109/OJCOMS.2025.3602090}}</pre>
<h3>Licenses</h3>
<p>The code is licensed under MIT, the data is licensed under CC-BY.</p>
<h3>Acronyms</h3>
<p>ITU: International Telecommunications Union</p>
<p>LEO: Low Earth Orbit</p>
<p> </p>
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