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	<title>Comments on: If You Could See Cell Radio Signals</title>
	<atom:link href="http://www.epanorama.net/blog/2013/12/12/if-you-could-see-cell-radio-signals/feed/" rel="self" type="application/rss+xml" />
	<link>https://www.epanorama.net/blog/2013/12/12/if-you-could-see-cell-radio-signals/</link>
	<description>All about electronics and circuit design</description>
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		<title>By: Tomi Engdahl</title>
		<link>https://www.epanorama.net/blog/2013/12/12/if-you-could-see-cell-radio-signals/comment-page-1/#comment-1846594</link>
		<dc:creator><![CDATA[Tomi Engdahl]]></dc:creator>
		<pubDate>Tue, 18 Feb 2025 15:37:59 +0000</pubDate>
		<guid isPermaLink="false">http://www.epanorama.net/blog/?p=23647#comment-1846594</guid>
		<description><![CDATA[This ESP32 Antenna Array Can See WiFi 
https://www.youtube.com/watch?v=sXwDrcd1t-E

More information is available on the project website of the ESP32 antenna array &quot;ESPARGOS&quot;: https://espargos.net/

Source code for Python library + demos: https://github.com/ESPARGOS/pyespargos (directory &quot;demos/camera&quot; for &quot;WiFi camera&quot; demo)

As a research assistant at the Institute of Telecommunications at the University of Stuttgart, I work on multi-antenna systems like (distributed) massive MIMO, with a focus on wireless channel measurement platforms and algorithms for processing channel measurements (classical and deep learning-based).

One day, my (incredibly talented) colleague Marc Gauger suggested to use ultra low-cost ESP32 chips instead of software defined radios for channel measurements. I was highly sceptical at first, but when he showed me a minimalistic prototype he had soldered together, I was intrigued by the idea of being able to demonstrate my algorithms in real time using WiFi signals. In a series of Bachelor&#039;s / Research theses, my excellent students Tim Schneider, David Engelbrecht and David Kellner helped me develop the ESP32 antenna array &quot;ESPARGOS&quot;.

Measured CSI dataset used for AoA / TDoA visualization: https://espargos.net/datasets/data/es...
AoA / TDoA localization source code (needs some minor modifications to be applied to espargos-0005 dataset): https://github.com/Jeija/ToA-AoA-Augm...
Channel Charting source code for the animation in the video: https://github.com/Jeija/Geodesic-Unc...
Tutorial on Channel Charting: https://dichasus.inue.uni-stuttgart.d...

My research on (distributed) massive MIMO, Channel Charting and other algorithms for multi-antenna systems is funded by the German Federal Ministry of Education and Research (BMBF) within the project Open6GHub (grant no. 16KISK019).
I also want to express my gratitude towards ARENA2036, who hosted our measurement campaign for Channel Charting, and to my colleague and Channel Charting expert Phillip Stephan, with whom I co-authored several papers on Channel Charting and who assisted me with the creation of this video.]]></description>
		<content:encoded><![CDATA[<p>This ESP32 Antenna Array Can See WiFi<br />
<a href="https://www.youtube.com/watch?v=sXwDrcd1t-E" rel="nofollow">https://www.youtube.com/watch?v=sXwDrcd1t-E</a></p>
<p>More information is available on the project website of the ESP32 antenna array &#8220;ESPARGOS&#8221;: <a href="https://espargos.net/" rel="nofollow">https://espargos.net/</a></p>
<p>Source code for Python library + demos: <a href="https://github.com/ESPARGOS/pyespargos" rel="nofollow">https://github.com/ESPARGOS/pyespargos</a> (directory &#8220;demos/camera&#8221; for &#8220;WiFi camera&#8221; demo)</p>
<p>As a research assistant at the Institute of Telecommunications at the University of Stuttgart, I work on multi-antenna systems like (distributed) massive MIMO, with a focus on wireless channel measurement platforms and algorithms for processing channel measurements (classical and deep learning-based).</p>
<p>One day, my (incredibly talented) colleague Marc Gauger suggested to use ultra low-cost ESP32 chips instead of software defined radios for channel measurements. I was highly sceptical at first, but when he showed me a minimalistic prototype he had soldered together, I was intrigued by the idea of being able to demonstrate my algorithms in real time using WiFi signals. In a series of Bachelor&#8217;s / Research theses, my excellent students Tim Schneider, David Engelbrecht and David Kellner helped me develop the ESP32 antenna array &#8220;ESPARGOS&#8221;.</p>
<p>Measured CSI dataset used for AoA / TDoA visualization: <a href="https://espargos.net/datasets/data/es" rel="nofollow">https://espargos.net/datasets/data/es</a>&#8230;<br />
AoA / TDoA localization source code (needs some minor modifications to be applied to espargos-0005 dataset): <a href="https://github.com/Jeija/ToA-AoA-Augm" rel="nofollow">https://github.com/Jeija/ToA-AoA-Augm</a>&#8230;<br />
Channel Charting source code for the animation in the video: <a href="https://github.com/Jeija/Geodesic-Unc" rel="nofollow">https://github.com/Jeija/Geodesic-Unc</a>&#8230;<br />
Tutorial on Channel Charting: <a href="https://dichasus.inue.uni-stuttgart.d" rel="nofollow">https://dichasus.inue.uni-stuttgart.d</a>&#8230;</p>
<p>My research on (distributed) massive MIMO, Channel Charting and other algorithms for multi-antenna systems is funded by the German Federal Ministry of Education and Research (BMBF) within the project Open6GHub (grant no. 16KISK019).<br />
I also want to express my gratitude towards ARENA2036, who hosted our measurement campaign for Channel Charting, and to my colleague and Channel Charting expert Phillip Stephan, with whom I co-authored several papers on Channel Charting and who assisted me with the creation of this video.</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Tomi Engdahl</title>
		<link>https://www.epanorama.net/blog/2013/12/12/if-you-could-see-cell-radio-signals/comment-page-1/#comment-1044777</link>
		<dc:creator><![CDATA[Tomi Engdahl]]></dc:creator>
		<pubDate>Mon, 01 Sep 2014 11:30:19 +0000</pubDate>
		<guid isPermaLink="false">http://www.epanorama.net/blog/?p=23647#comment-1044777</guid>
		<description><![CDATA[One apartment’s Wi-Fi dead zones, mapped with a physics equation
A doctoral student does the math on where his Wi-Fi is, and isn&#039;t. 
http://arstechnica.com/gadgets/2014/08/mapping-wi-fi-dead-zones-with-physics-and-gifs/

A home&#039;s Wi-Fi dead zones are, to most of us, a problem solved with guesswork. Your laptop streams just fine in this corner of the bedroom, but not the adjacent one; this arm of the couch is great for uploading photos, but not the other one. You avoid these places, and where the Wi-Fi works becomes a factor in the wear patterns of your home. In an effort to better understand, and possibly eradicate, his Wi-Fi dead zones, one man took the hard way: he solved the Helmholtz equation.

The Helmholtz equation models &quot;the propagation of electronic waves&quot; that involves using a sparse matrix to help minimize the amount of calculation a computer has to do in order to figure out the paths and interferences of waves, in this case from a Wi-Fi router.

Cole writes that making the mapping simulation a Web service would probably be unfeasible due to the intensive calculations]]></description>
		<content:encoded><![CDATA[<p>One apartment’s Wi-Fi dead zones, mapped with a physics equation<br />
A doctoral student does the math on where his Wi-Fi is, and isn&#8217;t.<br />
<a href="http://arstechnica.com/gadgets/2014/08/mapping-wi-fi-dead-zones-with-physics-and-gifs/" rel="nofollow">http://arstechnica.com/gadgets/2014/08/mapping-wi-fi-dead-zones-with-physics-and-gifs/</a></p>
<p>A home&#8217;s Wi-Fi dead zones are, to most of us, a problem solved with guesswork. Your laptop streams just fine in this corner of the bedroom, but not the adjacent one; this arm of the couch is great for uploading photos, but not the other one. You avoid these places, and where the Wi-Fi works becomes a factor in the wear patterns of your home. In an effort to better understand, and possibly eradicate, his Wi-Fi dead zones, one man took the hard way: he solved the Helmholtz equation.</p>
<p>The Helmholtz equation models &#8220;the propagation of electronic waves&#8221; that involves using a sparse matrix to help minimize the amount of calculation a computer has to do in order to figure out the paths and interferences of waves, in this case from a Wi-Fi router.</p>
<p>Cole writes that making the mapping simulation a Web service would probably be unfeasible due to the intensive calculations</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: tomi</title>
		<link>https://www.epanorama.net/blog/2013/12/12/if-you-could-see-cell-radio-signals/comment-page-1/#comment-34733</link>
		<dc:creator><![CDATA[tomi]]></dc:creator>
		<pubDate>Fri, 13 Dec 2013 07:57:11 +0000</pubDate>
		<guid isPermaLink="false">http://www.epanorama.net/blog/?p=23647#comment-34733</guid>
		<description><![CDATA[Thank you for your feedback.
I will try to check that issue when I do some other updates on the site.]]></description>
		<content:encoded><![CDATA[<p>Thank you for your feedback.<br />
I will try to check that issue when I do some other updates on the site.</p>
]]></content:encoded>
	</item>
	<item>
		<title>By: Teukka</title>
		<link>https://www.epanorama.net/blog/2013/12/12/if-you-could-see-cell-radio-signals/comment-page-1/#comment-34732</link>
		<dc:creator><![CDATA[Teukka]]></dc:creator>
		<pubDate>Fri, 13 Dec 2013 06:46:06 +0000</pubDate>
		<guid isPermaLink="false">http://www.epanorama.net/blog/?p=23647#comment-34732</guid>
		<description><![CDATA[Your RSS feed seems to insert newlines at the start - meaning it breaks a number of browsers which want the &lt;?xml tag at the very beginning of  a file.]]></description>
		<content:encoded><![CDATA[<p>Your RSS feed seems to insert newlines at the start &#8211; meaning it breaks a number of browsers which want the &lt;?xml tag at the very beginning of  a file.</p>
]]></content:encoded>
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