{"id":364,"date":"2011-10-12T13:29:42","date_gmt":"2011-10-12T13:29:42","guid":{"rendered":"http:\/\/gswce.net\/?page_id=364"},"modified":"2016-03-15T08:48:16","modified_gmt":"2016-03-15T08:48:16","slug":"communication-physical-layers","status":"publish","type":"page","link":"https:\/\/gswce.net\/?page_id=364","title":{"rendered":"Communication Physical Layers"},"content":{"rendered":"

<\/a>This page currently hosts the demos about the physical layers of electronics. There’s another couple of these in the works (radio receiver designs) but I don’t teach this material any more, so more demos are likely to be written on request. Any ideas, please let me know.<\/p>\n

Click on the title or the picture to get the full demo.<\/p>\n\n\n\n
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Baseband Modulation Demo<\/h3>\n

I hope this one will be self-explanatory, or at least simple to work out by just pressing the buttons and seeing what they do. The reason you can turn the power spectrum on and off is to play guessing games in lectures \u201cwhat will the spectrum of this one look like?\u201d and so on.<\/td>\n

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\nVideo instructions and demo coming soon…
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Cellular Interference Demo<\/h3>\n

In the absence of any instructions (yet), probably best to play around with this one. It plots the CNIR of nodes in an ideal hexagonal cellular system.<\/td>\n

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\nVideo instructions and demo coming soon…
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Equivalent Baseband Demo<\/h3>\n

Demonstrates the idea of the equivalent baseband, what equivalent baseband noise looks like, and how simple modulation schemes work in the equivalent baseband. Real-time mode reflects the last five seconds in the movement of the equivalent baseband signal (click on and drag the blue circle around to see what it does). Non-real time mode is a bit more realistic.<\/td>\n

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\nVideo instructions and demo coming soon…
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Linear Passband Modulation Demo<\/h3>\n

Another one which really needs some better instructions\u2026 for now note you can drag the constellation points around, and the persistance button plots a sort of scatter diagram. Symbol errors are in red, and the plots can be done in either Eb\/N0 or Es\/N0. Used to run some graphs, and then show that the theory actually works.<\/td>\n

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\nVideo instructions and demo coming soon…
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Mobile Channels Demo<\/h3>\n

Double-click anywhere in the axes to add a ray, then drag them around to change the delay and power of that ray. Switching on Rayleigh fading will change the amplitude and phase of the rays. The three coloured lines represent the three chosen definitions of coherence bandwidth; you can drag them over the spectrum to illustrate how fast the frequencies change.<\/td>\n

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\nVideo instructions and demo coming soon…
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Passband Modulation Schemes Demo<\/h3>\n

Similar to the baseband modulation, but for passband modulation schemes. A couple of the controls differ: the slider in the middle of the screen changes the carrier frequency, and the checkbox in the top-left of the square box to the bottom-left switches to a 3D view mode \u2013 try dragging the mouse around in this box in 3D mode. Also, double-clicking on the slider in pause mode automates the sweep.<\/td>\n

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\nVideo instructions and demo coming soon…
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Polarisation Demo<\/h3>\n

Demo to show vertical, horizontal and circular polarisation by showing them in a 3D plot, and allowing various combinations of the polarisations to be combined. Mostly obvious controls I hope, except to manipulate the 3D view:<\/p>\n

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  • Drag mouse with left button pressed to change point of view direction<\/li>\n
  • Drag mouse with right button pressed to move laterally<\/li>\n
  • Double click left mouse button to return to default view<\/li>\n
  • You can double-click a slider to return the value to the default<\/li>\n<\/ul>\n

    Note that more distant objects are in muted colours. I\u2019m rather pleased with the effect.<\/td>\n

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\nVideo instructions and demo coming soon…
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Rayleigh Fading and the Central Limit Theorem Demo<\/h3>\n

Similar to the baseband modulation, but for passband modulation schemes. A couple of the controls differ: the slider in the middle of the screen changes the carrier frequency, and the checkbox in the top-left of the square box to the bottom-left switches to a 3D view mode \u2013 try dragging the mouse around in this box in 3D mode. Also, double-clicking on the slider in pause mode automates the sweep.<\/td>\n

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\nVideo instructions and demo coming soon…
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Refraction Demo<\/h3>\n

\u201cShort Links\u201d ignores the curvature of the Earth. Note that this not to scale: the vertical dimension is greatly exaggerated. To make the antennas different heights double-click on the antenna height slider (and the green linking bar will disappear; double-click again and it\u2019ll come back to set the antennas at equal heights again).<\/td>\n

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\nVideo instructions and demo coming soon…
\nBack to top<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

This page currently hosts the demos about the physical layers of electronics. There’s another couple of these in the works (radio receiver designs) but I don’t teach this material any more, so more demos are likely to be written on … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":122,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"_links":{"self":[{"href":"https:\/\/gswce.net\/index.php?rest_route=\/wp\/v2\/pages\/364"}],"collection":[{"href":"https:\/\/gswce.net\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/gswce.net\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/gswce.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gswce.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=364"}],"version-history":[{"count":23,"href":"https:\/\/gswce.net\/index.php?rest_route=\/wp\/v2\/pages\/364\/revisions"}],"predecessor-version":[{"id":805,"href":"https:\/\/gswce.net\/index.php?rest_route=\/wp\/v2\/pages\/364\/revisions\/805"}],"up":[{"embeddable":true,"href":"https:\/\/gswce.net\/index.php?rest_route=\/wp\/v2\/pages\/122"}],"wp:attachment":[{"href":"https:\/\/gswce.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=364"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}