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Amen<br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Ground-Station <ground-station-bounces@lists.openresearch.institute> on behalf of Wally Ritchie via Ground-Station <ground-station@lists.openresearch.institute><br>
<b>Sent:</b> Saturday, August 24, 2019 9:42:22 AM<br>
<b>To:</b> KC9SGV <kc9sgv@gmail.com><br>
<b>Cc:</b> Ground Station <ground-station@lists.openresearch.institute><br>
<b>Subject:</b> Re: [Ground-station] DVB-S2 or -X bandwidth ?</font>
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<div dir="ltr">A 1 MHz wide DVB-S2 signal supports a symbol rate of 800k symbols per second. This is sufficient to carry a virtually error-free transport a payload of a few megabits per second. In terms of communication quality digitized speech, we need a net
payload of 1600 - 2400 bits per second per channel. So 1 megabit of net payload is equivalent to more than 400 communication quality voice channels (i.e. better than ssb) or roughly the equivalent of all of the 80,40,20, and 15 bands.
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<div>The whole idea here is that we are using state of the art digital technologies to transport all of the received uplink channels into a single downlink carrier. The purpose of the commercial testbed channel is to provide an environment for testing the digital
DOWNLINK. There will be no analog signals - only digital. The transponder will be combining (or multiplexing) a large number of narrowband digital uplinks into a single downlink. </div>
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<div>Forget analog modes. There is absolutely zero place for analog modulations. Any analog modes will be converted to digital on the ground. </div>
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<div>WU1Y</div>
<div>Wally</div>
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<div dir="ltr" class="gmail_attr">On Sat, Aug 24, 2019 at 8:55 AM KC9SGV via Ground-Station <ground-station@lists.openresearch.institute> wrote:<br>
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<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Hi All, <br>
Is 1 MHz wide enough for DVB-S2 transmissions ?<br>
I cannot attach a picture here, but look on page 17 of this old TAPR paper.<br>
Seems like 2 MHz is the minimum bandwidth required ?<br>
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<a href="https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.tapr.org%2Fpdf%2FDCC2009-DATV-KB6CJZ-W6HHC.pdf&data=02%7C01%7C%7Cf9206cb4dddf433fab0208d72899a6d7%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637022512696710320&sdata=rvaOxePa2pCMAUkbKXH6z33nMvCs3MFKUmXHt16AE0s%3D&reserved=0" originalsrc="https://www.tapr.org/pdf/DCC2009-DATV-KB6CJZ-W6HHC.pdf" shash="nUPQVXlw63th+Is9D2o6uh/xbIbdsNicxxuWREhwSZvPhqo439ImN8JwdL8Wsmlpyyly6sIKMgo99FBcG0usoyB69jjSOr01+Sbx9dDo7QgSs0QQvJLC84SeeOK+H9rb0CStmNKj0dAjsf6oPVYf6pPMvDwbufaJ412b+T/Mnx0=" rel="noreferrer" target="_blank">https://www.tapr.org/pdf/DCC2009-DATV-KB6CJZ-W6HHC.pdf</a><br>
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Maybe only legacy ham Linear modes will be supported by our 1 MHz Rent-a- GEO effort ?<br>
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Bernard,<br>
KC9SGV<br>
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Sent from my iPad<br>
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