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<p class="MsoNormal">I’m not a patent expert but it appears the first one listed covers the generation of spread spectrum “chirps” using a fractional N synthesizer. The other patent covers the data formatting and modulation scheme. Assuming we have to stay
away from those two aspects, we could still use chirp spread spectrum, just not generated the same way. The biggest advantage to chirped spread spectrum from a satellite operations perspective is that it’s inherently resistant to doppler issues. As long as
the signal is in the receiver bandwidth and you can detect the direction of the chirp you can decode the signal. Using a chirp spread spectrum physical layer into a an adapted 802.16 mesh network configuration could provide a way to have satellite augmented
ground networks (or vice versa) without having to have a planned constellation of satellites. If every new LEO carried the transponder, the network would automatically form and grow. When satellites are visible to each other traffic would also be repeated
satellite to satellite. If the frequency plan was compatible to QO-100 transatlantic relays could be possible into the QO-100 footprint.
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<p class="MsoNormal">Howie AB2S</p>
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<p class="MsoNormal" style="border:none;padding:0in"><b>From: </b><a href="mailto:ground-station@lists.openresearch.institute">Bruce Perens via Ground-Station</a><br>
<b>Sent: </b>Wednesday, March 31, 2021 7:13 PM<br>
<b>To: </b><a href="mailto:dquagliana@gmail.com">Douglas Quagliana</a><br>
<b>Cc: </b><a href="mailto:ground-station@lists.openresearch.institute">Michelle Thompson via Ground-Station</a><br>
<b>Subject: </b>Re: [Ground-station] Question for ORI:</p>
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<p class="MsoNormal">On Wed, Mar 31, 2021 at 3:43 PM Douglas Quagliana <<a href="mailto:dquagliana@gmail.com">dquagliana@gmail.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">Bruce writes:<o:p></o:p></p>
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<p class="MsoNormal">> someone more skilled than me would be sitting down to make an open data link implementation built on some cheap microprocessor
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<p class="MsoNormal">If I understand what you're saying, Phil has already written several downlink schemes.<o:p></o:p></p>
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<p class="MsoNormal">Yes, but I am not aware of Phil addressing this particular application, which is dirt-cheap SS data links between so-far-terrestrial embedded microprocessors with a link budget to go miles at the lowest data rate and long life on small
batteries. I hold out some hope that the functionality of their chip can be duplicated with a relatively small number of discrete components and a cheap microprocessor. Certainly we have ones that can do significant DSP in the $4 range these days, and they
idle at microamps drain.<o:p></o:p></p>
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<p class="MsoNormal"> Thanks<o:p></o:p></p>
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<p class="MsoNormal"> Bruce<o:p></o:p></p>
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