<span style=" font-size:10pt;font-family:sans-serif">Dear All, </span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">Thanks a lot to
Dirk and Géraldine for the very useful contribution.</span>
<br><span style=" font-size:10pt;font-family:sans-serif">In the past we
used the "ampère model" (in slide 7 from Géraldine), and, as
Géraldine correctly pointed out, it's just a matter of scaling to move
from that to the "photons per bit model" (slide 8). So for ESA
it's fine either way.</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">I think that the
last details that we need to agree upon before running the new simulation
campaign concern the fading and the interleaver dimensioning. In our opinion
it is important to include them both in the assessment, since in past meetings
it was shown that there is an intertwined relationship between the code,
the channel, and the interleaver. </span>
<br><span style=" font-size:10pt;font-family:sans-serif">For simplicity
we propose to use fading A from the DLR, leaving the performance assessment
with the other time series for the green book. On the interleaver dimensioning,
since it depends both on the symbol rate and the fading, I think that we
should pick 3 different (N,B) values. Honestly, I don't think we have the
time (nor the need) for an accurate optimization of these parameters, so
we might well live with a rule-of-thumb dimensioning.</span>
<br>
<br><span style=" font-size:10pt;font-family:sans-serif">Finally, concerning
Géraldine's request for the mutual information, we still don't think that
such investigation would be worth the required effort. This applies in
particular to fading channels, where the computation of the mutual information
is not as straightforward as on the AWGN channel, especially when the fading
is not generated according to a given statistical model but numerically
by means of a time series. Also, including the interleaver would further
complicate the analysis. On top of this, we are not using Matlab for our
simulations, and including the mutual information in our simulator would
inevitably delay the delivery of the results of the new simulation campaign.</span>
<br><span style=" font-size:10pt;font-family:sans-serif"><br>
Kind regards,</span>
<br>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:8pt;color:#808080;font-family:Verdana"><b>Modis
for ESA - European Space Agency</b></span><span style=" font-size:12pt;font-family:Tms Rmn">
</span><span style=" font-size:8pt;color:#00a1e0;font-family:Verdana"><br>
<br>
Nicolò Mazzali, PhD </span><span style=" font-size:8pt;color:#808080;font-family:Verdana"><br>
Communication Systems & Technologies Engineer</span><span style=" font-size:12pt;font-family:Tms Rmn">
</span><span style=" font-size:8pt;color:#808080;font-family:Verdana"><br>
<br>
Telecommunications Section (TEC-ESC)</span><span style=" font-size:12pt;font-family:Tms Rmn">
</span><span style=" font-size:8pt;color:#808080;font-family:Verdana"><br>
Radio Frequency Systems Division (TEC-ES)</span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:8pt;color:#808080;font-family:Verdana">Directorate
of Technology, Engineering & Quality (D/TEC)<b><br>
<br>
<br>
ESTEC</b><br>
Keplerlaan 1, PO Box 299<br>
NL-2200 AG Noordwijk, The Netherlands</span><span style=" font-size:8pt;color:#0082bf;font-family:Verdana"><u><br>
</u></span><a href=mailto:nicolo.mazzali@esa.int><span style=" font-size:8pt;color:#0082bf;font-family:Verdana"><u>nicolo.mazzali@esa.int</u></span></a><span style=" font-size:8pt;color:#808080;font-family:Verdana">
| </span><a href=http://www.esa.int/><span style=" font-size:8pt;color:#8f8f8f;font-family:Verdana"><u>www.esa.int</u></span></a><span style=" font-size:8pt;color:#808080;font-family:Verdana"><br>
T +31 71 56 53215</span></p>
<br>
<br>
<br>
<br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">From:
       </span><span style=" font-size:9pt;font-family:sans-serif"><Dirk.Giggenbach@dlr.de></span>
<br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">To:
       </span><span style=" font-size:9pt;font-family:sans-serif"><Jon.Hamkins@jpl.caltech.edu></span>
<br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">Cc:
       </span><span style=" font-size:9pt;font-family:sans-serif">SLS-OPT@mailman.ccsds.org</span>
<br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">Date:
       </span><span style=" font-size:9pt;font-family:sans-serif">23/04/2020
20:04</span>
<br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">Subject:
       </span><span style=" font-size:9pt;font-family:sans-serif">Re:
[SLS-OPT] O3K channel model</span>
<br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">Sent
by:        </span><span style=" font-size:9pt;font-family:sans-serif">"SLS-OPT"
<sls-opt-bounces@mailman.ccsds.org></span>
<br>
<hr noshade>
<br>
<br>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri">Hi
Jon,</span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri"> </span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri">we
do not have data APD-RFEs for that low rate which we could test/measure.</span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri">I
checked some datasheets, the one coming closest to 1.22Mbps is the LaserComponents
IAG350H1D –APD Receiver with 1MHz Bandwidth and 350µm APD.  They
don’t show dark current in the DS.</span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri"><br>
These values seem close to best compared to other receivers:</span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri">Responsivity=94MV/W
 ,  I guess that includes Amplification of M=10, so TIA would
be ~9MOhm </span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri">NEP=32fW/sqrt(Hz)
  -   referred noise density of 0.3E-12 A/sqrt(Hz)  or  3µV/sqrt(Hz)
 </span></p>
<p style="margin-top:0px;margin-Bottom:0px"><a href="https://www.lasercomponents.com/de-en/product/apd-receivers/"><span style=" font-size:11pt;color:blue;font-family:Calibri"><u>https://www.lasercomponents.com/de-en/product/apd-receivers/</u></span></a><span style=" font-size:11pt;color:#004080;font-family:Calibri">
</span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri"> </span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri">Hope
that helps,</span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri"> </span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri">Dirk</span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri"> </span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:11pt;color:#004080;font-family:Calibri"> </span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:12pt;font-family:Times New Roman"> </span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:10pt;font-family:Tahoma"><b>Von:</b>
SLS-OPT [</span><a href="mailto:sls-opt-bounces@mailman.ccsds.org"><span style=" font-size:10pt;font-family:Tahoma">mailto:sls-opt-bounces@mailman.ccsds.org</span></a><span style=" font-size:10pt;font-family:Tahoma">]
<b>Im Auftrag von </b>Jon Hamkins via SLS-OPT<b><br>
Gesendet:</b> Mittwoch, 15. April 2020 17:20<b><br>
An:</b> SLS-OPT@mailman.ccsds.org<b><br>
Betreff:</b> [SLS-OPT] O3K channel model</span></p>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:12pt;font-family:Times New Roman"> </span></p>
<br><span style=" font-size:12pt;font-family:Times New Roman">Attached
is the O3K channel model we discussed yesterday.  It also contains
a suggestion for how to state the O3K coding performance.  I welcome
your comments.  If we can agree to the model in the next week or so,
each agency may be able to begin simulating with it and discuss some initial
results at the May teleconferences.</span>
<br><span style=" font-size:12pt;font-family:Times New Roman">A few notes:</span>
<ul>
<li><span style=" font-size:12pt;font-family:Times New Roman">I am suggesting
we study 10 Gsps, 78.125 Msps, and 1.22 Mbps, since those include the highest
and lowest data rates and one in the middle.</span>
<li><span style=" font-size:12pt;font-family:Times New Roman">I don't have
a good suggestion for the TIA noise density at 1.22 Msps.  Dirk, would
you be able to supply a number?</span>
<li><span style=" font-size:12pt;font-family:Times New Roman">I have algebraically
simplified the expressions for the means and variances.  You can compare
the model to the expressions Dariush presented on yesterday (p. 5), and
check my algebra.</span>
<li><span style=" font-size:12pt;font-family:Times New Roman">I have included
the fading parameter as well.  Just set rho=1 if you want no fading.</span></ul><span style=" font-size:12pt;font-family:Times New Roman"> 
   ----Jon</span>
<p style="margin-top:0px;margin-Bottom:0px"><span style=" font-size:12pt;font-family:Times New Roman">--
<b><br>
Jon Hamkins</b><br>
Lead Technologist<br>
33   |   Communications, Tracking, and Radar Division<b><br>
O</b> 818-354-4764   |   <b>M</b> 626-658-6220 <br>
<b><br>
JPL</b>   |   jpl.nasa.gov </span></p>
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</PRE>