<html><head></head><body><div class="ydp9b979792yahoo-style-wrap"><div style="font-size: 13px; font-family: Helvetica Neue, Helvetica, Arial, sans-serif;"></div>
<div><font size="2">M - I'm hearing pieces of the puzzle.<br></font></div><div><font size="2"><br></font></div><div><font size="2">Ron is stating the standard is 950-2150 for DVB-S2; yet clearly others are putting a lower IF into an SDR (with integrated FPGA).</font></div><div><font size="2"><br></font></div><div><font size="2">I also understood some folks are working on a discrete FPGA (or Nvidia??) chip, with TBD front end. </font></div><div><font size="2">I believe my decimation questions started with that paradigm, but not necessarily limited to that scope. </font></div><div><span style="font-size: small;">So can we get the DVB "standard" to work with lower IF's? (ie, 144, 618, 700ish MHz) </span><br></div><div><font size="2"><br></font></div><div><font size="2">It makes sense an Off-The-Shelf wideband SDR can just absorb the data directly. (My impression is we needed more horse power for the DSP backend.)</font></div><div><font size="2"><br></font></div><div><font size="2">As for LNB's, I didn't realize some were stable enough for 10G links.</font></div><div><font size="2">I believe the North Amer. Ph4B design target design is Geostationary, so a few Hz may matter. (I'm still trying to guess what a EsHal bird is?) </font></div><div style="font-size: 13px; font-family: Helvetica Neue, Helvetica, Arial, sans-serif;">If a dish is too narrow to target, a some of us have 10G Flat Panels with ~7-8 degree beam width.</div><div style="font-size: 13px; font-family: Helvetica Neue, Helvetica, Arial, sans-serif;"> </div><div style="font-size: 13px; font-family: Helvetica Neue, Helvetica, Arial, sans-serif;">It sounds like there are several sub-projects and many variations in hardware implementations; constraints in one may not apply to another.</div><div style="font-size: 13px; font-family: Helvetica Neue, Helvetica, Arial, sans-serif;"><br></div><div style="font-size: 13px; font-family: Helvetica Neue, Helvetica, Arial, sans-serif;">Keep the comments coming...</div><div style="font-size: 13px; font-family: Helvetica Neue, Helvetica, Arial, sans-serif;"><br></div><div style="font-size: 13px; font-family: Helvetica Neue, Helvetica, Arial, sans-serif;">regards,</div><div style="font-size: 13px; font-family: Helvetica Neue, Helvetica, Arial, sans-serif;">KI6CLA</div><div style="font-size: 13px; font-family: Helvetica Neue, Helvetica, Arial, sans-serif;"><br></div><div style="font-size: 13px; font-family: Helvetica Neue, Helvetica, Arial, sans-serif;"><br></div>
</div><div id="ydpa503dcbfyahoo_quoted_9435343574" class="ydpa503dcbfyahoo_quoted">
<div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;">
<div>
On Friday, January 25, 2019, 4:09:21 PM PST, Michelle Thompson via Ground-Station <ground-station@lists.openresearch.institute> wrote:
</div>
<div><br></div>
<div><br></div>
<div><div id="ydpa503dcbfyiv3036508083"><div><div dir="ltr">The beginning of wisdom being the definition of terms and all, it would be good to make sure we're all talking about the same thing. <br clear="none"><br clear="none">So far, I've used LNBs and USRPs for receive, with the LNB doing an IF at 618MHz (LNB-on-a-Stick) and giving reasonable performance. <br clear="none"><br clear="none">Decimation to me is a DSP thing, or used to reduce power consumption when you don't need to sample as high as you can. <br clear="none"><br clear="all"><div><div class="ydpa503dcbfyiv3036508083gmail_signature" dir="ltr"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr">-Michelle W5NYV<br clear="none"><br clear="none"><div dir="ltr"><br clear="none"></div></div></div></div></div></div></div></div></div><br clear="none"></div><br clear="none"><div class="ydpa503dcbfyiv3036508083gmail_quote"><div class="ydpa503dcbfyiv3036508083yqt7651904491" id="ydpa503dcbfyiv3036508083yqt27358"><div class="ydpa503dcbfyiv3036508083gmail_attr" dir="ltr">On Fri, Jan 25, 2019 at 3:52 PM Ron Economos via Ground-Station <ground-station@lists.openresearch.institute> wrote:<br clear="none"></div><blockquote class="ydpa503dcbfyiv3036508083gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex;">
<div>
<p>The standard IF for DVB-S2 receivers is 950 to 2150 MHz.</p>
<p>DB6NT was selling a down-converter from 10489-10500 MHz to
1129-1140 MHz for P4A.</p>
<p><a shape="rect" class="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776moz-txt-link-freetext" href="https://shop.kuhne-electronic.com/kuhne/en/shop/new/MKU+LNC+10+OSCAR+P4A/?card=1832" rel="nofollow" target="_blank">https://shop.kuhne-electronic.com/kuhne/en/shop/new/MKU+LNC+10+OSCAR+P4A/?card=1832</a></p>
<p>I'm not sure what decimation has to do with receiving DVB-S2. The
entire 10 MHz signal needs to be demodulated. Individual baseband
frames will be selected for processing, but I call that
de-multiplexing.<br clear="none">
</p>
<p>Ron W6RZ<br clear="none">
</p>
<div class="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776moz-cite-prefix">On 1/25/19 15:32, David Vieira via
Ground-Station wrote:<br clear="none">
</div>
<blockquote type="cite">
<div class="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776ydp1f38d99eyahoo-style-wrap">
<div>Michelle - Thanks for posting. I'll frame some of the
questions.<br clear="none">
</div>
<div><br clear="none">
</div>
<div>Typical 10 GHz terrestrial contesting rigs are Heterodyne;
that is a Mixer works with a Local Oscillator (LO) to take the
RF down to an IF (Intermediate Frequency).</div>
<div>For an SDR, that IF can be digitized by an Analog-Digital
Converter.</div>
<div><br clear="none">
</div>
<div>The most popular IF for contesting/SSB rigs is 144 MHz. </div>
<div>For a data BW of 10 MHz that may or may not be a fast
enough IF carrier. If we can digitize and recover the data,
it would allow a lot of re-use of existing equipment.</div>
<div><br clear="none">
</div>
<div>I've heard suggestions/proposals up to the 1.2 GHz Ham
band.</div>
<div>In some sense, the IF carrier could be 144/220/440/915/1200
MHz, or even any Non-Ham frequency in between.</div>
<div><br clear="none">
</div>
<div>There are a lot of proof of existence designs for a 10 GHz
Mixed down to an IF; and lots of off the shelf ADC
dev-boards. (catch me off thread for details).</div>
<div><br clear="none">
</div>
<div>Some questions I have are: </div>
<div>---from an FPGA side of the SDR, what data rate(s) can the
FPGA absorb in to a decimator? </div>
<div><br clear="none">
</div>
<div>Must we decide upfront on a single frequency; or </div>
<div>preferably allow flexibility in the RF front end design
(ie, Mixer, PLL and Local Oscl hardware choices) by allowing a
wide and programmable variety of ADC and decimation rates?</div>
<div><br clear="none">
</div>
<div>{This is where RF and Digital folks must communicate across
walls.} ;-)</div>
<div><br clear="none">
</div>
<div>Comments welcome.</div>
<div><br clear="none">
</div>
<div>regards,</div>
<div>David</div>
<div>KI6CLA</div>
<div><br clear="none">
</div>
<div><br clear="none">
</div>
</div>
<div class="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776ydp40e62e6byahoo_quoted" id="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776ydp40e62e6byahoo_quoted_8708381549">
<div>
<div> On Friday, January 25, 2019, 2:41:54 PM PST, Michelle
Thompson via Ground-Station
<a shape="rect" class="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776moz-txt-link-rfc2396E" href="mailto:ground-station@lists.openresearch.institute" rel="nofollow" target="_blank"><ground-station@lists.openresearch.institute></a> wrote: </div>
<div><br clear="none">
</div>
<div><br clear="none">
</div>
<div>
<div id="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776ydp40e62e6byiv6388574106">
<div dir="ltr">
<div dir="ltr">While we are striving to enable all sorts
of wonderful designs by putting prototypes into GNU
Radio, a central goal is to design our own hardware.<br clear="none">
<br clear="none">
We've had a lot of progress on the protocol and
algorithm front (GSE, LDPC, some of the polyphase). <br clear="none">
<br clear="none">
Some fundamental decisions about our own hardware need
to be made.<br clear="none">
<br clear="none">
When we receive, we expect to have to decimate. This
is because we are receiving at a relatively high
frequency (10GHz).<br clear="none">
<br clear="none">
Our bandwidth is (up to) 10MHz. For DVB-S2/X, we fix
our sampling rate, depending on what bandwidth we want
to support. We have a lot of freedom here.<br clear="none">
<br clear="none">
Picking the right frequencies for the receive chain is
therefore important.<br clear="none">
<br clear="none">
What are our options? <br clear="none">
<br clear="none">
What options make the best sense?<br clear="none">
<br clear="none">
I'd like to build and test as soon as possible, so
let's get some discussion going.<br clear="none">
<br clear="none">
<div>
<div class="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776ydp40e62e6byiv6388574106gmail_signature" dir="ltr">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div dir="ltr">-Michelle W5NYV<br clear="none">
<br clear="none">
<div dir="ltr"><br clear="none">
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
_______________________________________________<br clear="none">
Ground-Station mailing list<br clear="none">
<a shape="rect" href="mailto:Ground-Station@lists.openresearch.institute" rel="nofollow" target="_blank">Ground-Station@lists.openresearch.institute</a><br clear="none">
<a shape="rect" href="http://lists.openresearch.institute/mailman/listinfo/ground-station" rel="nofollow" target="_blank">http://lists.openresearch.institute/mailman/listinfo/ground-station</a><br clear="none">
</div>
</div>
</div>
<br clear="none">
<fieldset class="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776mimeAttachmentHeader"></fieldset>
<pre class="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776moz-quote-pre">_______________________________________________
Ground-Station mailing list
<a shape="rect" class="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776moz-txt-link-abbreviated" href="mailto:Ground-Station@lists.openresearch.institute" rel="nofollow" target="_blank">Ground-Station@lists.openresearch.institute</a>
<a shape="rect" class="ydpa503dcbfyiv3036508083gmail-m_-6643074664132559776moz-txt-link-freetext" href="http://lists.openresearch.institute/mailman/listinfo/ground-station" rel="nofollow" target="_blank">http://lists.openresearch.institute/mailman/listinfo/ground-station</a>
</pre>
</blockquote>
</div>
_______________________________________________<br clear="none">
Ground-Station mailing list<br clear="none">
Ground-Station@lists.openresearch.institute<br clear="none">
<a shape="rect" href="http://lists.openresearch.institute/mailman/listinfo/ground-station" rel="nofollow" target="_blank">http://lists.openresearch.institute/mailman/listinfo/ground-station</a><br clear="none">
</blockquote></div></div></div></div><div class="ydpa503dcbfyqt7651904491" id="ydpa503dcbfyqt29838">_______________________________________________<br clear="none">Ground-Station mailing list<br clear="none"><a shape="rect" href="mailto:Ground-Station@lists.openresearch.institute" rel="nofollow" target="_blank">Ground-Station@lists.openresearch.institute</a><br clear="none"><a shape="rect" href="http://lists.openresearch.institute/mailman/listinfo/ground-station" rel="nofollow" target="_blank">http://lists.openresearch.institute/mailman/listinfo/ground-station</a><br clear="none"></div></div>
</div>
</div></body></html>