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Hi all,<br>
<br>
Its a long long time since I posted any messages here but I've been
monitoring the list. Over the last several months I've been
building, for my amusement, a server process for HPSDR. I've chosen
Google Go for the development and must say I'm finding it pretty
good. However, I've deliberately backed myself into a corner where I
need to develop a complete DSP processing chain in order to take
full advantage of my architecture. Now DSP is a pretty weak point
with me but I'm determined to master it this time around. I
understand some of the principals but am missing a lot of detail in
going from principals to code. SharpDSP is a good model for me to
follow but I don't want to blindly translate the code without
understanding what I'm doing.<br>
<br>
Finally, the questions. <br>
<ol>
<li>Is there a write up at a block level of SharpDSP because I'm
not sure why blocks are ordered as they are. The purpose of most
is obvious but I'm a bit confused by the oscillator block which
I guess is converting to baseband(?). <br>
</li>
<li>Demodulation is something I don't fully get. I believe the
convolution directly demodulates CW/SSB (and from what I
remember can convert to baseband as well) but for other modes
demod is tacked on the end of the processing.</li>
<li>When doing the overlap/add method of fast convolution I don't
know how one calculates how big the FFT should be or how many
taps the filter should have in relation to the sample block size
and what the effect of the choice is. Should a small block size
(for reduced latency) have a smaller FFT? I've not found a
really good algorithm that explains this and many I found seem
to differ in approach so I'm not clear on the correct
implementation.</li>
</ol>
<p>Any pointers appreciated.<br>
</p>
<p>Bob (G3UKB)<br>
</p>
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