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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Now I finally understand the “Bill Tracey may have been
here” comments salted into the PowerSDR codebase….<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:Wingdings;
color:#1F497D'>J</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Dan<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
hpsdr-bounces@lists.openhpsdr.org [mailto:hpsdr-bounces@lists.openhpsdr.org] <b>On
Behalf Of </b>Frank Brickle<br>
<b>Sent:</b> Monday, June 08, 2009 4:36 PM<br>
<b>To:</b> David McQuate<br>
<b>Cc:</b> hpsdr@openhpsdr.org<br>
<b>Subject:</b> Re: [hpsdr] spectrum increased frequency resolution?<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal style='margin-bottom:12.0pt'>Stuff the samples into a longer
FFT and pad with zeros.<br>
<br>
Remember, though, that what you gain in frequency resolution you lose in time
resolution. That's Heisenberg Uncertainty.<br>
<br>
You also have to be a little careful about how you window the data. Google is
your friend.<br>
<br>
73<br>
Frank<br>
AB2KT<o:p></o:p></p>
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<p class=MsoNormal>On Mon, Jun 8, 2009 at 5:57 PM, David McQuate <<a
href="mailto:mcquate@sonic.net">mcquate@sonic.net</a>> wrote:<o:p></o:p></p>
<p class=MsoNormal>***** High Performance Software Defined Radio Discussion
List *****<br>
<br>
If I have a block of samples (say N = 4096, fs = 122.88 Msps),<br>
a straightforward FFT produces data with frequency resolution of 30kHz.<br>
<br>
Is there a technique that will allow me to obtain information on a finer<br>
frequency grid (say 1kHz or 300Hz or ...)--other than "simply"
acquiring<br>
additional data, extending the length of the time record?<br>
<br>
I've looked at Chirp-Z transforms and polyphase decimation, but neither<br>
seems to produce higher frequency resolution. I've also looked into
DttSP,<br>
but not found a solution there.<br>
<br>
Am I hoping for the impossible?<br>
<br>
Suggestions please.<br>
<br>
73,<br>
Dave<br>
wa8ywq<br>
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<p class=MsoNormal><br>
<br clear=all>
<br>
-- <br>
...although production beyond capacity is a contradiction in terms, it is
observed every day in academia. -- Frank Knight<o:p></o:p></p>
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