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GNU Radio minimum sample rate [zedboard/fmcomms3]

Question asked by vshn on Mar 9, 2016
Latest reply on Mar 10, 2016 by larsc

Hello,

 

Im trying to implement a design with the minimum sampling rate in GNU radio. By looking at this forum post it looks like I can sample at 233 ksps as long as I do max interpolation/decimation at the sink/source stages. I am certainly over simplifying the problem though.

 

I set the FMComms2 Sink to -->

 

Sample Rate: 233ksps

Interpolation: 48

 

Which should bring the effective sample rate up to 1.536Msps. When I run this configuration I receive the errors:

 

unable to set samplerate (-22)

unable to set attenuation (-22)

unable to set attenuation (-22)

 

Is the problem that I am not specifically setting the programmable tx filter? Find attached an image of the qpsk modulator transmission side I'm testing with.

 

I realize the attenuation error is separate but I'm also not able to determine what is causing those - I am using the standard 10 dB attenuation value.

 

Thanks.

 

[img]http://i.imgur.com/X5YZr5D.jpg[/img]


edit:


I was doing something silly earlier. Interpolation should only be 7 to up the sample rate to > 1.536 msps. If I set the Sample Rate to 233E3 * 7 the error goes away. This happens regardless if I set the interpolation field to 1 or 7 or anything else... What is the appropriate way to set these fields?

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