[Discuss-gnuradio] Unexplained out-of-sequence packets...

[Ian Holland]

Hi All

 

I am coming across problems when using USRP2s with certain decimation factors, and these problems are somewhat counterintuitive.

For instance, either using our own code while simply waiting for samples to cross a threshold (so very little computation), I find that I am getting SSS, indicating out-of-sequence packets.

This was for a decimation factor of 20. However, when I tried a decimation factor of 10, which should have increased both the Ethernet and the computational requirements, I no longer observed out-of-sequence packets.

 

I tried the same sort of thing with usrp2_fft.py, trying decimations of 10, 16, and 20. For decimations 16 and 20, I got out-of-sequence packets within about 10 – 20 seconds, but with decimation factor 10 I saw no out-of-sequence packets even after a few minutes.

 

Can anybody suggest what might be going on here?

 

Thanks

 

Ian.