Re: [Discuss-gnuradio] Issue with deinterleave block from a file source to USRP sink with x300

On 22.09.2014 23:50, Ruben.Merz@swisscom.com wrote:
> We are using a similar setup to transmit a 2x2 MIMO OFDM waveform on the
> x300. Because we were not sure what to assume from a TX synchronization
> point of view, we decided to put the IQ samples of both channels
> interleaved in one file. We figured that reading them in sequence, IQ
> sample by IQ sample, would definitely ensure that both channels are
> synchronized.
>
> But, now that I understand better how to synchronize both channels via
> the UHD API, I could probably use two files, one for each channel. Any
> comment?

Yes, that would be the way to do it. Effectively, from the UHD sink's
point of view, this is what you're already doing.

M

>
> Thanks
>
> Ruben
>
> *From:*Martin Braun [mailto:martin.braun@ettus.com]
> *Sent:* Monday, September 22, 2014 8:54 PM
> *To:* Merz Ruben, INI-INO-ECO-MXT
> *Subject:* Re: [Discuss-gnuradio] Issue with deinterleave block from a
> file source to USRP sink with x300
>
> Ruben,
>
> I can replicate this, and am also puzzled. Will be checking if this is
> an UHD issue, or a GNU Radio thing (which seems more likely given that
> this only happens with the deinterleaver).
>
> Why do you have your data in an interleaved file? This seems unnecessary.
>
> M
>
> On Fri, Sep 19, 2014 at 2:58 PM, <Ruben.Merz@swisscom.com
> <mailto:Ruben.Merz@swisscom.com>> wrote:
>
> Hello,
>
> I have the following setup: a file source, a deinterleave block and
> a USRP sink (see the attached .grc and related .png). This setup is
> a test to distribute two different signals on two channels of the
> USRP x300 (the file source loads a binary file with alternated
> channels containing 64 bit long IQ samples - 32 real followed by 32
> imaginary - channel 1/channel 2/channel 1/channel 2/etc...).
>
> The hardware is a USRP x300 with two wideband SBX (SBX-120) boards.
>
> Now, the above setup used to function without a hitch. But recently,
> it completely freezes gnuradio. Basically, I start the flowgraph and
> quickly get a large number of 'L' and no signal is transmitted. The
> only thing I can do is then to kill gnuradio-companion and related
> python processes.
>
> The interesting thing is that if I replace the deinterleave block by
> a "stream to streams" block, everything works fine. I am bit puzzled
> as to what I am missing.
>
> The operating system is Ubuntu 14.04 LTS (updated state), UHD is the
> head of the maint branch, and gnuradio as well
> (UHD_003.007.002-2-gdb35bf46 and Gnuradio:
> 9dcb5067c55a0630c9edca6b62a32b1f8e633930). Firmware is also the most
> recent. I have attached the .grc, and the binary file I am using can
> be obtained here:
> http://www.net.t-labs.tu-berlin.de/~ruben/files/sine_test_10kHz_20kHz_cpx_float_2chan_interleaved_1MSs.bin.
>
> Assuming there is not something wrong in my .grc setup, how do I
> debug this issue?
> Thanks for any suggestion or help,
> Ruben
>
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