OFDM modulation in tunnel.py example [USRP2 platform]

GNU Radio
1

Dear GNU Radio list,

I’ve being diving into some GNU Radio examples in order to communicate
two USRP2s (e.g. USRP2 #1 pings USRP2 #2). Following the example
“tunnel.py”, in $GNURADIO_PATH/gnuradio-examples/python/digital, I’ve
been able to do it, but with a GMSK/DBPSK/DQPSK modulation scheme.

My goal is to use the tunnel.py example but using a different modulation
scheme, i.e. OFDM. I’ve seen the example “tunnel.py” in another
directory ($GNURADIO_PATH/gnuradio-examples/python/ofdm), which uses a
OFDM modulation scheme but it seems that it’s only working for USRP1.

Is it possible nowadays to use tunnel.py (transmit and receive
flow-graph in the same USRP2) with OFDM in an USRP2 platform?

Thank you for your help.

My equipement is:
2x USRP2s + XCVR2450 daughterboard
Linux 10.04 (Lucid) - 32 bits
GNU Radio version 3.3.0 (stable version)

Kind Regards,

Juan Ramon Gutierrez A.

2

Hi Juan,

It isn’t too hard to modify the OFDM tunnel script to use UHD instead
of the old USRP blocks.

You have to change the flow graph in tunnel.py to use new sink and
source blocks and update all of the sample rate and frequency setting
functions.

You can take a look at how I did it here:

Hope that helps,
Morgan