I just updated the examples in gr-digital/examples/ofdm using the
feedback I got the last couple of weeks. They’re in the current master,
so if you want to check them out you probably need to git pull first.
Some notes on the examples:
- ofdm_loopback.grc is probably where you want to start playing around.
This gives you a configurable hier block for both transmitter and
receiver. It uses a channel model block to simulate the channel, and
you can play around with the SNR, frequency offset, channel
coefficients to figure out how far you can take the transceiver chain
before it can’t cope.
- rx_ofdm.grc and tx_ofdm.grc demonstrate the inner workings of the hier
blocks. I’ve made them loopback examples too, now, so they immediately
run stand-alone and you can see what’s happening at all places in the
flow graph without having to feed them file data etc.
You can use these to connect tag debugs, scope sinks, FFT sinks,
constellation sinks etc. at any place in the flow graph and thus find
out how the OFDM blocks actually work.
If you want to implement new equalizers, working off of rx_ofdm.grc is
probably a good idea, because you can change the value of
payload_equalizer to whatever you like.
NOTE: If you want to change the modulation type of the payload (e.g.
from QPSK to 8-PSK) you have to change it both in the transmitter
and receiver, in any of these examples.
Karlsruhe Institute of Technology (KIT)
Communications Engineering Lab (CEL)
Dipl.-Ing. Martin B.
Phone: +49 721 608-43790
Fax: +49 721 608-46071
KIT – University of the State of Baden-Württemberg and
National Laboratory of the Helmholtz Association