OFDM tranceiver not responding as intended on USRP2

GNU Radio
1

Hi All,

I am implementing a OFDM tranceiver. I am following the benchmark.py and
tunnel.py for achieving it. I am facing the following problems while
performing receive–> transmit–> receive:

1.It receives on the startup of the code.
2.It transmits and then it does not receive at all.

I have tried:

  1. Creating separate thread for send the packet. I am using the queues
    to accumulate the data to be sent and then the queued data is
    transmitted by the send packet thread. This thread will inturn call
    _pkt_input.msgq().insert_tail(msg) in the ofdm_mod class to send the
    data on the msgq. Even this did not solve my problem
  2. Debugging the code by using logs. This clearly shows that, once it
    transmits it does not receive at all. If it does not transmit even once
    then it can receive the data.
  3. I have used file sinks just after the usrp2_source. The size of the
    file indicates that it is receiving the data even after transmission.
    But for some reason it is not being demodulated. Does this transmission
    change the receiving parameters?

Can someone please help me to figure out whats going on?

Thanks and Regards,
Pradeep Nagaraju*