So I have the stock python scripts (tx_ofdm and rx_ofdm) located in the
gr-digital examples and put USRP sources and sinks in the appropriate
spots. I left sampling alone (100K for TX, 3.2M for RX) and had the
frequency at 500 MHz. The USRPs used are N210s with WBX daughterboards.
tested the USRP used for TX out by outputting a signal to another and
looking at it on the GNU Radio spectrum analyzer. Also, this is through
cables and a 30 dB attenuator, no over the air transmission. I placed
sinks after each block in the process; each file is a binary file. After
multiple runs I felt like something wasn’t working after looking at the
When I execute, only the file sinks placed after the Schmidl & Cox OFDM
Synchronizer freq_offset and detect have data in them, at least their
have some size to them, implying something has been written. The file
after FFT (or the header/payload demux) have no data, 0 KB.
When I discovered that the receive didn’t work, I took the grc file
user made back in October with both TX mod and RX demod in the same
flowgraph to see if that would work (files attached). Again same issue,
the binary files after the FFT have no data so something is getting
up in my demod.
Has any user on this list run into this issue before or can offer some
insight to why the receiver is failing?
Attached is the python script, grc file, and screen shot of the TXRX