Hi Jon, Disclaimer: I haven't run your code, but based on eyeballing the png file:
It looks like your "delay" block is not configured properly. The delay should be fft_len + cp_len which is 80 (instead of 72). Best, Aditya On Tue, Mar 18, 2014 at 7:25 PM, Jonathan Fox <[email protected]>wrote: > 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 TX/RX > frequency at 500 MHz. The USRPs used are N210s with WBX daughterboards. I > 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 SMA > cables and a 30 dB attenuator, no over the air transmission. I placed file > 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 > binary files. > > 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 files > have some size to them, implying something has been written. The file sinks > 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 > another 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, all > the binary files after the FFT have no data so something is getting screwed > 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? > > Thank you, > > Jon > > Attached is the python script, grc file, and screen shot of the TXRX combo > in GRC. > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
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