Closed qw-Zhang closed 3 years ago
The 'U's are probably not the problem. I just noticed that the PHY uses packet_len
to mark the start of a frame, while the USRP Sink uses pdu_length
. If you adapt this, the 'U's might disappear. (Let me know if it works, then I'll push a fix.)
But, anyways, your actual issue might be that the USRP might operate in half-duplex mode (i.e., doesn't send and receive at the same time). If you're device is full-duplex-capable, you might have to adapt the parameters (e.g., antennas).
As you mentioned, you can also just use two SDRs, which should work out-of-the-box. I'd change MAC source address and RIME address for the other node, to be able to differentiate them.
Thanks for your reply.
I have revised the parameter "TSB tag name" of USRP Sink block and regenerate OQPSK_PHY with same "packet_len". But I also receive the "UUUU....". I use the two USRP2 as transmitter and receiver. I don't know how to change the MAC source address and RIME address of the two nodes.
gr-ieee 802.15.4 version: maint-3.7
gnuraio version: 3.7.13
This is the flow graph which I used:
And this is the output of gnuradio
This could be a networking issues (from a VM, a switch, etc). Try disabling the USRP source (replace with a vector source that only outputs one sample and then stops). Then check if you still see the 'U's. If this also doesn't work, please try the maint-3.8 branch with GNU Radio 3.8.
Finally, I upgrade gnuradio to version3.8. Everything looks wok well. Thanks for your contribution!
Great. Happy it worked!
Hi Bastian,
The PHY block is generated normally. And the simulation without USRP works well too. But the transceiver_USRP.grc cannot work well, it shows the "UUUU..." in command.
I consider it maybe caused by one PC run transmitter and receiver at the same time. Can I separate the transceiver USRP.grc to one Tx.grc and one Rx.grc and run them at two PC, like gr-ieee 802-11?