[Discuss-gnuradio] Strange behavior in digital benchmark examples

[Tuan (Johnny) Ta]

Hello all,

I just came across a strange behavior in the digital benchmark examples that I haven't seen before. The transmitter wouldn't stop itself after it finishes sending the requested data size (specified by -M argument). Keyboard interrupt (ctrl+C) has no effect. I had to stop it with ctrl+Z and kill the job after.

This behavior starts when bitrate exceeds 1M. 

If I ran benchmark_rx2.py then a short period after receiving all packets (~30 sec), the receiver would continuously spill out "O" (overrun). This didn't happen if I ran benchmark_rx.py. (I ran the corresponding tx code.)

I'm not sure what could be causing it. I was able to run digital benchmark code on my older machine at 1.5Mbps prior to UHD (I used Ethernet driver) so I'm sure CPU speed isn't a problem.

To make it work with UHD driver, I made some changes to the usrp_options.py and generic_usrp.py.

I'm quite puzzled right now. I'd appreciate any insights!

Thank you,

Johnny