I am working with Flex2400 boards and the USRP. I have a question
about the digital module (GMSK data transfer). I observe this: When
I send 660 packets , I receive less than 400 of them and less than
200 are correct.
I setup two PCs with ubuntu and with an USRP each. The antennas were
connected to the TX/RX ports on each USRP and separated around 3.2m.
tests such as oscope and fft work fine, with one side sending. Then with
benchmark, on one end I use:
./benchmark_tx.py -f 2.412G --tx-amplitude=20000 -v -r 500k
and the other
./benchmark_rx.py -f 2.412G --rx-gain=70 -v -r 500k
For different runs, errors happen and in a typical run I get something
ok = False pktno = 662 n_rcvd = 355 n_right = 164
I did the following (which did not help)
- varied rx gain and tx_amplitude over a range
- checked the frequency 2.412 (using oscope and iwlist) and also
other free frequencies
- repeated experiment at a different time and day
The ratio of the pktno to n_rcvd and n_right remains almost the same for
Further, if I send send traffic the other way, I get lesser number of
packets (100) correct.
Has anyone seen something like this? Specifically, I am looking at why
RX would receive only a fraction of packets and why only a smaller
would pass crc?
Thanks for your help,
P.S. I am attaching the output of the rx side.