On 10/22/07, [EMAIL PROTECTED] < [EMAIL PROTECTED]> wrote: > > Send Discuss-gnuradio mailing list submissions to > [email protected] > > ------------------------------ > > Message: 6 > Date: Mon, 22 Oct 2007 10:43:50 +0100 > From: Tom Rondeau <[EMAIL PROTECTED]> > Subject: Re: [Discuss-gnuradio] benchmark_ofdm_rx not working > To: GNU Radio Discuss <[email protected]> > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Archana Ragothaman wrote: > > Hello, > > > > I am using two USRPs rev 4 and two RFX2400. I am basically trying to > > make the USRPs communicate with each other using the > > benchmark_ofdm_tx.py and benchmark_ofdm_rx.py scripts. The commands I > > am executing are > > > > ./benchmark_ofdm_tx.py -f2.4e9 -T A (at one USRP connected to laptop) > > > > ./benchmark_ofdm_rx.py -f2.4e9 -R A (at the other USRP connected to > > another laptop) > > > > The benchmark_ofdm_tx.py script is working as I can see the packet > > number displayed(I wrote a print pktno in the script) > > > > However the benchmark_ofdm_rx.py script does not give any output. I > > don't think the rx_callback function is being executed(as the packets > > are printed in that function). > > > > Can anyone please help me out and give suggestions as to what the > > problem could be? > > > > Thank you. > > First, try running the benchmark_ofdm_tx on one side and tht usrp_fft to > display the received power at the receiver. What does this look like? > > The problem is likely that you are not transmitting enough power. There > is a --tx-amplitude flag to adjust this. Set it to 2000 - 4000. > > Tom
Hello, I increased the amplitude to around 3000 on the tx usrp. I also ran the usrp_fft.py on the rx side. I could observe the spectrum of the rx signal which was around 30 dB. So I know that the rx side usrp is able to receive the packets trasnmitted. However, now when I run the benchmark_ofdm_rx.py script on the rx side, I do not see any output. The output that I get is After rx_callback( ) definition >>> gr_fir_ccf: using SSE >>> gr_fir_fff: using SSE INIT Completed Successfully!!!! fg=usrp_graph(....) called (comment added for debugging) gr_buffer::allocate_buffer: warning: tried to allocate 20 items of size 1600. Due to alignment requirements 64 were allocated. If this isn't OK, consider padding your structure to a power-of-two bytes. On this platform, our allocation granularity is 4096 bytes. fg.start() (comment added for debugging) Inside RX _Callback pktno (comment added for debugging) ok: False pktno: 58626 n_rcvd: 1 n_right: 0 Only one packet is received after a long time. Could you suggest as to why the output is not displayed? - - Archana Ragothaman Master's in Telecommunications Graduate Research Assistant MIND Lab,UMIACS University of Maryland, College Park Email: [EMAIL PROTECTED] Phone: 240-422-7887
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