Jeffrey Ung wrote: > Is there any way I could use one USRP to both transmit and receive a > signal? That is, I want to use benchmark_tx.py to send out a dbpsk > modulated signal and use benchmark_rx.py to receive this same signal. > Would this be possible? I'm using a FLEX400 daughterboard. I actually > have two of them.
Yes. It's easiest to use both of them, one in each side. For benchmark_tx.py, use '-T A' to transmit using the FLEX in side A. In another terminal, use benchmark_rx.py with '-R B', to receive with the FLEX on side B. Signal isolation isn't the greatest, though I haven't tested it between different daughterboards in the same USRP case. Whatever you do for an external antenna, do NOT just cross-connect the Tx output and Rx input connectors. There must be at least 20 dB of attenuation, 40 dB is recommended. Otherwise you'll damage the input stage of the receiver. You can do the same with a single FLEX board, but you have to modify the examples to enable using separate Tx and Rx antennas. Leakage is likely to affect your results. In fact, I recall someone saying that leakage on the board was sufficient that they didn't need to hook any antennas or cables between the Tx and Rx ports. -- Johnathan Corgan Corgan Enterprises LLC http://corganenterprises.com _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
