Hello Thomas H Kim: I assume you have the two clocks synchronized. There is a 10 MHz reference clock input on the front of the USRP2. But on the USRP you need to get a soldering iron and modify the hardware a little (I think you need to remove a resistor, or something like that) to add a 10 MHz reference input.
You could also the use the 1 PPS input for your two USRPs. Let me know if this helps. Steve --- On Mon, 1/10/11, Thomas H Kim <thomas.h....@aero.org> wrote: From: Thomas H Kim <thomas.h....@aero.org> Subject: [Discuss-gnuradio] Benchmark scripts To: discuss-gnuradio@gnu.org Date: Monday, January 10, 2011, 3:55 PM All, I am testing 2x USRP1 with RFX2400 daughter cards with benchmark_rx and benchmark_tx scripts and have questions. When I set the MCS to dbpsk, error rate I got was close to zero. When I set it to dqpsk, d8psk, error rate is 100%. When I set it to gmsk, certain daughter cards had close to 0 error rate, but certain swung from 0% to 100%. I asked about it to Ettus research, they told me that it's likely to be due to frequency offset between the two boxes I have. If it is true, 1) how can I compensate the offset? 2) Has someone used dqpsk, d8psk in 2.4MHz ISM band before? If so, what extra step is necessary? Thanks, Thomas -----Inline Attachment Follows----- _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
