On 11/09/2010 05:34 PM, Rachel Li wrote: > Hi All: > > I am experiencing something strange with USRP1 and already tried a lot > of approaches to diagnose where the problem is, but no luck so far. > > We have two USRP1, each of which has a RXF 2400 daughter board and an > antenna connected to the Tx/Rx port. When we run benchmark > (benchmark_tx.py and benchmark_rx.py), the packet loss/corrupted rate > is very random (from 0% to 99%). > > We've tried several approaches to diagnose where the problem, including > (1) connect the Tx/Rx ports of two USRP by a SMA connector > (2) try both sides of the mother board (A and B) , > (3) use different central frequency from 2.4G to 2.48G, > (4) adjust the carrier threshold (20 to 50), tx amplitude (0 to 1) and > rx gain (0 to 90), > (5) place the radios in different locations, > (6) use different versions of gnuradio (stable release version 3.3.0 > as well as the latest repository code) > (7) place a fft sink at the rx to observe the spectrum, I can see the > signal spectrum showing up when tx is transmitting something. > > Unfortunately, nothing really helps. > > Is it possible that it is a defective USRP? > > I really appreciate if anyone of you could guide me with this problem > because I have a deadline to make in around 2.5 weeks. > > Thanks very much! > > Rachel > My suggestion is that you use a more basic diagnostic. Do both USRPs have roughly the same sensitivity and output power?
If you transmit on one, and receive on the other with a FFT, with an attenuator between them, can the Rx side "see" the other side, use increasing levels of attenuation until the Rx can't see the transmitted signal anymore. -- Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio