On Sat, 2 Jun 2012 17:47:50 -0400, Nick Iliev wrote: > Hello, > > we have implemented a 2 TX x 1 RX MISO testbed with GNU Radio 3.4 and > USRP1 . Both transmitters are using at 2.4GHz ( actually tx1 uses > 2.401GHz and tx2 uses 2.403GHz ) , and are sending data ( BPSK > modulated ) at the same time ( in the same time slot ). >
What is the frequency setting at the receiver side? Do you use two daughter boards at the receiver? If there's only one daughter board I think the receiver can only lock to one frequency and the transmitter of the different frequency might just create interferce. Also you should consider to compensate the possible frequency offset between tx and rx in real world. [1] I think you can use two daughter boards at the receiver and make them to receive signals from two frequencies, but that's not typical MIMO setup. IMHO setting up MIMO with USRP1 is not very easy. You need to make hardware modification to make two USRPs synchronize with one master device or an external clock. You can find some more info from [2]. [1] http://gnuradio.org/redmine/projects/gnuradio/wiki/FAQ#Why-is-there-always-a-frequency-offset-when-transmitting-from-one-USRP-to-another [2] http://gnuradio.org/redmine/projects/gnuradio/wiki/USRPClockingNotes Alick _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
