Roberto Mastrodonato wrote: > Hi all > > is there anybody that experienced USRP projects with SMART Antenna > technology? If yes, where can I find codes or something else related to > USRP-SMART Antenna? > Thanks a lot I have been experimenting with direction finding and passive radar using gnuradio and multiple antenna's. These experiments are on hold for now, due to lack of time, but I hope to continue with them sometime in the future.
What exactly would you like to do and with how much array-elements. The simplest smart antenna using usrp/gnuradio I can think of is a smart transmitter using two antenna's. The phase-difference you introduce between the two signals, combined with the positioning of your two antenna's determines the maximum and minimum gain direction(s) of the whole system. Introducing a fixed phase difference is just multiplying with a const complex number. Phi=wanted phase difference in radians signal=original signal to transmit sink1=sink where the first output should go sink2=sink where the second output should go phasediff=gr.multiply_const_cc(gr_complex(cos(Phi),sin(Phi)) fg.connect(signal,sink1) fg.connect(signal,phasediff,sink2) The same goes for reception: Phi=expected phase difference in radians input1=signal from first antenna input2=signal from second antenna receiver=reception chain phasediff=gr.multiply_const_cc(gr_complex(cos(Phi),sin(Phi)) adder=gr.add_cc() fg.connect(signal1,(adder,0)) fg.connect(signal2,phasediff,(adder,1)) fg.connect(adder,receiver) If you want to automatically determine the phase-differences and amplitudes things get much more complicated but can still be done. I even tested with a very slow correlator and agc which automatically determined the phase difference of the strongest signal received and tuned the two antenna array for maximum sensitivity for this signal. Greetings, Martin > > Roberto > > > ------------------------------------------------------------------------ > > _______________________________________________ > 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