Hi Ali, I have done the similar as a part in my thesis as well. But I used two USRPs to serve as receiver and transmitter. When u try to listen on a daughter board using same USRP and transmit simultaneously ( which I tried ) you do not receive the transmitted signal. I did not dwell much on this because I had two USRPs to serve as two users. I know that both tramsitter and receiver programs can be run using two daughter boards. *But the receiver in this case seems to receive only signals send from other USRPs. But signals Transmitted from a diiferent antenna/daughter board on same USRP was not received*. I used this isolation for my benefit to run a scanner simultaneously to detect signal from while transmission is going on. I do not know if this isolation can be removed by changing some parameters. I do not have access to my boards now will try it next week and let you know.But I would recommend you to search the archive there are some related discussions. Thank you Swapna
2009/3/20 ali siddiqi <[email protected]> > Hi > > I am trying to implement a cognitive radio system for dynamic spectrum > access. I am trying to implement it in GNU radio. But the problem is that i > have only one USRP at the moment with Basic RX and TX daughterboards. The > setup consists of Station A transmitting to Station B. > In order to be able to use the licensed spectrum, the transmitter must know > which channels are free in the vicinity. Thus it has to do a parallel > detection of spectrum as well---receiver mode. > > The Transmitter first senses the spectrum for some time say 10ms and then > transmits on the free frequency for say 90 ms before sensing the spectrum > again and so on. > > Thus the following questions arise: > 1. Can the Station B be implemented on the same USRP when the Station A is > only transmitting[not sensing(recieving)]? > 2. What effects would this have on the Data Rates and any problem with the > USB interface? > > > Is there any built in example within gnuradio with which i can test the > simultaneous transmission and reception from the BasicTX to the BasicRX > respectively on the same usrp? > > Regards, > Ali > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
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