Hi Marcus, As i mentioned the flow graph signal blocks i have used in gnu radio companion from that i am getting this out put on FFT sink in GNU radio companion simulation flowgraph which is similar like this
and i have used RF cable to connect from USRP1 TX board to the spectrum analyser RF out put and i am getting the output like this In spectrum analyser iam getting noise and only 1 peak in the middle which does not look like ofdm signal. I insert both the images above so you can have a look and please let me know what could be the problem. I have used 2.4GHz frequency and i am using USRP1 board . i hope the above too diagrams help you to understand my problem. Thanks and Regards, Marcus D. Leech wrote: > > On 10/16/2011 12:29 PM, waqasme wrote: >> Hello all, >> I am trying to transmitt and recieve OFDM signal Via USRP1 board. I made >> basic simulation in GNU radio a signal source block and then interleave >> and >> then OFDM modulator and then channel model block then usrp1 sink and fft >> sink to see the output..In FFT sink at the end it shows proper square >> like >> OFDM signal but on the other hand in spectrum analyser it shows only one >> peak sine wav signal not OFDM. I tried to play with the setiings but >> couldnot get the desired ofdm signal output. This is just tranmitter >> setup >> and i attched with spectrum anlyzer but i dinot get OFDM signal . iam >> only >> getting simple sine wave in the spectrum analyser. I tried with simple >> random sourse block and then DQPSK modulator and Usrp sink then it worked >> it >> shows sine wave signal in out put at spectrum analyser.Please any body >> know >> how to fix this problem or any solution ??? For reciever part i will use >> the >> same block in reverse order with ofdm demodulator.. All suggestions are >> appriciated. >> Looking forward to it... >> >> Thanks in advance.. >> waq. > More specificity is usually required to allow people to help you. > Posting your (GRC-produced) flow-graph would help. > > From your description it's hard for anyone to help you. > > > > -- > Marcus Leech > Principal Investigator > Shirleys Bay Radio Astronomy Consortium > http://www.sbrac.org > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > http://old.nabble.com/file/p32663266/fft%2Bofdm_spectrum.jpg http://old.nabble.com/file/p32663266/fft%2Bofdm_spectrum.jpg http://old.nabble.com/file/p32663266/fft%2Bofdm_spectrum.jpg fft+ofdm_spectrum.jpg http://old.nabble.com/file/p32663266/ofdm_spec.gif -- View this message in context: http://old.nabble.com/OFDM-Transmiter-and-receiver-by-using-USRP1-tp32662445p32663266.html Sent from the GnuRadio mailing list archive at Nabble.com. _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
