Hello Yes, I think this is the same thing I am trying to do, but I am not getting the results I expected. Can you please share the GRC file for this. In my execution, I was getting null signals. You can see my setup in the attached file. It's a rather simple version just for illustration. I don't understand why that is not working.
On Sun, Jan 3, 2016 at 7:45 PM, Ron Economos <w...@comcast.net> wrote: > If you want to see individual carriers, you have to use a high resolution > FFT. Here's a 262144 point FFT on a DVB-T2 OFDM signal with a 1K FFT (853 > active carriers). The carriers are spaced about 9 kHz. Stronger tones are > pilots. > > https://twitter.com/drmpeg/status/670769195160858624 > > Ron > > > On 01/03/2016 04:34 PM, Aditya Virmani wrote: > > Hello sir > > Thank you for your reply. Well, I am trying to do some additional > operation to the receiver side of the OFDM transceiver (rx_OFDM). > I am intending to detect a doppler shift in the received signal, for which > I am trying to do an FFT over symbols collected in 1 second. > To test the case, I tried to do a large FFT over 4 same OFDM symbols, > which means a 4 x 64 FFT, which should give me 48 (corresponding to > occupied tones) peaks instead of a band. > > The theory of peaks can be illustrated simply by the FFT theory. I can > share the reference for that if needed. > > I hope I am clear here. > > On Sun, Jan 3, 2016 at 7:06 PM, Martin Braun <martin.br...@ettus.com> > wrote: > >> Typically, you'd do 1 (I)FFT per OFDM symbol. I recommend having a look >> at the tx_ofdm.grc and rx_ofdm.grc examples, which show a full flow graph. >> >> M >> >> On 01/03/2016 01:22 PM, Aditya Virmani wrote: >> > Hello everyone >> > >> > Iam trying to do run-time FFT over multiple OFDM symbols. >> > For this, I feed in the same sequence of bytes for each OFDM symbol. >> > As per my understanding, as I am feeding in the same sequence of bytes, >> > it should be generating same set of symbols, and then further if we do >> > FFT over multiple symbols which are same, we should get a sequence of >> > peak-and-zeros, instead of continuous FFT graph. >> > This works fine if I do just with two symbols (screenshot of that >> > attached), but when I feed in more than two, it results in error ( I >> > think that the data doesn't reach the FFT block concurrently, because >> > the graph I get is same when I feed Null source and a Symbol source to >> > FFT). >> > >> > It would be great if someone can guide me with it. >> > >> > >> > Regards >> > Aditya Virmani >> > >> > >> > _______________________________________________ >> > Discuss-gnuradio mailing list >> > Discuss-gnuradio@gnu.org >> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > > > _______________________________________________ > Discuss-gnuradio mailing > listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
sampled.grc
Description: Binary data
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