On Mon, Nov 21, 2011 at 6:31 AM, Hasan Rajib Imam <[email protected]>wrote:
> Hello Tom & Nick, > > Thanks for your help. I am here to ask another question. > > I am using the following command > sudo python usrp2_rx_cfile.py -f 800M -N 1000 -d 100 -s -v output.dat > > After that, I converted the .dat file using octave command > (read_complex_binary). > > However, the values I am getting are ambiguous. > I am getting lots of 0 (zeros) and lots of Nan (dont know what does it mean > though)..I have no idea about it. > > Here is the snapshot of what I get. I would really appreciate if somebody can > give any idea about this. Thank you. > > Doesn't the -s option output shorts? When you use the read_complex_binary, it's expecting it as complex floats (32-bit float I, 32-bit float Q). Try capturing without the -s and try again. You might also have to turn up the receiver gain. Tom > > ------snapshot----------- > (9.183409485952689e-41,0) > (NaN,NaN) > (NaN,NaN) > (NaN,NaN) > (NaN,NaN) > (NaN,9.183409485952689e-41) > (NaN,NaN) > (NaN,9.183409485952689e-41) > (NaN,NaN) > (NaN,NaN) > (9.183409485952689e-41,0) > (NaN,9.183409485952689e-41) > (9.183409485952689e-41,0) > (9.183409485952689e-41,9.183409485952689e-41) > (NaN,NaN) > (9.183409485952689e-41,0) > (NaN,NaN) > (0,9.183409485952689e-41) > (NaN,NaN) > (NaN,9.183409485952689e-41) > (NaN,NaN) > (NaN,9.183409485952689e-41) > (0,9.183269356106256e-41) > (9.183409485952689e-41,9.183409485952689e-41) > (9.183409485952689e-41,0) > (9.183409485952689e-41,0) > (9.183409485952689e-41,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > (0,0) > > > > On Sat, Nov 19, 2011 at 12:16 AM, Tom Rondeau <[email protected]>wrote: > >> On Thu, Nov 17, 2011 at 6:41 PM, Hasan Rajib Imam <[email protected]>wrote: >> >>> Hello Nick, >>> >>> Thanks for your reply. >>> >>> >>> "you can use Gnuradio blocks such as the decimating FIR filter to >>> decimate additionally by however much you like." >>> >>> Could you please tell me how can I do the above thing? Actually I am >>> very new to gnuradio. I will really appreciate your help. >>> >>> Thanks. >> >> >> Hasan, >> >> You can use the gr.fir_filter_XXX(decim, taps) or >> gr.fft_filter_XXX(decim, taps). The taps are generally defined using >> gr.firdes.low_pass_2(gain, sample rate, bw, transition, attenuation, >> window). The 'decim' parameter for these blocks is an integer. >> >> fft_filter: >> http://gnuradio.org/doc/doxygen/classgr__fft__filter__ccc.html >> >> fir_filter: >> http://gnuradio.org/doc/doxygen/classgr__fir__filter__ccc.html >> >> firdes: >> http://gnuradio.org/doc/doxygen/classgr__firdes.html >> >> Tom >> >> >> >> >> >>> >>> On Fri, Nov 18, 2011 at 1:29 AM, Nick Foster <[email protected]> wrote: >>> >>>> On Thu, Nov 17, 2011 at 8:28 AM, Nick Foster <[email protected]> wrote: >>>> > On Thu, Nov 17, 2011 at 2:33 AM, hasanimam <[email protected]> >>>> wrote: >>>> >> >>>> >> Hello all, >>>> >> >>>> >> I am here once again and would like to bother you a bit. >>>> >> I am using the usrp2_rx_cfile.py command to get the IQ data from >>>> usrp2. I am >>>> >> using the following command >>>> >> >>>> >> sudo python usrp2_rx_cfile.py -f 800M -d 496 -s -v -N 10 >>>> >> /home/gnuradio4/Desktop/observed_data/test.dat >>>> >> >>>> >> And I am getting the following output: >>>> >> >>>> >> Network interface: eth0 >>>> >> USRP2 address: 00:50:c2:85:35:7d >>>> >> Using RX d'board id 0x0053 >>>> >> Rx gain: 15.75 >>>> >> Rx baseband frequency: 800M >>>> >> Rx DDC frequency: 0 >>>> >> Rx residual frequency: 0 >>>> >> Rx decimation rate: 512 >>>> >> Rx sample rate: 195.312k >>>> >> Receving 10 samples >>>> >> Writing 16-bit complex shorts >>>> >> Output filename: /home/gnuradio4/Desktop/observed_data/test.dat >>>> >> >>>> >> In the above, it shows that the sample rate is 195.312k. I want to >>>> raise >>>> >> this rate but it seems that decimation rate has a limit upto 512 so >>>> i cant >>>> >> do that. >>>> >> Can you suggest me any other way to raise the sample rate? >>>> >> In fact I want the time difference between each sample to be around >>>> 100us, >>>> >> but sample rate 195k gives me 5us. >>>> > >>>> > "Decimation" means the ratio by which the 100MHz main clock is >>>> > divided. 100MHz / 512 = 195.312kHz. Try using a lower decimation. >>>> >>>> Oh, I think I misunderstood your question, sorry -- you don't want to >>>> raise the SAMPLE rate, you want to raise the DECIMATION. In that case, >>>> you can use Gnuradio blocks such as the decimating FIR filter to >>>> decimate additionally by however much you like. >>>> >>>> --n >>>> >>>> > >>>> > --n >>>> > >>>> >> >>>> >> Thank you. >>>> >> >>>> >> >>>> >> -- >>>> >> View this message in context: >>>> http://old.nabble.com/usrp2_rx_cfile.py-issue-tp32860995p32860995.html >>>> >> Sent from the GnuRadio mailing list archive at Nabble.com. >>>> >> >>>> >> >>>> >> _______________________________________________ >>>> >> Discuss-gnuradio mailing list >>>> >> [email protected] >>>> >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>>> >> >>>> > >>>> >>> >>> >>> >>> -- >>> Hasan Rajib Imam >>> University of Electro-Communication, Japan >>> 1st year Masters Student >>> Email: [email protected] >>> Contact No: (+81)80-5004-5931 >>> >>> _______________________________________________ >>> Discuss-gnuradio mailing list >>> [email protected] >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>> >>> >> > > > -- > Hasan Rajib Imam > University of Electro-Communication, Japan > 1st year Masters Student > Email: [email protected] > Contact No: (+81)80-5004-5931 >
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