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. ------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 <trondeau1...@gmail.com>wrote: > On Thu, Nov 17, 2011 at 6:41 PM, Hasan Rajib Imam <shuvo1...@gmail.com>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 <n...@ettus.com> wrote: >> >>> On Thu, Nov 17, 2011 at 8:28 AM, Nick Foster <n...@ettus.com> wrote: >>> > On Thu, Nov 17, 2011 at 2:33 AM, hasanimam <shuvo1...@gmail.com> >>> 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 >>> >> Discuss-gnuradio@gnu.org >>> >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>> >> >>> > >>> >> >> >> >> -- >> Hasan Rajib Imam >> University of Electro-Communication, Japan >> 1st year Masters Student >> Email: shuvo1...@gmail.com >> Contact No: (+81)80-5004-5931 >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> > -- Hasan Rajib Imam University of Electro-Communication, Japan 1st year Masters Student Email: shuvo1...@gmail.com Contact No: (+81)80-5004-5931
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