[Discuss-gnuradio] Re: Syncrinization of two USRP2s
Johnathan Corgan wrote: On Thu, May 14, 2009 at 7:32 AM, Juha Vierinen jvier...@gmail.com wrote: Calling: -config_mimo(MC_WE_LOCK_TO_SMA) Johnathan It will be grateful if python bindings for config_mimo, sync_every_pps are added to usrp2_base.h and usrp2.i in gr-usrp2. (Until now, I have added them everytime when I updated the gnuradio.) I am using sync_every_pps for synchronizing boundaries of frames transmitted from multiple USRP2. Since the samples are discarded when the samples arrive later than the preset timestamp value, I use sync_every_pps and set timestamp value to in order to guarantee transmission of the frame. Changkyu Seol -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: Re: Single-tone test using USRP2 with RFX2400 and XCVR2450
Johnathan Corgan wrote: Please update your firmware and try again. ?I believe I have fixed this problem now. The USRP2 firmware that contains this fix has been posted to: http://gnuradio.org/releases/usrp2-bin/trunk/txrx_edk10.1_r10925.bin Johnathan Thank you very much for such quick update. The flipping problem is resolved with updated firmware. Changkyu Seol -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: Single-tone test using USRP2 with RFX2400 and XCVR2450
Matt Ettus wrote: Yongsang Kim wrote: What you are seeing are normal transmitter non-idealities, including DC offset (aka carrier feedthrough), and IQ imbalance (aka sideband suppression. These can be improved through tuning, but they are not bad as is. Also, on the XCVR you are seeing the phase noise skirts as well. Matt With the XCVR2450 and USRP2, we also observed that the 2MHz (at baseband) is appearing at (f_c-2MHz) not (f_c+2MHz) where f_c is the center frequency. It seems that the complex conjugate of original baseband signal is transmitted at XCVR2450. We verified this with OFDM signal which is demodulated successfully when we flip the left and right of the FFT ouput before processing (integer frequency offset compensation, channel estimation, etc) at the receiver. -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: USRP2 and external clock (from GPS receiver)
Matt Ettus wrote: The easiest way to check for lock is to put the following line in your firmware: clocks_enable_test_clk(true,10); This will output a test clock on the middle 2 pins of the 4 pin connector right near the VCXO on the motherboard. Look at one of those 2 pins on an oscilloscope at the same time as the 10 MHz reference. You should see the two clocks don't drift relative to each other. I tried as you suggested but it still drifts. I also added the following line in the firmware to make sure. clocks_mimo_config(MC_WE_LOCK_TO_SMA); I tried on several different USRP2s and I got same results. Any more suggestions? -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: Re: USRP2 and external clock (from GPS receiver)
Matt Ettus wrote: Are you sure you have a 10 MHz reference and not some other frequency? Matt Yes. I also have tested with a function generator. Changkyu Seol -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: Re: Re: USRP2 and external clock (from GPS receiver)
Matt Ettus wrote: Changkyu Seol wrote: If you had a real email address, I would send you some code to try. Matt I sent you an email in order to let you know my email address. Changkyu Seol -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: Re: Re: USRP2 and external clock (from GPS receiver)
Matt Ettus wrote: Changkyu Seol wrote: If you had a real email address, I would send you some code to try. Matt Thank you for the files. I tested as you suggested with firmware and fpga files you sent me and it is locked!! I used it other USRP2s and all worked fine. I modified and compiled txrx.c in gnuradio (revision 10464, fedora 9) trunk to generate txrx.bin. What was the problem? Changkyu Seol -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: Re: Re: USRP2 and external clock (from GPS receiver)
Changkyu Seol wrote: Matt Ettus wrote: Thank you for the files. I tested as you suggested with firmware and fpga files you sent me and it is locked!! I used it other USRP2s and all worked fine. I modified and compiled txrx.c in gnuradio (revision 10464, fedora 9) trunk to generate txrx.bin. What was the problem? Changkyu Seol I downloaded GNU radio by following command. (I am not used to linux.) $ svn co http://gnuradio.org/svn/gnuradio/trunk gnuradio txrx.c included seems to be very old version. Where can I get the latest firmware/fpga source codes? -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] USRP2 and external clock (from GPS receiver)
Hi! I am planning to implement multiple synchronized transmitters using USRP2 and GPS receiver. Before that I checked whether the USRP2 is locked to external clock through following experiment. 1) Connect the 10MHz and 1PPS from GPS receiver (EP1S, Spectracom) to USRP2's REF and PPS in port, respectively. (I definitely checked the electrical specifications...) 2) Generate 10MHz tone from the USRP2 using usrp2_siggen.py. I have included following lines in python code. self._u.config_mimo((0x0001 | 0)) --- I added this method in usrp2.i, etc... self._u.sync_to_pps() 3) Compare the 10MHz tones coming from GPS and the USRP2 through oscilloscope (triggered to 10MHz sine wave from GPS). I expect that timing drift of the 10 MHz sine wave from USRP2 will be nearly 0 or at least very slow, but it is still very fast. It seems that including self._u.config_mimo((0x0001 | 0)) doesn't change anything. (I did update the fpga programming file and the firmware in SDcard.) Am I missing something? Any comments will be appreciated. Changkyu Seol -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Re: Installing GNU radio
Karthik Vijayraghavan wrote: You need the GNU scientific library gsl package since it is a pre-requisite for installing gnuradio, http://www.gnu.org/software/gsl/ Karthik I mentioned that I have already installed GSL. -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Installing GNU radio
Hi I am trying to install latest GNU radio in the development trunk which requires GSL (which I have installed already). However, I got following messages and cannot install gnuradio-core and the most of the components. $ ./configure --with-boost=/opt/boost_1_36_0 . . . checking for GSL... no gnuradio-core requires package gsl, not found. Not building component gnuradio-core. . . . I am using fedora 6. Any guidance or comments will be appreciated. Changkyu Seol -- Posted via http://www.ruby-forum.com/. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
