Hallo people, During my adventure of designing 433MHz receiver i have recently discovered misterious simetrical signal which I am not able to explain to myself. I am using USRP1 with WBX daughter board. While observing complex baseband signal, I realized that depenting on RF gain I have a signal simmetrical to the transmitted signal. I have also attached a photo. Hope that you have some explanation. <http://gnuradio.4.n7.nabble.com/file/n38503/Screen... <http://gnuradio.4.n7.nabble.com/file/n38503/Screen... -- View this message in context: http://gnuradio.4.n7.nabble.com/misterious-symetri... Sent from the GnuRadio mailing list archive at Nabble.com.
on 2012-11-27 17:32
on 2012-11-27 18:36
On Tue, Nov 27, 2012 at 8:31 AM, nexy_sm <vlasinac@gmail.com> wrote: > <http://gnuradio.4.n7.nabble.com/file/n38503/Screen... > <http://gnuradio.4.n7.nabble.com/file/n38503/Screen... > Looks like the effects of IQ imbalance. I didn't read this closely, but this page looks like a pretty good explanation: http://www.dsplog.com/2009/03/08/iq-imbalance-in-t... Tom
on 2012-11-28 15:42
This looks pretty much like my problem. I suppose that it is time for tuning? by the way, can somebody remember the thread with very good GRC demonstrator of IQ imbalance and DC offset? Nemanja -- View this message in context: http://gnuradio.4.n7.nabble.com/misterious-symetri... Sent from the GnuRadio mailing list archive at Nabble.com.
on 2012-12-10 10:19
I have USRP1 equipped with WBX and LFTX and LFRX daughter boards. When want to use /uhd_cal_rx_iq_balance/ to calibrate my WBX board it won't do that, it says that calibration is not supported by hardware. I suppose the problem is uhd wants to calibrate LFRX board, and I don't know how to specify the oder board. Any suggestions? Regards Nemanja -- View this message in context: http://gnuradio.4.n7.nabble.com/misterious-symetri... Sent from the GnuRadio mailing list archive at Nabble.com.
on 2012-12-11 10:33
Guys, any suggestions? I got exactly this error: [savi_ne@ts-070046nl ~]$ uhd_cal_rx_iq_balance --verbose linux; GNU C++ version 4.4.6 20120305 (Red Hat 4.4.6-4); Boost_104100; UHD_003.004.003-221-g9d6f9492 Creating the usrp device with: ... -- Opening a USRP1 device... -- Loading FPGA image: /usr/local/share/uhd/images/usrp1_fpga.rbf... done -- Using FPGA clock rate of 64.000000MHz... Error: This board does not have the CAL antenna option, cannot self-calibrate. Thanks again -- View this message in context: http://gnuradio.4.n7.nabble.com/misterious-symetri... Sent from the GnuRadio mailing list archive at Nabble.com.
on 2012-12-11 15:49
On 12/11/2012 03:32 AM, nexy_sm wrote: > -- Opening a USRP1 device... > -- Loading FPGA image: /usr/local/share/uhd/images/usrp1_fpga.rbf... done > -- Using FPGA clock rate of 64.000000MHz... > Error: This board does not have the CAL antenna option, cannot > self-calibrate. The utilities require transceiver boards like RFX, WBX, SBX. Also unfortunately, requires FPGA support, which is not in USRP1. -josh
on 2012-12-11 17:49
Hm, nothing like USRP1 is not supported is written here: http://files.ettus.com/uhd_docs/manual/html/calibration.html under the section of USRP1 it is even suggested to read. But how to reduce IQ imbalance then? On Tue, Dec 11, 2012 at 3:48 PM, Josh Blum-3 [via GnuRadio] <
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