[Discuss-gnuradio] Need for explanation of blocks in gnuradio
Hi everyone, Can anybody explain me what are the functions of frequency xlating block and wbfm receive pll block.I searched lot of web pages but couldn't find any proper documentation on it. Thanks in advance Sandhya ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Question over the Silder in GRC
On Wed, Oct 09, 2013 at 05:15:04PM -0400, Baokun Liu wrote: Hi all, I am using USRP N210 and GRC. I have a question over changing a USRP parameter using a slider in GRC. If I want to change the TX frequency from 2GHz to 4GHz using a slider, as we know, during this process, the slider would experience many in-between values, such as 2.1, 3, 3.55, 3.888 and so on, how USRP would react to these in-between values? Is there some mechanism to prevent the USRP from overloaded if I move the slider very fast? Should the slider value hold on for some time before sending the value to USRP? Hi Baokun, haven't checked this, but are you sure the event doesn't get triggered once you let go of the slider? At least that's what I thought would happen. MB -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-43790 Fax: +49 721 608-46071 www.cel.kit.edu KIT -- University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association pgpNuMBF5hTHS.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] More wishes for GRC
On Wed, Oct 09, 2013 at 08:12:35PM -0400, Marcus D. Leech wrote: [Ideas] Marcus, can you please add them to http://gnuradio.org/redmine/projects/gnuradio/wiki/GRCroadmap? Thanks, MB -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-43790 Fax: +49 721 608-46071 www.cel.kit.edu KIT -- University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association pgpRmn9OgpW0x.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Radio interoperability
Hi Bijendra, it's not quite clear what your question is. A couple of things you might want to consider: - AM is per se noisy. A commercial HF receiver would also have much better filters than you can achieve with an LFRX-only setup, so expect much noise here - FM is much better with noise. - You're not supposed to rx AM signals with an FM receiver. - VHF and HF usually designate (separate) frequency ranges. So when talking about 'interoperability' between those, most people will be confused. Well, I am. MB On Thu, Oct 10, 2013 at 12:58:06PM +0530, Bijendra Singh wrote: Hello every one, I'm working on a college level project to show interoperability between HF and VHF radio using GNU radio. My aims are listed below: 1) To obtain FM transmitter and receiver waveform in GNU radio as flowgraph, so that i can communicate between laptop and VHF radio (In my case I'm using radio of the range 30-89.899 MHz) :- This I have already achieved 2) To obtain AM transmitter and receiver waveform in GNu radio as flowgraph, so that I can communicate between laptop and HF radio (In my case I'm using a HF radio of the range 3-30 MHz) :- I was able to download a SSB receiver and it is functional but the noise level is high. 3) To integrate Fm transmitter with AM receiver, so that one way communicaton is possible from HF radio to VHF radio. :- This I have already achieved, but with too much of noise and low pitch voice. 4) To integrate AM transmitter with FM receiver so that one way communication is possible from VHF radio to HF radio. I'm still lackung behind in this. 5) To integrate both the 3rd and 4rth flowgraphs in a single flowgraph to make Hf and VHF radio interoperable from both sides. 6) My GNU version is 3.6.4.1, I'm using two usrp's 1 for the HF with lftx and lfrx daughter boards and the other for VHF with basic trans and basic receive daughter cards.Also I'm using dipole antenna. 0 Please guide me. I'm here attaching some .grc file I have downloaded, and which are working in my GNU, but noisy( only ssb_rx is noisy and sstx1 is not working) ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-43790 Fax: +49 721 608-46071 www.cel.kit.edu KIT -- University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association pgpB1nazkun0w.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Radio interoperability
Well it is a project I'm working on. I am trying to receive an AM signal from HF radio which will be provided in the usrp source in my gnu and will transmit a FM signal as output in the usrp sink which I'm trying to send it to the VHF radio. And vice versa. I'm using CNR-900 VHF radio which freq range is 30 to 89.899 MHz and RS-HX radio which freq range is 3 to 30 MHz. When I tried the hf2vhf.grc file, it is working, but with noise. Same thing will be possible for VHF to Hf, I guess. And I'm stuck in this. Any possible remedies?? On Thu, Oct 10, 2013 at 1:48 PM, Martin Braun (CEL) martin.br...@kit.eduwrote: Hi Bijendra, it's not quite clear what your question is. A couple of things you might want to consider: - AM is per se noisy. A commercial HF receiver would also have much better filters than you can achieve with an LFRX-only setup, so expect much noise here - FM is much better with noise. - You're not supposed to rx AM signals with an FM receiver. - VHF and HF usually designate (separate) frequency ranges. So when talking about 'interoperability' between those, most people will be confused. Well, I am. MB On Thu, Oct 10, 2013 at 12:58:06PM +0530, Bijendra Singh wrote: Hello every one, I'm working on a college level project to show interoperability between HF and VHF radio using GNU radio. My aims are listed below: 1) To obtain FM transmitter and receiver waveform in GNU radio as flowgraph, so that i can communicate between laptop and VHF radio (In my case I'm using radio of the range 30-89.899 MHz) :- This I have already achieved 2)To obtain AM transmitter and receiver waveform in GNu radio as flowgraph, so that I can communicate between laptop and HF radio (In my case I'm using a HF radio of the range 3-30 MHz):- I was able to download a SSB receiver and it is functional but the noise level is high. 3) To integrate Fm transmitter with AM receiver, so that one way communicaton is possible from HF radio to VHF radio. :- This I have already achieved, but with too much of noise and low pitch voice. 4) To integrate AM transmitter with FM receiver so that one way communication is possible from VHF radio to HF radio. I'm still lackung behind in this. 5) To integrate both the 3rd and 4rth flowgraphs in a single flowgraph to make Hf and VHF radio interoperable from both sides. 6) My GNU version is 3.6.4.1, I'm using two usrp's 1 for the HF with lftx and lfrx daughter boards and the other for VHF with basic trans and basic receive daughter cards.Also I'm using dipole antenna. 0 Please guide me. I'm here attaching some .grc file I have downloaded, and which are working in my GNU, but noisy( only ssb_rx is noisy and sstx1 is not working) ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-43790 Fax: +49 721 608-46071 www.cel.kit.edu KIT -- University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association ___ 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] FIL1 on WBX gdb
Hi, i cannot find the value of the FIL1 component on the gdb from the WBX (v2). Could you give me the partnumber or specifications? Gr. Simon ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] FIL1 on WBX gdb
Sorry, wrong list. On 10-10-13 10:42, Simon IJskes wrote: Hi, i cannot find the value of the FIL1 component on the gdb from the WBX (v2). Could you give me the partnumber or specifications? Gr. Simon ___ 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
Re: [Discuss-gnuradio] Need for explanation of blocks in gnuradio
Hi Sandhya, the official documentation for the frequency xlating fir filter (http://gnuradio.org/doc/doxygen/classgr_1_1filter_1_1freq__xlating__fir__filter__ccc.html) says: FIR filter combined with frequency translation with gr_complex input, gr_complex output and gr_complex taps. This class efficiently combines a frequency translation (typically down conversion) with a FIR filter (typically low-pass) and decimation. It is ideally suited for a channel selection filter and can be efficiently used to select and decimate a narrow band signal out of wide bandwidth input. Uses a single input array to produce a single output array. Additional inputs and/or outputs are ignored. And that's exactly what it does: It takes coefficients of a FIR filter, and applies them to the signal, simultaneously shifting its frequency. As far as I remember, it does that by dynamically updating the taps by multiplying them with a complex sinusoid of the negative desired shift frequency. These taps are then applied to the signal, before that get's shifted by the shift frequency. There is a discussion going on on the sign of the exponent, so look for Achilleas recent posts with the title Bug in freq_xlating_fir_filter_XXX. However, best explanation is probably the source code, if you're not content with the documentation. Enhancing documentation is always welcome! See gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t and gr-filter/lib/freq_xlating_fir_filter_XXX_impl.h.t; nothing overly complex. Regarding to WBFM receive: You're right, documentation is sparse here. Strangely, the class itself (analog.wfm_rcv_pll) does not even show up in the current sphinx documentation. So there's only the sources left to consult: gr-analog/python/analog/wfm_rcv_pll.py. Luckily, there's a lot of comments in the code, so maybe that will help you understand what's going on internally (so what really making that thing decode stereo radio ;) ). Hope I was a bit helpful today, Marcus ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Need for explanation of blocks in gnuradio
Hi Marcus Thanks for the explanation.It really helped me Thanks and regards Sandhya On Thu, Oct 10, 2013 at 3:21 PM, Marcus Müller mar...@hostalia.de wrote: Hi Sandhya, the official documentation for the frequency xlating fir filter ( http://gnuradio.org/doc/**doxygen/classgr_1_1filter_1_** 1freq__xlating__fir__filter__**ccc.htmlhttp://gnuradio.org/doc/doxygen/classgr_1_1filter_1_1freq__xlating__fir__filter__ccc.html) says: FIR filter combined with frequency translation with gr_complex input, gr_complex output and gr_complex taps. This class efficiently combines a frequency translation (typically down conversion) with a FIR filter (typically low-pass) and decimation. It is ideally suited for a channel selection filter and can be efficiently used to select and decimate a narrow band signal out of wide bandwidth input. Uses a single input array to produce a single output array. Additional inputs and/or outputs are ignored. And that's exactly what it does: It takes coefficients of a FIR filter, and applies them to the signal, simultaneously shifting its frequency. As far as I remember, it does that by dynamically updating the taps by multiplying them with a complex sinusoid of the negative desired shift frequency. These taps are then applied to the signal, before that get's shifted by the shift frequency. There is a discussion going on on the sign of the exponent, so look for Achilleas recent posts with the title Bug in freq_xlating_fir_filter_XXX. However, best explanation is probably the source code, if you're not content with the documentation. Enhancing documentation is always welcome! See gr-filter/lib/freq_xlating_**fir_filter_XXX_impl.cc.t and gr-filter/lib/freq_xlating_**fir_filter_XXX_impl.h.t; nothing overly complex. Regarding to WBFM receive: You're right, documentation is sparse here. Strangely, the class itself (analog.wfm_rcv_pll) does not even show up in the current sphinx documentation. So there's only the sources left to consult: gr-analog/python/analog/wfm_**rcv_pll.py. Luckily, there's a lot of comments in the code, so maybe that will help you understand what's going on internally (so what really making that thing decode stereo radio ;) ). Hope I was a bit helpful today, Marcus __**_ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/**listinfo/discuss-gnuradiohttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Radio interoperability
Hi Bijendra, I, too, am confused. So let's try to understand what you are doing here! On 10/10/2013 10:39 AM, Bijendra Singh wrote: Well it is a project I'm working on. I am trying to receive an AM signal from HF radio Yes, so receiving amplitude modulated audio on a carrier somewhere between 3MHz and 30Mhz (==HF) which will be provided in the usrp source in my gnu You want to capture that using a USRP and GNU Radio, I presume. and will transmit a FM signal as output Aaaaha! Second chain of operation! You want to simultaneously generate an FM signal in the usrp sink which I'm trying to send it to the VHF radio. And you want to transmit that using a USRP (the same USRP?) to another Radio receiver, that listens on a VHF carrier (30MHz-300MHz) then. And vice versa. Huh? Your radio receivers usually can't transmit, so that's confusing I'm using CNR-900 VHF radio which freq range is 30 to 89.899 MHz and RS-HX radio which freq range is 3 to 30 MHz. When I tried the hf2vhf.grc file, it is working, but with noise. Same thing will be possible for VHF to Hf, I guess. And I'm stuck in this. Any possible remedies?? OOh ok... this is military communications, and I was under the impression we're talking broadcast Radio stations. I must try to reunderstand now: You're trying to set up a relay station, for someone with some kind of HF AM tactical radio to communicate with someone with a VHF FM tactical radio, right? Anyway, Martin is right: Whatever you do, AM will always be noisy because it's AM, and unless you use laaarge antennas the HF signal on the USRP will most probably be strongly attenuated (1/2 wavelength of 30MHz is 5m...). So your SNR gets even worse. Greetings, Marcus On Thu, Oct 10, 2013 at 1:48 PM, Martin Braun (CEL) martin.br...@kit.edu mailto:martin.br...@kit.edu wrote: Hi Bijendra, it's not quite clear what your question is. A couple of things you might want to consider: - AM is per se noisy. A commercial HF receiver would also have much better filters than you can achieve with an LFRX-only setup, so expect much noise here - FM is much better with noise. - You're not supposed to rx AM signals with an FM receiver. - VHF and HF usually designate (separate) frequency ranges. So when talking about 'interoperability' between those, most people will be confused. Well, I am. MB On Thu, Oct 10, 2013 at 12:58:06PM +0530, Bijendra Singh wrote: Hello every one, I'm working on a college level project to show interoperability between HF and VHF radio using GNU radio. My aims are listed below: 1) To obtain FM transmitter and receiver waveform in GNU radio as flowgraph, so that i can communicate between laptop and VHF radio (In my case I'm using radio of the range 30-89.899 MHz) :- This I have already achieved 2)To obtain AM transmitter and receiver waveform in GNu radio as flowgraph, so that I can communicate between laptop and HF radio (In my case I'm using a HF radio of the range 3-30 MHz):- I was able to download a SSB receiver and it is functional but the noise level is high. 3) To integrate Fm transmitter with AM receiver, so that one way communicaton is possible from HF radio to VHF radio. :- This I have already achieved, but with too much of noise and low pitch voice. 4) To integrate AM transmitter with FM receiver so that one way communication is possible from VHF radio to HF radio. I'm still lackung behind in this. 5) To integrate both the 3rd and 4rth flowgraphs in a single flowgraph to make Hf and VHF radio interoperable from both sides. 6) My GNU version is 3.6.4.1, I'm using two usrp's 1 for the HF with lftx and lfrx daughter boards and the other for VHF with basic trans and basic receive daughter cards.Also I'm using dipole antenna. 0 Please guide me. I'm here attaching some .grc file I have downloaded, and which are working in my GNU, but noisy( only ssb_rx is noisy and sstx1 is not working) ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org mailto:Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-43790 Fax: +49 721 608-46071 www.cel.kit.edu http://www.cel.kit.edu KIT -- University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org mailto:Discuss-gnuradio@gnu.org
Re: [Discuss-gnuradio] Error in installation of gqrx
On Thu, Oct 10, 2013 at 7:00 AM, Manu T S manu.t.s...@gmail.com wrote: Hi Alex, I am using PyBOMBS for installation. PyBOMBS installed GNU Radio(3.7) to a local directory instead of /usr/local. In my case this directory is /home/manu/gr/target/. The files missing are there in /home/manu/gr/target/include/gnuradio, while they are not found in my old installation (3.6.* inside /usr/local). I want gqrx also to work with the new (3.7), and I used PyBOMBS to install. So it could be that the qmake is not able to locate the header files in ~/gr/target/include/gnuradio. Is there a way to specify that in the recipes? The gqrx build system based on qmake uses pkg-config to find the gnuradio dependencies. The environment to find the pkg-config scripts is set up by pybombs; however, if you have gnuradio 3.6 installed system wide in /usr/local/ the old pkg-config files may interfere with pybombs. I see no other safe option than to remove gnuradio 3.6 from /usr/local. If you still need gnuradio 3.6 you can install it under a prefix other than /usr/local. As long as you have gnuradio 3.6 in /usr/local it will interfere, not only with gqrx but other applications as well. Alex ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] controlling flowgraph
Hi all guys, I wanted to implement a ask transmitter and a button for triggering transmition of a single frame of data. My idea was to do that with a sort of state machine and a button, but as far as i can see there is no button in wx gui blocks. How do uo usually do this? Many thanks, -- Nemanja Savić ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Summary of embedded working group at GRCON13
I've taken the notes we made on the board and put them on the wiki at: http://gnuradio.org/redmine/projects/gnuradio/wiki/GRCon13Embedded Please add you name to the attendee list and edit as needed. The next question is how do we keep the conversation going and how do we actually get the work done. Philip ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Summary of embedded working group at GRCON13
It is great to see some of the working group notes coming up for all to work with on the GR wiki. I'm thinking it would be great to see other working group notes doing the same. I know there's a page for GRC improvements, which maybe is related to the discussion group as well as the email and #irc discussions. I'd love to see the same for the other working groups. Do we think it's worth the time for each working group leader to create a page on the wiki and point the community to it? I do ... - MLD On Oct 10, 2013, at 7:19 AM, Philip Balister phi...@balister.org wrote: I've taken the notes we made on the board and put them on the wiki at: http://gnuradio.org/redmine/projects/gnuradio/wiki/GRCon13Embedded Please add you name to the attendee list and edit as needed. The next question is how do we keep the conversation going and how do we actually get the work done. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Summary of embedded working group at GRCON13
Great idea! In fact, it's so good, it's already been implemented: http://gnuradio.org/redmine/projects/gnuradio/wiki/GRCon13WG MB On Thu, Oct 10, 2013 at 08:02:22AM -0400, Michael Dickens wrote: It is great to see some of the working group notes coming up for all to work with on the GR wiki. I'm thinking it would be great to see other working group notes doing the same. I know there's a page for GRC improvements, which maybe is related to the discussion group as well as the email and #irc discussions. I'd love to see the same for the other working groups. Do we think it's worth the time for each working group leader to create a page on the wiki and point the community to it? I do ... - MLD On Oct 10, 2013, at 7:19 AM, Philip Balister phi...@balister.org wrote: I've taken the notes we made on the board and put them on the wiki at: http://gnuradio.org/redmine/projects/gnuradio/wiki/GRCon13Embedded Please add you name to the attendee list and edit as needed. The next question is how do we keep the conversation going and how do we actually get the work done. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-43790 Fax: +49 721 608-46071 www.cel.kit.edu KIT -- University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association pgpDG3HtVLdfK.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Radio interoperability
Hi Bijendra, I'm under the expression that Wayne has already supplied you with the idea of the AM tx flowgraph; it's your project, clicking together the flowgraph after his description is up to you ;) Well, if you need full-duplex, you will need two independent RX and two independent TX radio interfaces, so you need to have two USRP sources, two USRP sinks, and connect everything correctly. Again: AM Rx will always be noisy as long as you don't do stunts on the analog/physical side of your receiver; I haven't had a look at your GRC files though, so is it possible you don't low pass your received signal? AM transmission seldom have a bandwidth significantly higher than 3kHz; this is partly because usually analog AM receivers have quite narrowband RF filters, to avoid picking up a lot of noise. Since this is totally anti-software defined radio, the LFRX doesn't have such filters. Get a filter, get a preamp, get a higher gain antenna. Do what you must do to get a cleaner signal. Happy hacking, Marcus On 10/10/2013 02:18 PM, Bijendra Singh wrote: Yes, you got it right. Its a military equipment. Both of them are tactical radios one for HF and another for VHF. And I am trying to use my GNU as a relay platform. So could you please help me out in getting those flowgraphs. I've already attached .grc files of FM tx and rx, but couldnt find AM tx, and a noisy rx. Now I have to integrate them with one another, ie HF and VHF. What I'm suppose to do now? On Thu, Oct 10, 2013 at 3:35 PM, Marcus Müller mar...@hostalia.de mailto:mar...@hostalia.de wrote: Hi Bijendra, I, too, am confused. So let's try to understand what you are doing here! On 10/10/2013 10:39 AM, Bijendra Singh wrote: Well it is a project I'm working on. I am trying to receive an AM signal from HF radio Yes, so receiving amplitude modulated audio on a carrier somewhere between 3MHz and 30Mhz (==HF) which will be provided in the usrp source in my gnu You want to capture that using a USRP and GNU Radio, I presume. and will transmit a FM signal as output Aaaaha! Second chain of operation! You want to simultaneously generate an FM signal in the usrp sink which I'm trying to send it to the VHF radio. And you want to transmit that using a USRP (the same USRP?) to another Radio receiver, that listens on a VHF carrier (30MHz-300MHz) then. And vice versa. Huh? Your radio receivers usually can't transmit, so that's confusing I'm using CNR-900 VHF radio which freq range is 30 to 89.899 MHz and RS-HX radio which freq range is 3 to 30 MHz. When I tried the hf2vhf.grc file, it is working, but with noise. Same thing will be possible for VHF to Hf, I guess. And I'm stuck in this. Any possible remedies?? OOh ok... this is military communications, and I was under the impression we're talking broadcast Radio stations. I must try to reunderstand now: You're trying to set up a relay station, for someone with some kind of HF AM tactical radio to communicate with someone with a VHF FM tactical radio, right? Anyway, Martin is right: Whatever you do, AM will always be noisy because it's AM, and unless you use laaarge antennas the HF signal on the USRP will most probably be strongly attenuated (1/2 wavelength of 30MHz is 5m...). So your SNR gets even worse. Greetings, Marcus On Thu, Oct 10, 2013 at 1:48 PM, Martin Braun (CEL) martin.br...@kit.edu mailto:martin.br...@kit.edu wrote: Hi Bijendra, it's not quite clear what your question is. A couple of things you might want to consider: - AM is per se noisy. A commercial HF receiver would also have much better filters than you can achieve with an LFRX-only setup, so expect much noise here - FM is much better with noise. - You're not supposed to rx AM signals with an FM receiver. - VHF and HF usually designate (separate) frequency ranges. So when talking about 'interoperability' between those, most people will be confused. Well, I am. MB On Thu, Oct 10, 2013 at 12:58:06PM +0530, Bijendra Singh wrote: Hello every one, I'm working on a college level project to show interoperability between HF and VHF radio using GNU radio. My aims are listed below: 1) To obtain FM transmitter and receiver waveform in GNU radio as flowgraph, so that i can communicate between laptop and VHF radio (In my case I'm using radio of the range 30-89.899 MHz) :- This I have already achieved 2)To obtain AM transmitter and receiver waveform in GNu radio as flowgraph, so that I can communicate between laptop and HF radio (In my case I'm using a HF radio of the range 3-30 MHz):- I was able to download a SSB receiver and it is functional but
Re: [Discuss-gnuradio] Summary of embedded working group at GRCON13
Excellent! Thanks for the link. - MLD On Oct 10, 2013, at 8:45 AM, Martin Braun (CEL) martin.br...@kit.edu wrote: Great idea! In fact, it's so good, it's already been implemented: http://gnuradio.org/redmine/projects/gnuradio/wiki/GRCon13WG ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Again bladerf / gqrx / gr-osmosdr
On Thu, Oct 10, 2013 at 1:52 AM, Ralph A. Schmid, dk5ras ra...@schmid.xxx wrote: Hi, Looks like there is something missing from your libbladeRF.so. The repository shows they were added on October 2nd. Are you sure you're building the latest stuff? Should be the latest, when doing a git pull right before building it. I did not yet delete the whole BladeRF folder and clone into a totally new folder, maybe this helps? I always recommend blowing away the build directory and rerunning cmake .., make, sudo make install. That is the best way I've found to make sure things are fresh. I just rebuilt against everything last night and things seemed fine to me. Others have also reported success. Let me know how it goes. Brian ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Question about extra header
I'm using the file_meta_sink to record time-stamped data, and I have a question about the implementation of this block. I currently call it in Python as follows: self.blocks_file_meta_sink_0 = blocks.file_meta_sink(gr.sizeof_short*2, self.dat_filename, samp_rate, 1, blocks.GR_FILE_SHORT, False, 2*int(samp_rate), , False) If I understand the parameters right, I have configured this block so as to not include extra header information. If I also understand correctly, there are (by default, if no extras) eight fields provided in the header. However, when I run my Python flowgraph and read the header information from the created file using gr_read_file_metadata.py, I get the following: HEADER 0 Version Number: 0 Sample Rate: 1000.00 sps Seconds: 1381406414.235846 Item size: 4 Data Type: short (1) Complex? False Header Length: 171 bytes Extra Length: 22 Extra Header? True Size of Data: 8000 bytes 2000 items Extra Header: rx_freq: 8.99e+08 As you can see, a ninth field is returned as an extra header, rx_freq. As far as I can tell in my flowgraph, I'm not doing anything myself that would cause this field to be added. I'd like to know where this field is added since I'd like to add more. Specifically I'd like to add a GPS string or two to tag location and velocity. I'm using a USRP N210 with GPSDO and querying the GPGGA, GPRMC, and XYZSP strings to get this information. I can currently parse these strings and write what I want from them to another file, but if I can contain it all in one file it would be easier for me to deal with off-line. Thanks, Scott Bennett JHU/APL ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Time synchronization between two USRPs without external signal
Hi, I have implemented time synchronization between two USRPs without GPSDO, MIMO cable or referring to computer's time.It's a sender-receiver method based on message exchange. It will be included in my next paper soon. I use the tx_time and tx_sob tag to transmit the message at the planned time. When this message researches the receiver, I can get the receive time via rx_time tags. The transmit and receive time of tx tags and rx tags are recorded in USRP motherboard without the jitter of Ethernet cable or operating system. So I think it could achieve the best accuracy without modifying FPGA. The experiment shows the accuracy is around 160us. I think it's mostly caused by the jitter of the tx tag's time. I wanna achieve better accuracy than this and the best way is adding a hardware timestamp module in FPGA. Is this way feasible? As for now, I wanna get a depth understanding of the implementing of tx tag,so I will know the accuracy limit of this method. But I'm not familiar with the FPGA, so could anyone describe how tx_time tag implemented or give me some documents about this? Thanks in advance. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Question over the Silder in GRC
Thanks, Martin. In fact, the event would be triggered as imagined. I want to know whether each in-between value during moving the slider would be sent to USRP, and the USRP would react to each value? Does the value have to hold on for some time before the event is triggered? Thanks, Baokun On Thu, Oct 10, 2013 at 4:03 AM, Martin Braun (CEL) martin.br...@kit.eduwrote: On Wed, Oct 09, 2013 at 05:15:04PM -0400, Baokun Liu wrote: Hi all, I am using USRP N210 and GRC. I have a question over changing a USRP parameter using a slider in GRC. If I want to change the TX frequency from 2GHz to 4GHz using a slider, as we know, during this process, the slider would experience many in-between values, such as 2.1, 3, 3.55, 3.888 and so on, how USRP would react to these in-between values? Is there some mechanism to prevent the USRP from overloaded if I move the slider very fast? Should the slider value hold on for some time before sending the value to USRP? Hi Baokun, haven't checked this, but are you sure the event doesn't get triggered once you let go of the slider? At least that's what I thought would happen. MB -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-43790 Fax: +49 721 608-46071 www.cel.kit.edu KIT -- University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association ___ 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
Re: [Discuss-gnuradio] Summary of embedded working group at GRCON13
Now that gnuradio.org is back up, we just need someone to populate the wiki page on coprocessors ... I think the chair was from Sandia National Labs .. don't remember his name now. I'll take a shot at this page in the next couple of days if nobody else gets there; quite a bit on my queue just right now. - MLD On Oct 10, 2013, at 9:00 AM, Michael Dickens michael.dick...@ettus.com wrote: Excellent! Thanks for the link. - MLD ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Summary of embedded working group at GRCON13
On Thu, Oct 10, 2013 at 10:17 AM, Michael Dickens michael.dick...@ettus.com wrote: Now that gnuradio.org is back up, we just need someone to populate the wiki page on coprocessors ... I think the chair was from Sandia National Labs .. don't remember his name now. I'll take a shot at this page in the next couple of days if nobody else gets there; quite a bit on my queue just right now. - MLD It's Justin Ford from SNL that was leading this group. He was in touch with me last night saying that he'd update the wiki soon. I'm actually going to take his slides that he presented in the wrap-up session right now and put them on that page for a start. The next big question is how is each GRWG going to be communicate with each other. The Wiki is the best place for more permanent ideas and documentation about each WG, but there needs to be a coordinated effort for communicating among the interested members. And it might not be the same solution for each of the WGs. This is a topic of next week's dev call if anyone wants to weigh in. Tom On Oct 10, 2013, at 9:00 AM, Michael Dickens michael.dick...@ettus.com wrote: Excellent! Thanks for the link. - MLD ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Question over the Silder in GRC
It sounds like when you say in between you mean the period of time from when the user stop dragging the slider and the next time they stop dragging the slider. In general, when people ask this question the area of focus is the period of time when they are dragging the slider. John ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Summary of embedded working group at GRCON13
On Thu, Oct 10, 2013 at 10:46 AM, Tom Rondeau t...@trondeau.com wrote: The next big question is how is each GRWG going to be communicate with each other. The Wiki is the best place for more permanent ideas and documentation about each WG, but there needs to be a coordinated effort for communicating among the interested members. And it might not be the same solution for each of the WGs. This is a topic of next week's dev call if anyone wants to weigh in. I've always found dedicated mailing lists ideal for special interest / working discussions. -Greg ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Bug in freq_xlating_fir_filter_XXX
On Wed, Oct 9, 2013 at 11:01 PM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
I attach the patch for this correction
(for some reason I cannot git push...)
Achilleas
Sorry for the delay getting back to you. I walked through the math
myself but couldn't find where you were wrong, but I knew this patch
changed the sign of frequency translation. Just try it with a sine
wave a 1 kHz and set the Center Frequency to 1 kHz. The signal out is
not at 2 kHz.
Turns out we were both missing something. This just spins the filter
from baseband to bandpass around fwT0, but there's still the rotator
(d_r) that is responsible for spinning the output down.
Basically, we're changing x(t) - (mult by -fwT0) - LPF - y(t)
Into: x(t) - BPF - (mult by fwT0) - y(t)
(The block is also taking into account downsampling that's not
accounted for above such that we downsample in the filter before down
shifting in frequency.)
So this, I think, is the correct patch:
diff --git a/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
b/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
index 72a2c05..f3c8ffd 100644
--- a/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
+++ b/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
@@ -77,14 +77,15 @@ namespace gr {
{
std::vectorgr_complex ctaps(d_proto_taps.size());
- float fwT0 = -2 * M_PI * d_center_freq / d_sampling_freq;
+ //float fwT0 = -2 * M_PI * d_center_freq / d_sampling_freq;
+ float fwT0 = 2 * M_PI * d_center_freq / d_sampling_freq;
for(unsigned int i = 0; i d_proto_taps.size(); i++) {
ctaps[i] = d_proto_taps[i] * exp(gr_complex(0, i * fwT0));
}
- std::reverse(ctaps.begin(), ctaps.end());
+ //std::reverse(ctaps.begin(), ctaps.end());
d_composite_fir-set_taps(ctaps);
- d_r.set_phase_incr(exp(gr_complex(0, fwT0 * decimation(;
+ d_r.set_phase_incr(exp(gr_complex(0, -fwT0 * decimation(;
}
void
Tom
On Wed, Oct 9, 2013 at 12:59 PM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
Maybe I am wrong, but here is the idea:
the original taps are taps.
then inside the freq_xlating filter new combined taps are generated
as follows
comb_t = taps_t *exp(-j A t)
then the COMBINED filter is reversed.
The effect of that is that essentially we have the filter
reversed_t = taps_{-t} *exp( + j A t)
If we drop the reversing part from the process (commenting out one line of
code) we will end up
with the filter nonreversed with
nonrevered_t = comb_t = taps_t *exp(-j A t)
Comparing the reveresed and non-reversed we see that even when taps are
symmetric, the frequency sign gas changed so we need to change it back!
let me know if i am missing something,
Achilleas
On Wed, Oct 9, 2013 at 11:02 AM, Tom Rondeau t...@trondeau.com wrote:
On Wed, Oct 9, 2013 at 10:45 AM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
I will submit the patch.
regarding the sign change in frequency, I didn't mean to change the
convention:
the sign change IS REQUIRED in order to KEEP the convention because now
the taps are not reversed...
Achilleas
Sorry, Achilleas, I'm not seeing it. In the common case of a symmetric
FIR filter, the reverse function doesn't change any behavior, but the
minus sine definitely does.
I don't see how reversing the order of the filter taps and changing
the sign have anything to do with each other.
Tom
On Wed, Oct 9, 2013 at 9:20 AM, Tom Rondeau t...@trondeau.com wrote:
On Tue, Oct 8, 2013 at 9:39 PM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
I was playing around with
fir_filter_XXX
and
freq_xlating_fir_filter_XXX
and noticed that the two do not give the same output
for the same input (and center_freq=0 in the xlating filter).
Looking at the implementation of the latter
it is obvious why: the taps are reversed in the line:
std::reverse(ctaps.begin(), ctaps.end());
For consistency the taps should not be reversed (as in all other
filters)
We also need to set
Yes, please submit a patch for this. The taps are reversed inside the
fir filters, so this is redundant and confusing. Most people probably
use symmetric filter taps, which is why it has not been found.
float fwT0 = 2 * M_PI * d_center_freq / d_sampling_freq;
(instead of the minus sign in the code).
unless there is an objection, I will go ahead and push a correction,
Achilleas
Don't change the sign of the frequency. I know this is controversial,
but from my experience with users, more people find the current way
easier to understand. We're telling the filter what the center
frequency is, which means that we will take a signal at Fc and
downshift it to DC. To me, if we're on carrier Fc and we specify -Fc
as the Center Frequency, that's more confusing.
Tom
___
Discuss-gnuradio mailing list
Re: [Discuss-gnuradio] controlling flowgraph
Ok, I have found button :), but the problem is now following. Part of my script looks like this: def aaa(a): global state state = 1 state = 1 data = [0] if __name__ == '__main__': parser = OptionParser(option_class=eng_option, usage=%prog: [options]) (options, args) = parser.parse_args() tb = top_block() while(True): if state == 1: print aa state = 0 data.append(0) tb.blocks_vector_source_x_0.set_data(data) tb.run() print tb.blocks_vector_sink_x_0.data() aaa is callback function called when the button is pressed. What i want to achieve is following: when flowgraph starts i don't want any transmiton, I just want to see gui. when i press the button, then one frame should be sent. when i press again the button another frame should be sent. ... Is this possible? In example above I don't see gui at all. On Thu, Oct 10, 2013 at 12:40 PM, Nemanja Savic vlasi...@gmail.com wrote: Hi all guys, I wanted to implement a ask transmitter and a button for triggering transmition of a single frame of data. My idea was to do that with a sort of state machine and a button, but as far as i can see there is no button in wx gui blocks. How do uo usually do this? Many thanks, -- Nemanja Savić -- Nemanja Savić ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Bug in freq_xlating_fir_filter_XXX
I stand corrected.
Everything works fine with the new patch now!
thanks for the help,
Achilleas
On Thu, Oct 10, 2013 at 11:22 AM, Tom Rondeau t...@trondeau.com wrote:
On Wed, Oct 9, 2013 at 11:01 PM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
I attach the patch for this correction
(for some reason I cannot git push...)
Achilleas
Sorry for the delay getting back to you. I walked through the math
myself but couldn't find where you were wrong, but I knew this patch
changed the sign of frequency translation. Just try it with a sine
wave a 1 kHz and set the Center Frequency to 1 kHz. The signal out is
not at 2 kHz.
Turns out we were both missing something. This just spins the filter
from baseband to bandpass around fwT0, but there's still the rotator
(d_r) that is responsible for spinning the output down.
Basically, we're changing x(t) - (mult by -fwT0) - LPF - y(t)
Into: x(t) - BPF - (mult by fwT0) - y(t)
(The block is also taking into account downsampling that's not
accounted for above such that we downsample in the filter before down
shifting in frequency.)
So this, I think, is the correct patch:
diff --git a/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
b/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
index 72a2c05..f3c8ffd 100644
--- a/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
+++ b/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
@@ -77,14 +77,15 @@ namespace gr {
{
std::vectorgr_complex ctaps(d_proto_taps.size());
- float fwT0 = -2 * M_PI * d_center_freq / d_sampling_freq;
+ //float fwT0 = -2 * M_PI * d_center_freq / d_sampling_freq;
+ float fwT0 = 2 * M_PI * d_center_freq / d_sampling_freq;
for(unsigned int i = 0; i d_proto_taps.size(); i++) {
ctaps[i] = d_proto_taps[i] * exp(gr_complex(0, i * fwT0));
}
- std::reverse(ctaps.begin(), ctaps.end());
+ //std::reverse(ctaps.begin(), ctaps.end());
d_composite_fir-set_taps(ctaps);
- d_r.set_phase_incr(exp(gr_complex(0, fwT0 * decimation(;
+ d_r.set_phase_incr(exp(gr_complex(0, -fwT0 * decimation(;
}
void
Tom
On Wed, Oct 9, 2013 at 12:59 PM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
Maybe I am wrong, but here is the idea:
the original taps are taps.
then inside the freq_xlating filter new combined taps are generated
as follows
comb_t = taps_t *exp(-j A t)
then the COMBINED filter is reversed.
The effect of that is that essentially we have the filter
reversed_t = taps_{-t} *exp( + j A t)
If we drop the reversing part from the process (commenting out one line
of
code) we will end up
with the filter nonreversed with
nonrevered_t = comb_t = taps_t *exp(-j A t)
Comparing the reveresed and non-reversed we see that even when taps are
symmetric, the frequency sign gas changed so we need to change it back!
let me know if i am missing something,
Achilleas
On Wed, Oct 9, 2013 at 11:02 AM, Tom Rondeau t...@trondeau.com wrote:
On Wed, Oct 9, 2013 at 10:45 AM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
I will submit the patch.
regarding the sign change in frequency, I didn't mean to change the
convention:
the sign change IS REQUIRED in order to KEEP the convention because
now
the taps are not reversed...
Achilleas
Sorry, Achilleas, I'm not seeing it. In the common case of a symmetric
FIR filter, the reverse function doesn't change any behavior, but the
minus sine definitely does.
I don't see how reversing the order of the filter taps and changing
the sign have anything to do with each other.
Tom
On Wed, Oct 9, 2013 at 9:20 AM, Tom Rondeau t...@trondeau.com
wrote:
On Tue, Oct 8, 2013 at 9:39 PM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
I was playing around with
fir_filter_XXX
and
freq_xlating_fir_filter_XXX
and noticed that the two do not give the same output
for the same input (and center_freq=0 in the xlating filter).
Looking at the implementation of the latter
it is obvious why: the taps are reversed in the line:
std::reverse(ctaps.begin(), ctaps.end());
For consistency the taps should not be reversed (as in all other
filters)
We also need to set
Yes, please submit a patch for this. The taps are reversed inside
the
fir filters, so this is redundant and confusing. Most people
probably
use symmetric filter taps, which is why it has not been found.
float fwT0 = 2 * M_PI * d_center_freq / d_sampling_freq;
(instead of the minus sign in the code).
unless there is an objection, I will go ahead and push a
correction,
Achilleas
Don't change the sign of the frequency. I know this is
controversial,
but from my experience with users, more people find the current way
easier to understand. We're telling the filter
Re: [Discuss-gnuradio] Question over the Silder in GRC
Trying to figure that out, I went and had a look at the source code of the wxgui slider. In fact, it had a demo mode that could be accessed when just calling the python file as main: $python gr-wxgui/python/wxgui/slider.py However, that was broken, so I fixed it; pull request against master has been sent. Using the repaired demo I was able to find out that intermediate values are given at random intermediate points, so changing a slider from its minimum to its maximum as fast as possible yields a (seemingly) random selection of values in between. Greetings, Marcus On 10/10/2013 03:53 PM, Baokun Liu wrote: Thanks, Martin. In fact, the event would be triggered as imagined. I want to know whether each in-between value during moving the slider would be sent to USRP, and the USRP would react to each value? Does the value have to hold on for some time before the event is triggered? Thanks, Baokun On Thu, Oct 10, 2013 at 4:03 AM, Martin Braun (CEL) martin.br...@kit.edu mailto:martin.br...@kit.edu wrote: On Wed, Oct 09, 2013 at 05:15:04PM -0400, Baokun Liu wrote: Hi all, I am using USRP N210 and GRC. I have a question over changing a USRP parameter using a slider in GRC. If I want to change the TX frequency from 2GHz to 4GHz using a slider, as we know, during this process, the slider would experience many in-between values, such as 2.1, 3, 3.55, 3.888 and so on, how USRP would react to these in-between values? Is there some mechanism to prevent the USRP from overloaded if I move the slider very fast? Should the slider value hold on for some time before sending the value to USRP? Hi Baokun, haven't checked this, but are you sure the event doesn't get triggered once you let go of the slider? At least that's what I thought would happen. MB -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-43790 tel:%2B49%20721%20608-43790 Fax: +49 721 608-46071 tel:%2B49%20721%20608-46071 www.cel.kit.edu http://www.cel.kit.edu KIT -- University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org mailto: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 list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Bug in freq_xlating_fir_filter_XXX
On Thu, Oct 10, 2013 at 11:53 AM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
I stand corrected.
Everything works fine with the new patch now!
thanks for the help,
Achilleas
Ok, updated, tested (with updated and improved QA code) and pushed.
Also added a bit of an explanation to the build_composite_fir (as per
Ben Hilburn's blog post from the other day).
Thanks for pointing this out!
Tom
On Thu, Oct 10, 2013 at 11:22 AM, Tom Rondeau t...@trondeau.com wrote:
On Wed, Oct 9, 2013 at 11:01 PM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
I attach the patch for this correction
(for some reason I cannot git push...)
Achilleas
Sorry for the delay getting back to you. I walked through the math
myself but couldn't find where you were wrong, but I knew this patch
changed the sign of frequency translation. Just try it with a sine
wave a 1 kHz and set the Center Frequency to 1 kHz. The signal out is
not at 2 kHz.
Turns out we were both missing something. This just spins the filter
from baseband to bandpass around fwT0, but there's still the rotator
(d_r) that is responsible for spinning the output down.
Basically, we're changing x(t) - (mult by -fwT0) - LPF - y(t)
Into: x(t) - BPF - (mult by fwT0) - y(t)
(The block is also taking into account downsampling that's not
accounted for above such that we downsample in the filter before down
shifting in frequency.)
So this, I think, is the correct patch:
diff --git a/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
b/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
index 72a2c05..f3c8ffd 100644
--- a/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
+++ b/gr-filter/lib/freq_xlating_fir_filter_XXX_impl.cc.t
@@ -77,14 +77,15 @@ namespace gr {
{
std::vectorgr_complex ctaps(d_proto_taps.size());
- float fwT0 = -2 * M_PI * d_center_freq / d_sampling_freq;
+ //float fwT0 = -2 * M_PI * d_center_freq / d_sampling_freq;
+ float fwT0 = 2 * M_PI * d_center_freq / d_sampling_freq;
for(unsigned int i = 0; i d_proto_taps.size(); i++) {
ctaps[i] = d_proto_taps[i] * exp(gr_complex(0, i * fwT0));
}
- std::reverse(ctaps.begin(), ctaps.end());
+ //std::reverse(ctaps.begin(), ctaps.end());
d_composite_fir-set_taps(ctaps);
- d_r.set_phase_incr(exp(gr_complex(0, fwT0 * decimation(;
+ d_r.set_phase_incr(exp(gr_complex(0, -fwT0 * decimation(;
}
void
Tom
On Wed, Oct 9, 2013 at 12:59 PM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
Maybe I am wrong, but here is the idea:
the original taps are taps.
then inside the freq_xlating filter new combined taps are generated
as follows
comb_t = taps_t *exp(-j A t)
then the COMBINED filter is reversed.
The effect of that is that essentially we have the filter
reversed_t = taps_{-t} *exp( + j A t)
If we drop the reversing part from the process (commenting out one line
of
code) we will end up
with the filter nonreversed with
nonrevered_t = comb_t = taps_t *exp(-j A t)
Comparing the reveresed and non-reversed we see that even when taps are
symmetric, the frequency sign gas changed so we need to change it back!
let me know if i am missing something,
Achilleas
On Wed, Oct 9, 2013 at 11:02 AM, Tom Rondeau t...@trondeau.com wrote:
On Wed, Oct 9, 2013 at 10:45 AM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
I will submit the patch.
regarding the sign change in frequency, I didn't mean to change the
convention:
the sign change IS REQUIRED in order to KEEP the convention because
now
the taps are not reversed...
Achilleas
Sorry, Achilleas, I'm not seeing it. In the common case of a symmetric
FIR filter, the reverse function doesn't change any behavior, but the
minus sine definitely does.
I don't see how reversing the order of the filter taps and changing
the sign have anything to do with each other.
Tom
On Wed, Oct 9, 2013 at 9:20 AM, Tom Rondeau t...@trondeau.com
wrote:
On Tue, Oct 8, 2013 at 9:39 PM, Achilleas Anastasopoulos
anas...@umich.edu wrote:
I was playing around with
fir_filter_XXX
and
freq_xlating_fir_filter_XXX
and noticed that the two do not give the same output
for the same input (and center_freq=0 in the xlating filter).
Looking at the implementation of the latter
it is obvious why: the taps are reversed in the line:
std::reverse(ctaps.begin(), ctaps.end());
For consistency the taps should not be reversed (as in all other
filters)
We also need to set
Yes, please submit a patch for this. The taps are reversed inside
the
fir filters, so this is redundant and confusing. Most people
probably
use symmetric filter taps, which is why it has not been found.
float fwT0 = 2 * M_PI * d_center_freq / d_sampling_freq;
(instead of
Re: [Discuss-gnuradio] Again bladerf / gqrx / gr-osmosdr
It stays the same, after uninstalling everything, pulling fresh repos, building and installing bladeref, gr-osmosdr and gqrx in this order the message when building gqrx remains /usr/local/lib/libgnuradio-osmosdr.so: undefined reference to `bladerf_fpga_version' /usr/local/lib/libgnuradio-osmosdr.so: undefined reference to `bladerf_fw_version' collect2: ld returned 1 exit status make: *** [gqrx] Error 1 ras@ubuntu:~/gqrx$ Ralph. -Original Message- From: Brian Padalino [mailto:bpadal...@gmail.com] Sent: Thursday, 10 October, 2013 15:38 To: Ralph A. Schmid, dk5ras Cc: Alexandru Csete; GNURadio Discussion List Subject: Re: [Discuss-gnuradio] Again bladerf / gqrx / gr-osmosdr On Thu, Oct 10, 2013 at 1:52 AM, Ralph A. Schmid, dk5ras ra...@schmid.xxx wrote: Hi, Looks like there is something missing from your libbladeRF.so. The repository shows they were added on October 2nd. Are you sure you're building the latest stuff? Should be the latest, when doing a git pull right before building it. I did not yet delete the whole BladeRF folder and clone into a totally new folder, maybe this helps? I always recommend blowing away the build directory and rerunning cmake .., make, sudo make install. That is the best way I've found to make sure things are fresh. I just rebuilt against everything last night and things seemed fine to me. Others have also reported success. Let me know how it goes. Brian ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Async Packet Transmission with Unmodulated Carrier
I am attempting to transmit asynchronous packets in a precise manor using time tags, and at the same time transmit an unmodulated carrier while there are no packets being sent. I am considering disconnecting the USRP sink from the packet path and connecting it to a signal source, however there are questions of timing involved with knowing when to do this reconnection. This design is to digitally phase modulate the carrier of an AM signal and therefore cannot have gaps in the carrier signal. I am wondering how this all would work with time tagged data and the unmodulated carrier, or would these two processes interfere with one another? Also, if it could work, does anybody have any suggestions as to how it should be implemented? Thank you in advance for any assistance, Michael Berman ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Again bladerf / gqrx / gr-osmosdr
Those look a lot like some errors I was getting a short while ago. They popped up while the compiler was at the linking stage. My errors were in the CMakeList.txt files, which were somewhat opaque to me. By elimination, can you verify that gnuradio can access your bladerf directly? Say a source to an fft plot, tuned to a local FM radio station? Jared On Oct 10, 2013 11:13 AM, Ralph A. Schmid, dk5ras ra...@schmid.xxx wrote: It stays the same, after uninstalling everything, pulling fresh repos, building and installing bladeref, gr-osmosdr and gqrx in this order the message when building gqrx remains /usr/local/lib/libgnuradio-osmosdr.so: undefined reference to `bladerf_fpga_version' /usr/local/lib/libgnuradio-osmosdr.so: undefined reference to `bladerf_fw_version' collect2: ld returned 1 exit status make: *** [gqrx] Error 1 ras@ubuntu:~/gqrx$ Ralph. -Original Message- From: Brian Padalino [mailto:bpadal...@gmail.com] Sent: Thursday, 10 October, 2013 15:38 To: Ralph A. Schmid, dk5ras Cc: Alexandru Csete; GNURadio Discussion List Subject: Re: [Discuss-gnuradio] Again bladerf / gqrx / gr-osmosdr On Thu, Oct 10, 2013 at 1:52 AM, Ralph A. Schmid, dk5ras ra...@schmid.xxx wrote: Hi, Looks like there is something missing from your libbladeRF.so. The repository shows they were added on October 2nd. Are you sure you're building the latest stuff? Should be the latest, when doing a git pull right before building it. I did not yet delete the whole BladeRF folder and clone into a totally new folder, maybe this helps? I always recommend blowing away the build directory and rerunning cmake .., make, sudo make install. That is the best way I've found to make sure things are fresh. I just rebuilt against everything last night and things seemed fine to me. Others have also reported success. Let me know how it goes. Brian ___ 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] (no subject)
Hello everyone, Now I understand why most of the people get confused with the previous topic I'm talking about. By radio I mean tactical radio for communication, use in military communication. So my Question is, Is it possible to integrate AM tx waveform with FM rx waveform as a working flowgraph in GNU and vice versa. If yes, how can I achieve this?? ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Costas loop lock?
I am using a Costas loop for carrier recovery with QAM16 data. The carrier is only 2khz. The I/Q output of the Costas loop seems to track (the original sin/cos of the modulating carrier's Frequency Phase) steadily for a long period (minutes) and then the Phase moves off, normally in +/- 45 or 90 degrees in one or both of the phases. Any thoughts on why this occurs or how I can fix this issue? Thanks...Tom___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Question about extra header
On Thu, Oct 10, 2013 at 9:39 AM, Bennett, David S. (Scott) scott.benn...@jhuapl.edu wrote: I’m using the file_meta_sink to record time-stamped data, and I have a question about the implementation of this block. I currently call it in Python as follows: self.blocks_file_meta_sink_0 = blocks.file_meta_sink(gr.sizeof_short*2, self.dat_filename, samp_rate, 1, blocks.GR_FILE_SHORT, False, 2*int(samp_rate), , False) If I understand the parameters right, I have configured this block so as to not include extra header information. If I also understand correctly, there are (by default, if no extras) eight fields provided in the header. However, when I run my Python flowgraph and read the header information from the created file using gr_read_file_metadata.py, I get the following: HEADER 0 Version Number: 0 Sample Rate: 1000.00 sps Seconds: 1381406414.235846 Item size: 4 Data Type: short (1) Complex? False Header Length: 171 bytes Extra Length: 22 Extra Header? True Size of Data: 8000 bytes 2000 items Extra Header: rx_freq: 8.99e+08 As you can see, a ninth field is returned as an extra header, rx_freq. As far as I can tell in my flowgraph, I’m not doing anything myself that would cause this field to be added. I’d like to know where this field is added since I’d like to add more. Specifically I’d like to add a GPS string or two to tag location and velocity. I’m using a USRP N210 with GPSDO and querying the GPGGA, GPRMC, and XYZSP strings to get this information. I can currently parse these strings and write what I want from them to another file, but if I can contain it all in one file it would be easier for me to deal with off-line. Thanks, Scott Bennett JHU/APL The extra_dict argument to the constructor is just a way to add more data to the extra part of the header; any more data you want to add that wouldn't be in there normally. The extra part of the header collects any tags observed, so the USRP will generate tags like rx_freq that will go into the header. The metadata section of the manual has a pretty good explanation of how it works: http://gnuradio.org/doc/doxygen/page_metadata.html Tom ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Again bladerf / gqrx / gr-osmosdr
What is directly? J At least I can use it before updating all this stuff, GR can RX and TX just fine, but through GR-osmosdr. It looks to me that osmosdr may be the deeper involved in the problem, when not updating this one nothing wrong is happening. At the moment I am on latest revision with bladerf and gqrx, gqrx works, gnuradio works. Just updating gr-osmosdr will break things. Ralph. From: Jared Clements [mailto:jared.cleme...@gmail.com] Sent: Friday, 11 October, 2013 02:21 To: Ralph A. Schmid, dk5ras Cc: GNURadio Discussion List; Brian Padalino Subject: Re: [Discuss-gnuradio] Again bladerf / gqrx / gr-osmosdr Those look a lot like some errors I was getting a short while ago. They popped up while the compiler was at the linking stage. My errors were in the CMakeList.txt files, which were somewhat opaque to me. By elimination, can you verify that gnuradio can access your bladerf directly? Say a source to an fft plot, tuned to a local FM radio station? Jared On Oct 10, 2013 11:13 AM, Ralph A. Schmid, dk5ras ra...@schmid.xxx wrote: It stays the same, after uninstalling everything, pulling fresh repos, building and installing bladeref, gr-osmosdr and gqrx in this order the message when building gqrx remains /usr/local/lib/libgnuradio-osmosdr.so: undefined reference to `bladerf_fpga_version' /usr/local/lib/libgnuradio-osmosdr.so: undefined reference to `bladerf_fw_version' collect2: ld returned 1 exit status make: *** [gqrx] Error 1 ras@ubuntu:~/gqrx$ Ralph. -Original Message- From: Brian Padalino [mailto:bpadal...@gmail.com] Sent: Thursday, 10 October, 2013 15:38 To: Ralph A. Schmid, dk5ras Cc: Alexandru Csete; GNURadio Discussion List Subject: Re: [Discuss-gnuradio] Again bladerf / gqrx / gr-osmosdr On Thu, Oct 10, 2013 at 1:52 AM, Ralph A. Schmid, dk5ras ra...@schmid.xxx wrote: Hi, Looks like there is something missing from your libbladeRF.so. The repository shows they were added on October 2nd. Are you sure you're building the latest stuff? Should be the latest, when doing a git pull right before building it. I did not yet delete the whole BladeRF folder and clone into a totally new folder, maybe this helps? I always recommend blowing away the build directory and rerunning cmake .., make, sudo make install. That is the best way I've found to make sure things are fresh. I just rebuilt against everything last night and things seemed fine to me. Others have also reported success. Let me know how it goes. Brian ___ 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
