Re: [Discuss-gnuradio] usrp_spectrum_sense.py FFT bin values are all zero.
The frequency band ranges from 470MHz to 806MHz, each channel's frequency band is 8MHz, so we have 42 channels in total. Channel 1,3,5,7 are analog channels, others are digital channels. I want to set the value of parameters in usrp_spectrum_sense.py as follows: fft-size: 2048 channel-bandwidth:8e6 samp-rate:12.5e6 freq_step: 8e6. dwell-delay:0.5 tune-delay:0.5 I experiment with ./usrp_spectrum_sense.py Then for each channel, we have 2048 bins, which can be used to calculate each channel's power(in dB). Am I right? On Mon, Apr 8, 2013 at 12:38 AM, Mike Jameson m...@scanoo.com wrote: Hi, For your application, please experiment with the following command: ./usrp_spectrum_sense.py -A TX/RX --fft-size=25 --samp-rate=25e6 --gain=15 --dwell-delay=0.25 --tune-delay=0.25 --channel-bandwidth=8e6 470e6 800e6 Note that 'freq_step' should remain unchanged at '0.75 * usrp_rate' in the script to make sure signals at the edge of the incoming front-end signal bandwidth (25MHz) are not missed. Mike -- Mike Jameson M0MIK BSc Email: m...@scanoo.com Web: http://scanoo.com On 7 April 2013 17:22, Jincheng Zhang perfume0...@gmail.com wrote: Thanks Mike. I'm a little confused. The parameters are listed as follows: sample-rate: channel-bandwidth: freq_step: fft_size: You mean that I should set sample-rate be 25e6, channel-bandwidth be 8e6, freq_step be 8e6 and fft_size be 25? If we set the fft-size be 25, then which 8 bins I should select to calculate the power? By the way, since the magnitude of FFT bin is decimal, maybe I should change the magnitude of FFT bin values to mw and add the 8 bins, and then transfer to decimal again? Since we cannot straightly add the FFT bin values in decimal. By the way, how about the self.connect, should I add the log parameter to it? Thanks. Hope for your reply. On Mon, Apr 8, 2013 at 12:11 AM, Mike Jameson m...@scanoo.com wrote: Hi Jincheng, Try setting the UHD sample rate to 25e6 and the number of fft bins to 25 which will give you 1e6 Hz per bin. Adding up the magnitude of 8 bins (1MHz * 8 = 8MHz) will therefore give you the wanted channel power in decimal format (magnitude). In case you are confused, I recently updated usrp_spectrum_sense.py to include a --channel-bandwidth setting which rounds up the frequency displayed to the nearest frequency. I'm working on making it cleaner by adjusting the fft size to match the wanted channel. In the meantime, set '--channel-bandwidth=8e6' to make the frequency round to the nearest 8MHz frequency. Hope that helps, Mike -- Mike Jameson M0MIK BSc Email: m...@scanoo.com Web: http://scanoo.com On 7 April 2013 16:23, Jincheng Zhang perfume0...@gmail.com wrote: I want to use usrp_spectrum_sense.py to sweep the Hong Kong TV band which ranges from 470MHz to 806MHz and get every channel's power in dB. Each channel's frequency band is 8MHz. Now I'm using USRP2 with TVRX2 daughter board. I have installed the latest gnuraio and uhd. But when I use the usrp_spectrum_sense.py to get the power of each channel, some FFT bin values are extremely big. In particular, I'm not sure abou the self.connect(self.u, s2v, fft, c2mag, stats). It doesn't take log as the parameter, FFT size is 2048, sample-rate is 12.5MHz(to let the decimation be 8M), freq_step is 8MHz. Anyone has any ideas about how to use usrp_spectrum_sense.py to calculate each channel's power? On Sun, Apr 7, 2013 at 8:24 PM, Jincheng Zhang perfume0...@gmail.comwrote: Hi, all, I use the usrp_spectrum_sense.py to sweep the TV band from 470MHz to 806MHz. But when I use self.connect(self.u, s2v, fft, c2mag, log, stats), the FFT bin values I got are all zero. Also, what's the magnitude of FFT bin value? Thanks. -- Best regards, Jincheng Zhang -- Best regards, Jincheng Zhang Department of Information Engineering The Chinese University of Hong Kong http://personal.ie.cuhk.edu.hk/~zj012/ http://www.jxqc.org/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- Best regards, Jincheng Zhang Department of Information Engineering The Chinese University of Hong Kong http://personal.ie.cuhk.edu.hk/~zj012/ http://www.jxqc.org/ -- Best regards, Jincheng Zhang Department of Information Engineering The Chinese University of Hong Kong http://personal.ie.cuhk.edu.hk/~zj012/ http://www.jxqc.org/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] How many preambles uesd in ofdm example for frame synchronization, 10 short preambles ?
On Sun, Apr 07, 2013 at 11:49:14AM +0800, Yingjie Chen wrote: Thanks for your reply. I still have one question. I try to plot the peak detection data to observe the the shape of the peak, which seems like a plateau(square wave).I have done a simulation before in matlab. If only one preamble exist, when the 1st half of the preamble correlate with 2nd half, the shape of peak should be much sharper(like a triangle), because the repeated pattern is not enough. My question is : If gunradio only use one preamble with 2 repeated pattern, the shape of the peak should look like a triangle rather than a plateau, is that right? No, the plateau is correct. Since your correlation window is 2x half of 1 symbol, the cyclic prefix will increase your peak (in AWGN channels to the length of the cyclic prefix). 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 pgpBzymc2G9tY.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] SNR estimation in ofdm using preamble symbol
On Sat, Apr 06, 2013 at 10:58:31AM -0500, Nathan West wrote: On Saturday, April 6, 2013, Pradeep Borado wrote: HI , i am doing a project on channel estimation in ofdm . I want to estimate the SNR of the recievd symbol using the preamble symbol. Please let me if i can do this in GNU radio. http://gnuradio.org/doc/doxygen/group__snr__blk.html Tom created and blogged about two blocks to do SNR. I've had success using both for PSK signals. One is a probe that generates messages. The other is a pass through that generates tags. This will indeed work if you serialize the frames into complex symbols, but only if you have a flat fading channel! You could also use the preamble, but will have to write your own block for that since the preamble is discarded on reception in the current GNU Radio blocks. Estimating SNR for OFDM is marginally different than for single-carrier. I suggest having a look at academic papers on this subject. 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 pgp0XP17wBIBj.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] how to Sense the spectrum bycomparing calculated energy with threshold
hi,i am working on the project spectrum sensing by using energy detection. first i insert a block of usrp then i insert the block of stream to vector ,then i have taken fft of that and then i have taken the magnitude square block.i yhs way i calaculte energy.now i have to compare this energy with predetermined threshold.so what is easier way to compare energy with threshold in order to sense the spectrum ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Alamouti code
Has there been an implementation of alamouti code for a 2*1 mimo setup. Any ideas to get started on implementing it. -- Regards Karan Talasila ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] (no subject)
-- Regards Karan Talasila ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Alamouti code
HI Has there been any implementation of alamouti code on gnuradio for a 2*1 mimo setup. Any ideas or references to get started on it. -- Regards Karan Talasila ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] how to Sense the spectrum bycomparing calculated energy with threshold
Hi, Omer, That's exactly what I want to do. But I use the usrp_spectrum_sense.py to get each channel's power and then compare with the threshold. Maybe you should try the usrp_spectrum_sense.py. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Please add me as a contributor
Tom asked me to open a ticket in thread: Out-of-tree module build fails for lack of Doxygen, despite -DENABLE_DOXYGEN=OFF. My Wiki account is 'tmonahan'. Someone please recite the required incantations. Thanks in advance, Tim Monahan-Mitchell ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Adding a custom modulation
Date: Sun, 7 Apr 2013 22:00:40 -0500 Subject: Re: [Discuss-gnuradio] Adding a custom modulation From: nathan.w...@okstate.edu To: felia...@live.cn CC: discuss-gnuradio@gnu.org On Sun, Apr 7, 2013 at 8:00 PM, 连非儿 felia...@live.cnmailto:felia...@live.cn wrote: Hi. I am testing my custom modulation scheme ppm.py. I followed this post http://lists.gnu.org/archive/html/discuss-gnuradio/2010-12/msg00265.html to register this modulation into mods/demods. I added a line import ppm in my benchmark_tx.py. I also tried placing the ppm.py file in blks2impl directory. However neither method worked. The result from print digital.modulation_utils.type_1_mods() did not contain ppm. Another issue is that I modified digital_constellation.cc, and I called functions in the modified digital_constellation.cc in my ppm.py. In this case should I rebuild gnuradio? If not, what should I do? Any suggestions? Thanks! Fei Hi Fei, The issue is that in the directory benchmark scripts are in isn't aware of your ppm file. You have a few options that you can explore by searching around for python import path or search path. and doing some reading. You can take a look in gr-digital/python/__init__.py to see how the other mod/demods are imported. Adding a line in that file from ppm import * should make your ppm stuff show up in Python after rebuilding gnuradio. And yes, you should rebuild gnuradio. Any time you change C++ source code you must rebuild it. -Nathan Hi Nathan, I've made my ppm a usable module in digital after rebuild. Thanks for your help! Fei ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Bandpass spectral correction
I have a need to have a *very flat* passband for some of the analysis I'm doing of neutral hydrogen. Real hardware, of course, produces passbands that aren't quite flat--some worse than others. So, I've tried an experiment in one of my flow-graphs where I take the (aggressively-averaged) FFT magnitudes by taking each bin magnitude and dividing by the maximum, and then using the inverse of that to produce a correction curve, as normalized magnitudes. I then use those normalized magnitudes in an FFT filter (after converting into time-domain), and the result works less-well than I would expect. The result is a *much-flatter* spectrum, but at the fine-scales I'm doing analysis at (0.5dB), it's not nearly as flat -- the outer edges are under-corrected, and the inner bits are over-corrected. Anybody have any pointers to good papers on passband flattening techniques? ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] GNU Radio in Brazil
Hi everyone. I'm traveling in Sao Paulo this week for NI Days Brasil ( http://brasil.ni.com/nidays ), and I have some free time. If you would like to get together to talk about GNU Radio and USRPs, what is coming from Ettus Research, or anything else SDR, send me an email. If you have a group and some space on Friday, I can even do a presentation and show you a cool prototype system we've been working on. Muito obrigado, Matt ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Increase min output buffer size (python block)
Hi all, I am currently working on my DRM receiver and have written a python block that returns either 0 or 3200 samples. Everything works fine as long as I do not connect its output to another custom python block that consumes only 1280 samples per call to general_work(). Both blocks are general blocks. Now I get this error message: File /usr/local/lib/python2.7/dist-packages/drmrx/freq_sync_py.py, line 120, in general_work out[:self.nfft] = self.correct_freq_offset(in0[:self.nfft]) ValueError: operands could not be broadcast together with shapes (1791) (3200) thread[thread-per-block[10]: gr_block freq_sync_py (23)]: caught unrecognized exception If I understand that correctly, the output buffer of the first block is too small and therefore cannot take all the samples I'd like to return. I tried to call top_block.drmrx_freq_sync_py_0.set_min_output_buffer(3200) in the python file generated by GRC but it gave me another error: tb.drmrx_freq_sync_py_0.set_min_output_buffer(3200) AttributeError: 'freq_sync_py' object has no attribute 'set_min_output_buffer' Is there a possibility to solve this problem or do I have to find an alternative solution, e. g. creating an internal buffer? Best regards Felix Wunsch ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Increase min output buffer size (python block)
tb.drmrx_freq_sync_py_0.set_min_output_buffer(3200) AttributeError: 'freq_sync_py' object has no attribute 'set_min_output_buffer' Is there a possibility to solve this problem or do I have to find an alternative solution, e. g. creating an internal buffer? There is an API call set_output_multiple, this sets the minimum reserve size for buffers. So your worker should only get called with buffers of at least this size. -josh Best regards Felix Wunsch ___ 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] Wideband Software Defined Radio Transceiver coming to a Kickstarter nearest you soon
Hello All, I have been demonstrating what I call creating Google Software Defined Radio GSM Mobile Phone Networks around Chicago and am to present/demonstrate this device tomorrow before the MIT Enterprise Forum of Chicago: www.MITEFChicago.org Zero Daughter Cards are necessary! I'll post more information on: www.WindyCitySDR.com A visual way at looking at the RF Transceiver Capabilibities of this device is viewable here: http://youtu.be/ZEqv9rOMkCI And shall be launching a SDR Kickstarter Campaign from this website: www.Americainc.com I'll include a LiveCD that is configured to work with OpenBTS 2.8 with Gnu Radio possibly. http://forums.hak5.org/index.php?/topic/29213-wideband-software-defined-radio-transceiver/?p=221487 Sincerely. mar...@windycitysdr.com ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Async Messages for Tx Timestamps
Hi, I have a packet-based application where it would be useful to know exactly when each packet has been successfully radiated by the USRP (N200). It seems that UHD and gr-uhd already provide similar functionality for receiving asynchronous messages when a burst has been successfully transmitted (EVENT_CODE_BURST_ACK). However, in my application, I'm transmitting continuously and don't use end_of_burst tags. Would it be possible for the USRP to post messages to the event queue when it has transmitted a sample with a generic tag attached? If not, will I experience an interruption of my signal or any latency if I insert end_of_burst tags into my continuous stream of samples? Your advice is greatly appreciated. Thanks! Jordan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Google Summer of Code: We're in!
Hi everyone! I'm happy to say we've been accepted for GSoC 2013! Our GSoC page is up and running at http://www.google-melange.com/gsoc/org/google/gsoc2013/gnuradio. We'll be adding details soon. Students, how about making some $$$ writing code for the community? Check out our ideas page. Cheerio, MB -- Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin Braun Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-43790 Fax: +49 721 608-46071 www.cel.kit.edu KIT -- University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association pgpks0vHg2ExC.pgp Description: PGP signature ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Google Summer of Code: We're in!
On Mon, Apr 8, 2013 at 11:36 PM, Martin Braun (CEL) martin.br...@kit.edu wrote: Hi everyone! I'm happy to say we've been accepted for GSoC 2013! Our GSoC page is up and running at http://www.google-melange.com/gsoc/org/google/gsoc2013/gnuradio. We'll be adding details soon. Students, how about making some $$$ writing code for the community? Check out our ideas page. That's great new Martin, congratulations! Alex ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Alamouti code
Karen, I have implemented 2x1 alamouti encoding/decoding in openLTE ( http://sourceforge.net/projects/openlte/). Hope this helps, Ben On Apr 8, 2013 5:53 AM, Karan Talasila karan@gmail.com wrote: HI Has there been any implementation of alamouti code on gnuradio for a 2*1 mimo setup. Any ideas or references to get started on it. -- Regards Karan Talasila ___ 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] Tranmit packet number with the payload
Hi, Is it possible to transmit payload with the packet number .So,that we can know which packet is actually dropped. If it is possible please suggest me what all things to be taken care of for it to work. thanks. - Manjusha -- View this message in context: http://gnuradio.4.n7.nabble.com/Tranmit-packet-number-with-the-payload-tp40675.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
Re: [Discuss-gnuradio] Redmine, GNU Radio Wiki and LaTeX
On Sun, Apr 7, 2013 at 3:44 PM, Brian Padalino bpadal...@gmail.com wrote: I tried looking but I couldn't find a way to inline LaTeX equations on the GNU Radio wiki or if there was some plugin required that wasn't installed? Something like mathjax support would be great if we could have it, but I am completely out of my element here. Suggestions? Ideas? Am I just being silly and there's already a way to do it? So apparently there is a plugin for Redmine (what gnuradio.org runs on) that provides mathjax support: https://github.com/holidayworking/redmine_latex_mathjax It's looks straightforward but I have to check version compatibilities, dependencies, etc. -- Johnathan Corgan Corgan Labs - SDR Training and Development Services http://corganlabs.com ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Async Messages for Tx Timestamps
On 04/08/2013 04:45 PM, Jordan Otomo wrote: Hi, I have a packet-based application where it would be useful to know exactly when each packet has been successfully radiated by the USRP (N200). It seems that UHD and gr-uhd already provide similar functionality for receiving asynchronous messages when a burst has been successfully transmitted (EVENT_CODE_BURST_ACK). However, in my application, I'm transmitting continuously and don't use end_of_burst tags. Would it be possible for the USRP to post messages to the event queue when it has transmitted a sample with a generic tag attached? If not, will I experience an interruption of my signal or any latency if I insert end_of_burst tags into my continuous stream of samples? Your advice is greatly appreciated. I'm a bit confused by what you mean when you say you're transmitting continuously in a packet-based application. Are the packets back-to-back in your sample stream? Or are you stuffing a bunch of zero samples in between packets? That isn't the cleanest way to do it. It would be better to use start-of-burst (tx_sob) and end-of-burst (tx_eob) tags if you're using gnuradio. Gnuradio end-of-burst tags will signal UHD firmware to bring down the TX chain. The tag gets converted into a flag in a metadata struct. This struct is sent with an 1-sample buffer of samples when send(...) is called in gr_uhd_usrp_sink. (See line 376 and thereabouts here: http://gnuradio.org/cgit/gnuradio.git/tree/gr-uhd/lib/gr_uhd_usrp_sink.cc). Thanks! Jordan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio Hope this helps! --sean ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Async Messages for Tx Timestamps
Gnuradio end-of-burst tags will signal UHD firmware to bring down the TX chain. The tag gets converted into a flag in a metadata struct. This struct is sent with an 1-sample buffer of samples when send(...) is called in gr_uhd_usrp_sink. (See line 376 and thereabouts here: http://gnuradio.org/cgit/gnuradio.git/tree/gr-uhd/lib/gr_uhd_usrp_sink.cc). A little background here: Jordan has a use case that requires continuous generation of some sort of baseband carrier, which needs to be present with or without actual data to send. The challenge is to continually send data, but to not to the extent that it backs up the pipeline completely full of empty carrier. The transmit DUC in the usrp pulls samples out at a fixed rate, so waiting on the pipeline to drain 100% before getting useful data transmitted can be quite a long wait. 1) The solution is to implement some sort of point-to-point flow control between the source block and the TX DUC in the USRP. Now something like this actually happens to exist which is used internally in UHD to implement transmit flow control. However, it reports consumed sequence numbers of packets, which isnt useful to the source block because its cant translate between items produced and packet counts over the ethernet. 2) Now we could make it work. This one liner could enable the async messages for the usrp2 tx flow control back to the user api. http://pastebin.com/1nsmMUPu And this one liner could enforce fixed length packets, so you could easily relate samples produced to packet sequence numbers consumed: http://pastebin.com/fig7YeSf 3) So aside from that, I was also thinking of another way to do a sort of point to point flow control, but using the rx timestamps as the async reporting. By transmitting samples at a known time, and using a receiver stream and its timestamps to judge when a certain window of samples had been consumed by the DUC chain. 4) Or another way, depending upon the tolerance to variability, one could also forgo the RX timestamps and poll the get_time_now call on the sink block periodically to establish the same concept of time window. Thoughts? -josh Thanks! Jordan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio Hope this helps! --sean ___ 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] Redmine, GNU Radio Wiki and LaTeX
On Mon, Apr 8, 2013 at 6:22 PM, Johnathan Corgan johnat...@corganlabs.com wrote: On Sun, Apr 7, 2013 at 3:44 PM, Brian Padalino bpadal...@gmail.com wrote: I tried looking but I couldn't find a way to inline LaTeX equations on the GNU Radio wiki or if there was some plugin required that wasn't installed? Something like mathjax support would be great if we could have it, but I am completely out of my element here. Suggestions? Ideas? Am I just being silly and there's already a way to do it? So apparently there is a plugin for Redmine (what gnuradio.org runs on) that provides mathjax support: https://github.com/holidayworking/redmine_latex_mathjax It's looks straightforward but I have to check version compatibilities, dependencies, etc. -- Johnathan Corgan Corgan Labs - SDR Training and Development Services http://corganlabs.com Yeah, this would be great to have this ability on the Wiki. Would make the whole idea of discussing signal processing there much more useful. In the meantime you could use something like the following to create a latex-rended equation, make an image out of it, and post that image onto the page: http://www.codecogs.com/latex/eqneditor.php But native support will help a lot with collaboration. Tom ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Google Summer of Code: We're in!
Nice work, Martin. Tom On Mon, Apr 8, 2013 at 5:36 PM, Martin Braun (CEL) martin.br...@kit.edu wrote: Hi everyone! I'm happy to say we've been accepted for GSoC 2013! Our GSoC page is up and running at http://www.google-melange.com/gsoc/org/google/gsoc2013/gnuradio. We'll be adding details soon. Students, how about making some $$$ writing code for the community? Check out our ideas page. Cheerio, 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] Async Messages for Tx Timestamps
Hi Josh and Sean, Thanks for your replies. Sorry for the confusion. As Josh mentioned, my application is packet based, but a carrier signal is sent when packets aren't being transmitted. Josh, I like your second solution. At what point are the control messages generated? Are they generated as the samples are consumed by the DUC? I'm currently using your tx_pacer idea to ensure that the block buffers (gr_vmcircbuf), network buffer, and SRAM never fill completely. This gives me a fairly good idea about when packets are being generated and has greatly reduced transmit latency. However, I'd like to have more precise info about when the USRP is actually radiating the samples. I will try your suggestion and let you know how it works out. Thanks again for your help! Jordan On Apr 8, 2013, at 4:40 PM, Josh Blum wrote: Gnuradio end-of-burst tags will signal UHD firmware to bring down the TX chain. The tag gets converted into a flag in a metadata struct. This struct is sent with an 1-sample buffer of samples when send(...) is called in gr_uhd_usrp_sink. (See line 376 and thereabouts here: http://gnuradio.org/cgit/gnuradio.git/tree/gr-uhd/lib/gr_uhd_usrp_sink.cc). A little background here: Jordan has a use case that requires continuous generation of some sort of baseband carrier, which needs to be present with or without actual data to send. The challenge is to continually send data, but to not to the extent that it backs up the pipeline completely full of empty carrier. The transmit DUC in the usrp pulls samples out at a fixed rate, so waiting on the pipeline to drain 100% before getting useful data transmitted can be quite a long wait. 1) The solution is to implement some sort of point-to-point flow control between the source block and the TX DUC in the USRP. Now something like this actually happens to exist which is used internally in UHD to implement transmit flow control. However, it reports consumed sequence numbers of packets, which isnt useful to the source block because its cant translate between items produced and packet counts over the ethernet. 2) Now we could make it work. This one liner could enable the async messages for the usrp2 tx flow control back to the user api. http://pastebin.com/1nsmMUPu And this one liner could enforce fixed length packets, so you could easily relate samples produced to packet sequence numbers consumed: http://pastebin.com/fig7YeSf 3) So aside from that, I was also thinking of another way to do a sort of point to point flow control, but using the rx timestamps as the async reporting. By transmitting samples at a known time, and using a receiver stream and its timestamps to judge when a certain window of samples had been consumed by the DUC chain. 4) Or another way, depending upon the tolerance to variability, one could also forgo the RX timestamps and poll the get_time_now call on the sink block periodically to establish the same concept of time window. Thoughts? -josh Thanks! Jordan ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio Hope this helps! --sean ___ 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 mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Wideband Software Defined Radio Transceiver coming to a Kickstarter nearest you soon
It would be nice to see some hard technical data, not just only a youtube video. I hate this videomania :) RF specs, sampling rates, DAC/ADC resolution, FPGA/DSP capabilities, stuff like that...just written down as text :) Ralph. From: discuss-gnuradio-bounces+ralph=schmid@gnu.org [mailto:discuss-gnuradio-bounces+ralph=schmid@gnu.org] On Behalf Of Martin O'Shield Sent: Monday, 08 April, 2013 22:13 To: GNURadio Subject: [Discuss-gnuradio] Wideband Software Defined Radio Transceiver coming to a Kickstarter nearest you soon Hello All, I have been demonstrating what I call creating Google Software Defined Radio GSM Mobile Phone Networks around Chicago and am to present/demonstrate this device tomorrow before the MIT Enterprise Forum of Chicago: www.MITEFChicago.org Zero Daughter Cards are necessary! I'll post more information on: www.WindyCitySDR.com A visual way at looking at the RF Transceiver Capabilibities of this device is viewable here: http://youtu.be/ZEqv9rOMkCI And shall be launching a SDR Kickstarter Campaign from this website: www.Americainc.com I'll include a LiveCD that is configured to work with OpenBTS 2.8 with Gnu Radio possibly. http://forums.hak5.org/index.php?/topic/29213-wideband-software-defined-radi o-transceiver/?p=221487 Sincerely. mar...@windycitysdr.com ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
