Re: [Discuss-gnuradio] gr-trellis: convenc and viterbi with own mapper/de-mapper
-- Forwarded message -- From: Achilleas Anastasopoulos Date: Thu, Aug 19, 2010 at 4:19 AM Subject: Re: [Discuss-gnuradio] gr-trellis: convenc and viterbi with own mapper/de-mapper To: jonas.boer...@rwth-aachen.de Jonas, there is a very extensive doc file in gr-trellis that hopefully answers your questions, as well as a lot of examples. Please read it and let me know if you still have questions about it. BTW: your issue has nothing to do with truncation as was suggested in a reply. In short: one way to implement your system is to mapp the encoded symbols directly to QPSK symbols (essentially this is what you are doing!) and thus produce 5 demodulated symbols that you will feed in the VA. Achilleas ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Distorted playback of real-time audio on Linux
On Aug 19, 2010, at 1:31 AM, Elvis Dowson wrote: The issue manifests itself on both a VM and with GR running natively on my hardware (late 2009 iMac 27" i7). My US$0.02 worth: TTBOMK&M, on the Mac OS X side you can input and output about any sample rate & CoreAudio will handle the sample rate conversion for you to / from what the hardware requires / provides. If you have audio issues on the native side, those issues are probably not with the audio source or sink. That said, I've also never worked on an i7 & from my reading there are subtle differences in execution between it and the Core2 series. While I doubt the processor is the issue, you never know. Good luck with your continued debugging. - MLD ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Help : Can we capture multiple freq using usrp simultaneously.
Hi everyone , I was just wondering if we can capture multiple frequency from usrp simulataneously.If not why is it so.And if we can , can some one tell me if we need to change the usrp programming part , means fpga programming /c++ programming / or any. Thanks all for your concern in advance. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] sma adapters?
has anyone done a permanent install of a usrp1 or usrp2 with heavy duty feed line? pictures?? how to secure everything? my coax is just lmmr400 with a N Male, i need either a jumper cable or adapter. which has method works best? suggested vendors? thanks ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Octave/MATLAB code for USRP2 DDC ?
On Aug 18, 2010, at 7:42 PM, Johnathan Corgan wrote: > On Fri, Aug 13, 2010 at 12:06, Marc Epard wrote: > >> Does anyone happen to have Octave or MATLAB code that models the USRP2's DDC >> (CIC and HBFs)? > > This covers the CIC portion: > > http://gnuradio.org/redmine/repositories/annotate/gnuradio/gnuradio-core/src/utils/plot_cic_decimator_response.m > > Well lookie there. Already in my home folder. Thanks! -Marc ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC+USRPx file sink problem
Thanks, so it is. Unfortunately though, I have discovered that the gain for an RFX card cannot be adjusted (min=0, max=0, step=0), requiring a massive multiply value in gnuradio-companion, so its all very distorted. :-( Cheers, Dave - Original Message From: Marcus D. Leech To: discuss-gnuradio@gnu.org Sent: Wed, 18 August, 2010 20:26:38 Subject: Re: [Discuss-gnuradio] GRC+USRPx file sink problem On 08/18/2010 01:41 PM, David Evans wrote: > Hi, > > GRC Setup (used with RFX and WBX cards)... > > USRP1 ---to---> FFT Graphical sink (shows signal spectrum as expected) > and ---to---> Complex to IShort -to> File Sink (signals are >dumped > > to disk as expected) > > USRP2 ---to---> FFT Graphical sink (shows signal spectrum as expected) > and ---to---> Complex to IShort to> File Sink (**file is > all > zeros**) > > Tried with 3.3.0 and git 3.3.1, and on three different installations/USRPs. > Basically zero output with USRP2. > USRP2 works fine with python scripts eg, usrp2_fft.py with --output-shorts. > > Any ideas please? > > Dave > > My guess is that with USRP2, samples are scaled -1.0 to 1.0. Which means that a straight conversion to a short integer is going to yield zero most of the time. Try putting a multiplier block in front of your file sink--maybe scale those -1.0 to +1.0 to +/- 32767. -- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] How often is PPS sampled ?
Hi All, How often is PPS sampled? I guess the answer is that the USRP2 runs at 100MHz so it reads that input at the same rate ... or ? BR/ Per ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] GRC+USRPx file sink problem
> > Thanks, so it is. > > Unfortunately though, I have discovered that the gain for an RFX card cannot > be > adjusted (min=0, max=0, step=0), requiring a massive multiply value in > gnuradio-companion, so its all very distorted. :-( > > Cheers, > Dave > It should *not* be distorted just because of a multiply in the signal path, unless that multiplied value is getting clipped when converting to an ISHORT--but that will only be "distorted" downstream from that conversion. Most of the functions that operate on floats in Gnu Radio are perfectly happy with pretty much the entire machine-native range of floats. But certainly when you convert from a floating-point value to an integer value like a short, you have to be aware of conversion losses that can screw you up, so scale appropriately. Cheers -- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] BURX 26MHz clock
Hi, Probably a stupid question... By connecting the BURX's 26MHz clock to the USRP2's 100MHz ref. input, as described in the source, does this pull the mainboard clock to 26MHz, or does it just phase lock to it? i.e. if I collect samples with usrp2_rx_cfile, these will all be samples at 26MHz? Thanks Dave ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] BURX 26MHz clock
On Thu, Aug 19, 2010 at 12:17 PM, David Evans wrote: > Hi, > > Probably a stupid question... > By connecting the BURX's 26MHz clock to the USRP2's 100MHz ref. input, as > described in the source, does this pull the mainboard clock to 26MHz, or does > it > just phase lock to it? i.e. if I collect samples with usrp2_rx_cfile, these > will > all be samples at 26MHz? On the USRP2, there isn't any way to provide an external clock source (at least not a straight-forward way...you can always unsolder the 100 MHz oscillator etc). So if you're interested in using the BURX's on-board 26 MHz TCVCXO, this would clock the BURX board only, leaving the A/D converters still running at 100 Msamples/sec. The USRP2 can phase lock to an external 10 MHz reference, and it is also possible (with firmware modifications to the aeMB code) to phase lock to a reference clock frequency other than 10 MHz (this has been a topic of discussion on the mailing list over the last week or so). So you can access the 26 MHz TCVCXO output of the BURX board through the U.FL connector, and route it to the SMA input on the USRP2 where the 10 MHz reference typically goes, which will phase lock the two clocks. But you will need to tweak the aeMB firware to make this happen. -- John Orlando CEO/System Architect Epiq Solutions www.epiq-solutions.com ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] sma adapters?
On Aug 19, 2010, at 5:15 AM, dave k wrote: > has anyone done a permanent install of a usrp1 or usrp2 with heavy duty feed > line? pictures?? how to secure everything? my coax is just lmmr400 with a N > Male, i need either a jumper cable or adapter. which has method works best? > suggested vendors? thanks A short jumper cable between the thick LMR400 cable and the USRP might be a good idea for strain relief. You can order all of the required adapters and cables from a distributor like Digi-Key, or a cable/adapter vendor like Pasternack. Pasternack will also make custom cables in single quantity. -- Mark J. Blair, NF6X Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] How often is PPS sampled ?
On 08/19/2010 09:47 AM, Per Zetterberg wrote: Hi All, How often is PPS sampled? I guess the answer is that the USRP2 runs at 100MHz so it reads that input at the same rate ... or ? BR/ Per 100 MHz ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] CGRAN now keeps project stats, and OFDMA project added
Hi all, At the request of several users, CGRAN now keeps track of project statistics through SVN logging. This keeps track of checkouts and updates, on a per-project basis. So if anyone wants statistics for the number of "downloads" on their project (starting as of today), you can email me privately. I do *not* log IP addresses, here is a sample log line: [19/Aug/2010:13:28:30 -0400] - checkout-or-export /projects/cmu_macs r507 depth=infinity That's all that is logged when I checkout this project. This way we can keep anonymous per-project statistics and I can email out project log files when needed. Maybe in the future I can integrate a download count on to each project page. But, I doubt trac is dynamically friendly. Check out the new projects below... Thanks! George - NEW PROJECTS - "Development Tools" by Martin Braun - a set of tools, scripts, and other things to help developers on GNU Radio. (I have moved this project to the top of the "projects" list so others can contribute tools to this same project) "Dynamic Spectrum Sharing" by Lei Yang (UCSB) et al. - an OFDMA implementation to evaluate contiguous and non-contiguous spectrum access, detailed in their NSDI 2009 paper (linked on the page). ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] sma adapters?
> > On Aug 19, 2010, at 5:15 AM, dave k wrote: > >> has anyone done a permanent install of a usrp1 or usrp2 with heavy duty feed >> line? pictures?? how to secure everything? my coax is just lmmr400 with a N >> Male, i need either a jumper cable or adapter. which has method works best? >> suggested vendors? thanks >> > A short jumper cable between the thick LMR400 cable and the USRP might be a > good idea for strain relief. You can order all of the required adapters and > cables from a distributor like Digi-Key, or a cable/adapter vendor like > Pasternack. Pasternack will also make custom cables in single quantity. > > > > I'll add Jameco and Mouser to the list of vendors who sell RF adaptors/cables, etc. When I've had to do this, I've put an 'N' to SMA on the fat cable, and used a short piece of thin flexible cable with SMAs on it. Jameco stocks cables with SMAs with both RG58 and RG-174. The RG174 is thin, but lossy, so you don't want to use too much of it, depending on your operating frequency. -- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] sma adapters?
On Aug 19, 2010, at 11:10 AM, Marcus D. Leech wrote: > When I've had to do this, I've put an 'N' to SMA on the fat cable, and > used a short piece of thin flexible cable with SMAs on it. That's exactly what I did in my semi-permanent GPS-disciplined oscillator installation. I also do the same thing when I connect my outdoor discone antenna to my USRP. Both of them have thick feedlines (similar to RG8, LMR400, etc.) terminated with male N connectors, and that's a lot of mass and leverage to hang off a little SMA connector. -- Mark J. Blair, NF6X Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Phase delay direction finding
Hello, I'm trying to implement the calculation of phase delay using a routine of direction finding. I have two daugtherboards lfrx in a USRP at 25MHz and I intend to put the subdevice rxab in order to receive a stream complex in each daugtherboards. In each of daugtherboard will be placed an omnidirectional antenna with band of 20-1300MHz. The question is: is possible to obtain the phase delay making a stream by multiplying the complex conjugate of the other stream and taking the arctan? Thanks Pierry Reinaldo ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Receiver gain setting of XCVR2450 in UHD code
Hi Josh and List, In the data-sheet of the MAX2829 circuit two receiver gains are specified "Receiver Front-End Gain-Control Settings" and "Receiver Baseband VGA Gain Settings". From the UHD API we only have one gain parameter. I have been searching in the UHD code to find where (and how) the split is done, but I can't find it.. BR/ Per ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
