Re: [Discuss-gnuradio] A question on wfm_rcv_gui.py
I still can't figure it out. Can anyone of you guys help me with it? > Hi guys > > I got a bit confused by the code for FM demodulator. > In function parseargs(), why we return freq1 - 128e6 > instead of freq1 itself? What does 128M stand for? > > Thanks > > Sachi > > > > __ > Do you Yahoo!? > Yahoo! Small Business - Try our new resources site! > http://smallbusiness.yahoo.com/resources/ > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > __ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] A question on wfm_rcv_gui.py
Thanks Eric, so the usrp accepts negative IF¡¡frequency? Sachi --- Eric Blossom <[EMAIL PROTECTED]> wrote: > On Sun, Mar 20, 2005 at 04:47:11PM -0800, Sachi > wrote: > > I still can't figure it out. Can anyone of you > guys > > help me with it? > > > > > Hi guys > > > > > > I got a bit confused by the code for FM > demodulator. > > > In function parseargs(), why we return freq1 - > 128e6 > > > instead of freq1 itself? What does 128M stand > for? > > > > > > Thanks > > > > > > Sachi > > Let me take a shot at it. Matt wrote it, but I > think he's off-line > for the weekend. > > wfm_rcv_gui was written assuming that there was no > RF front end doing > any downconversion. > > The A/D sample rate is 64M. > > The Nyquist zones are therefore: > > [0, 32M]normal > [32M, 64M] inverted > [64M, 96M] normal > [96M, 128M] inverted > > etc. > > The problem is that 96M, one of the folding points, > occurs right in > the middle of the broadcast band. > > This means that 95.0 and 97.0 both alias down to the > same frequency > and can't be distinguished from each other. > > freq1 - 128M will give a valid frequency if freq1 is > >= 96M. > > Bottom line: it's a kludge that sort of works. > > Eric > __ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] A question about the synchronization
Hi Eric and Matt When the input IF signal passes quadrature downconverter, does any kind of carrier and symbol synchronization is performed in the FPGA code? If so, which algorithm did you use? Thanks Sachi __ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] wxPython and FC3
I also use FC3, for wxPython, my way is: from the download page: https://sourceforge.net/project/showfiles.php?group_id=10718 download the following rpms wxPython2.5-gtk2-unicode-2.5.4.1-fc2_py2.3.i386.rpm wxPython-common-gtk2-unicode-2.5.4.1-fc2_py2.3.i386.rpm wxPython2.5-devel-gtk2-unicode-2.5.4.1-fc2_py2.3.i386.rpm if you r using python 2.4, you should change them correspondingly. That works Dawei --- [EMAIL PROTECTED] wrote: > What is the best way to get wxPython working under > Fedora Core 3? > > I tried to download and build the source, but it has > been very painful. > > When I run the program I typically get core dumps: > > [EMAIL PROTECTED] usrp]$ ./usrp_fft.py > usrp: found usrp rev2 > RX d'board A: Basic Rx > RX d'board B: Basic Rx > Segmentation fault (core dumped) > [EMAIL PROTECTED] usrp]$ > > [EMAIL PROTECTED] usrp]$ ./wfm_rcv_gui.py 10.7 > usrp: found usrp rev2 > RX d'board A: Basic Rx > RX d'board B: Basic Rx > usrp_standard_rx::set_decim_rate: WARNING rates > > 128 result in incorrect > gain. > >>> gr_fir_fff: using SSE > Segmentation fault (core dumped) > > > On a good note, the O'scope works alright > usrp_oscope.py > > Thanks for any assitance... > > > The following was my last build attempt: > > tar zxf wxPython-src-2.5.4.1.tar.gz > cd wxPython-src-2.5.4.1 > mkdir bld > cd bld > ../configure --prefix=$HOME/gr \ > --enable-rpath=$HOME/gr \ > --with-gtk \ > --with-opengl \ > --enable-debug \ > --enable-geometry \ > --enable-sound --with-sdl \ > --enable-display \ > --disable-debugreport \ > --with-libjpeg=builtin \ > --with-libpng=builtin \ > --with-libtiff=builtin \ > --with-zlib=builtin > > make > make -C contrib/src/gizmos > make -C contrib/src/stc > > make install > make install -C contrib/src/gizmos > make install -C contrib/src/stc > > cd ../wxPython > python setup.py build > python setup.py install --prefix=$HOME/gr > cd > > > > I'm using the following support packages: > > tar zxf fftw-3.0.1.tar.gz > tar xzf swig-1.3.24.tar.gz > tar xzf cppunit-1.10.2.tar.gz > tar xzf sdcc-2.4.0.tar.gz > tar zxf xerces-c-src_2_6_0.tar.gz > > > The of the GNU radio core compiles and runs without > any problems. > > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > __ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] About the am_rcv.py
Hey, guys I am studying the examples these days. I met a question when I read am_rcv.py. Why do we need a offset frequency of 30kHz in this case? src.set_rx_freq (0, IF_freq) actual_IF_freq =src.rx_freq(0) actual_offset = actual_IF_freq + station The three lines are confusing to me, why we need to do so? Thanks very much for your time. Sachi __ Do you Yahoo!? Yahoo! Mail - You care about security. So do we. http://promotions.yahoo.com/new_mail ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] best distro to use GR?
I am using Fedora 3, i586. When you install Fedora 3, make sure you have selected development tools and x-windows development tools. Then I belive your life can be much easier. Sachi --- "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote: > Hi, > > what is the best, or the most used linux flavor to > compile > and use with gnuradio? > > Now I'm using FC3 x86_64, and I have some troubles > with > swig. I have the core compiled but I can not run the > examples. > > I'm only want to use my time to play with gnuradio > and > develope some ideas and tests. I don't want to lost > more > time compiling, and upgrading, and compiling another > time. > > Thanks a lot > > Iban > > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > __ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Segmentation fault
Hi, guys I updated my GNU radio to the 2.5 version. But I met the following "segmentation fault" error when I tried to run wfm_rcv_gui.py usrp_standard_rx::set_decim_rate: WARNING rates > 128 result in incorrect gain. >>> gr_fir_fff: using SSE Segmentation fault Can anyone provide some suggestions on this? BTW: I can pass all tests when I run make check. Thanks Sachi __ Yahoo! Messenger Show us what our next emoticon should look like. Join the fun. http://www.advision.webevents.yahoo.com/emoticontest ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Segmentation fault
By the way, If I run nbfm_rcv.py, I got the same error. But if I use --no-gui option, then the error won't appear. It seems that this error is related tothe graphical use, could any one of you give me any suggestions? Sachi --- Sachi <[EMAIL PROTECTED]> wrote: > Hi, guys > > I updated my GNU radio to the 2.5 version. But I met > the following "segmentation fault" error when I > tried > to run wfm_rcv_gui.py > > usrp_standard_rx::set_decim_rate: WARNING rates > > 128 > result in incorrect gain. > >>> gr_fir_fff: using SSE > Segmentation fault > > Can anyone provide some suggestions on this? BTW: I > can pass all tests when I run make check. > > Thanks > > Sachi > > > > __ > Yahoo! Messenger > Show us what our next emoticon should look like. > Join the fun. > http://www.advision.webevents.yahoo.com/emoticontest > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > __ Yahoo! Messenger Show us what our next emoticon should look like. Join the fun. http://www.advision.webevents.yahoo.com/emoticontest ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Segmentation fault
Yeh, I am using Fedora 3 now. Have you considered how to solve this problem? Sachi --- Raphael Cobo <[EMAIL PROTECTED]> wrote: > Hello, > > I think this is a bug in the underlying libraries > for the GUI in a > specific distribution. > I think that people that use Fedora will experience > the same > bug. Am I right? Can somebody confirm that the SSE > segmentation fault only > happens in Fedora or Redhat? > > > > On Sat, 2 Apr 2005, Sachi wrote: > > > By the way, > > If I run nbfm_rcv.py, I got the same error. But if > I > > use --no-gui option, then the error won't appear. > It > > seems that this error is related tothe graphical > use, > > could any one of you give me any suggestions? > > > > Sachi > > > > --- Sachi <[EMAIL PROTECTED]> wrote: > > > Hi, guys > > > > > > I updated my GNU radio to the 2.5 version. But I > met > > > the following "segmentation fault" error when I > > > tried > > > to run wfm_rcv_gui.py > > > > > > usrp_standard_rx::set_decim_rate: WARNING rates > > > > > 128 > > > result in incorrect gain. > > > >>> gr_fir_fff: using SSE > > > Segmentation fault > > > > > > Can anyone provide some suggestions on this? > BTW: I > > > can pass all tests when I run make check. > > > > > > Thanks > > > > > > Sachi > > > > > > > > > > > > __ > > > Yahoo! Messenger > > > Show us what our next emoticon should look like. > > > Join the fun. > > > > http://www.advision.webevents.yahoo.com/emoticontest > > > > > > > > > ___ > > > Discuss-gnuradio mailing list > > > Discuss-gnuradio@gnu.org > > > > > > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > > > > > > > > __ > > Yahoo! Messenger > > Show us what our next emoticon should look like. > Join the fun. > > > http://www.advision.webevents.yahoo.com/emoticontest > > > > > > ___ > > Discuss-gnuradio mailing list > > Discuss-gnuradio@gnu.org > > > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > __ Do you Yahoo!? Yahoo! Personals - Better first dates. More second dates. http://personals.yahoo.com ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Segmentation fault
Eric May I ask what distribution of Linux you are using and testing GNU Radio now? Sachi --- Raphael Cobo <[EMAIL PROTECTED]> wrote: > > Hello, > > > That's just the last message printed before it seg > faulted. > > That's true. However, it looks like only people > running FC3 have such a > problem, while other distributions don't experience > the same problem. > This is the assumption I was trying to confirm. Is > there a case where > somebody can run the scope example ok using FC3? > > I am also running FC3. I looked into this problem > before am my program > died here: > > >-> return _gnuradio_swig_python.fft_vfc(*args) > >(Pdb) p args > >(512, True, True) > >(Pdb) s > >Segmentation fault > > I believe this breaks in the lib > _gnuradio_swig_python.so located in > /usr/local/lib/python2.3/site-packages/gnuradio/gr > > > Rafael > > > On Sat, 2 Apr 2005, Eric Blossom wrote: > > > On Sat, Apr 02, 2005 at 01:21:53PM -0500, Raphael > Cobo wrote: > > > Hello, > > > > > > I think this is a bug in the underlying > libraries for the GUI in a > > > specific distribution. > > > I think that people that use Fedora will > experience the same > > > bug. Am I right? Can somebody confirm that the > SSE segmentation fault only > > > happens in Fedora or Redhat? > > > > FYI, It's highly unlikely that this has anything > to do with SSE. > > That's just the last message printed before it seg > faulted. > > > > Again, a quick look with gdb will provide real > data... > > > > In the stab-in-the-dark department, do the > wxPython demos run OK on > > your system? Not our demos, the ones that you can > download from wxpython.org. > > > > Eric > > > > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > __ Yahoo! Messenger Show us what our next emoticon should look like. Join the fun. http://www.advision.webevents.yahoo.com/emoticontest ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Segmentation fault
Hi, Eric I have checked it with gdb, it returned: (gdb) continue Continuing. Program received signal SIGSEGV, Segmentation fault. [Switching to Thread -1208514880 (LWP 1030)] 0x007eb73f in m2fv_64_0 () from /usr/local/lib/libfftw3f.so.3 Then gdb stopped. I didn't use any breakpoints in the code. BTW: I can run the demos provided by wxPython. Can you sqeeze any information from this? Or what should I do next? Thanks for your time Sachi --- Eric Blossom <[EMAIL PROTECTED]> wrote: > On Sat, Apr 02, 2005 at 01:21:53PM -0500, Raphael > Cobo wrote: > > Hello, > > > > I think this is a bug in the underlying libraries > for the GUI in a > > specific distribution. > > I think that people that use Fedora will > experience the same > > bug. Am I right? Can somebody confirm that the SSE > segmentation fault only > > happens in Fedora or Redhat? > > FYI, It's highly unlikely that this has anything to > do with SSE. > That's just the last message printed before it seg > faulted. > > Again, a quick look with gdb will provide real > data... > > In the stab-in-the-dark department, do the wxPython > demos run OK on > your system? Not our demos, the ones that you can > download from wxpython.org. > > Eric > __ Do you Yahoo!? Yahoo! Personals - Better first dates. More second dates. http://personals.yahoo.com ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Segmentation fault
Hi, Eric Toby's suggestion helped me solve the problem. If I configure "without" the --enable-sse option, then everything works well. Is --enable-sse option necessary here? Thanks to you guys Sachi --- Eric Blossom <[EMAIL PROTECTED]> wrote: > On Sat, Apr 02, 2005 at 11:03:48PM -0800, Sachi > wrote: > > Hi, Eric > > > > I have checked it with gdb, it returned: > > > > (gdb) continue > > Continuing. > > > > Program received signal SIGSEGV, Segmentation > fault. > > [Switching to Thread -1208514880 (LWP 1030)] > > 0x007eb73f in m2fv_64_0 () from > > /usr/local/lib/libfftw3f.so.3 > > > > Then gdb stopped. I didn't use any breakpoints in > the > > code. BTW: I can run the demos provided by > wxPython. > > > > Can you sqeeze any information from this? Or what > > should I do next? > > Thanks for your time > > Sachi > > This is good info. It's blowing up libfftw3f, the > FFTW code. > Haven't ever seen that failure. > > I'd suggest building fftw from source (www.fftw.org) > using the > --enable-single --enable-sse --enable-shared > configure options, and > then after it's built make sure that its "make > check" passes. > > If this fixes the problem, there may be a problem > with the libfftw3f > library distributed with FC3. > > Eric > __ Yahoo! Messenger Show us what our next emoticon should look like. Join the fun. http://www.advision.webevents.yahoo.com/emoticontest ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Questions on the usrp_fft and usrp_oscope
Hi, guys I met some confusions when I tried the usrp_fft and usrp_oscope. I generate a 2MHz, peak to peak 1V, sin wave using the Agilent signal generator, and connect it to usrp. However, the result of usrp_fft always shows a very strong component at DC, besides the 2MHz. Why is that? Then I tried usrp_oscope, it works pretty well. But when I zoom in, I found the wave form doesn't seem to be sine, but something like square or triangle. Do I miss any parameters here? Thanks so much Sachi __ Do you Yahoo!? Yahoo! Personals - Better first dates. More second dates. http://personals.yahoo.com ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Difference between nbfm_rcv.py and wfm_rcv_gui.py
Hey Guys, What's the main difference between nbfm_rcv.py and wfm_rcv_gui.py? I try to use nbfm_rcv.py to receive FM signals, but the effects are very bad. Do we have any examples demodulating the stereo FM? Thank you for your time BTW: Matt, when will your new daughter boards become available and stable? We are eager to purchase some. Sachi __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] How to receive FM with a TVRX
Hi Matt When will your new daughter boards be available to purchase? Sachi --- Matt Ettus <[EMAIL PROTECTED]> wrote: > > > > > If you have a TVRX board, do not run wfm_rcv_gui.py, > as it will not do what you > want. You need to run tvrx_wfm_rcv_gui.py > > Also, in tvrx_wfm_rcv_gui there is a line that reads > "which_side = 0". This > means that the program is expecting to find your > tvrx board on the "A" side. > If you have yours on the "B" side, change the line > to read "which_side = 1". > > Matt > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > __ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] IP network using GnuRadio
This is so great! --- Meenal <[EMAIL PROTECTED]> wrote: > Hello all, > We have successfully deployed a GnuRadio based IP > network using a TAP/TUN > interface between two machines connected with a loop > back cable. GnuRadio > is used as the physical layer. We use a slotted > ALOHA based MAC layer, > which has been developed here at NCSA. > As a first pass we were able to transmit and receive > UDP data across the > network. The source code and details will be > available on our website > http://www.ncassr.org/projects/sdr/ soon for anyone > interested. I will > email a notification to the group when it becomes > available. > > Regards, > Meenal > > > > Meenal Pant > National Center for Supercomputing Applications, > 405 North Mathews Avenue , > Urbana , > Illinois 61801 > > Ph: 217-244-7318 > Fax: 217-244-2909 > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > Yahoo! Mail Stay connected, organized, and protected. Take the tour: http://tour.mail.yahoo.com/mailtour.html ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Digital Communication using GNU Radio.
Hi all friends I plan to use GNU Radio to develop some digital modulation and demodulation schemes. Could anyone of you guys tell me what kinds of digital modulation and demodulation schemes have been implemented in our group and where I can find the code? I've noticed there is fsk transmission and receiving codes in the example folder. But my experiments don't go well. I simply use an amplifier as the front end (no frequency trans) and I sent a file via the Tx and try to receive the signal using another laptop with usrp board. But I can receive nothing but some weired characters. Can anyone of you help me with it? What's the correct way to run this FSK code? Thanks so much in advance Sachi __ Discover Yahoo! Use Yahoo! to plan a weekend, have fun online and more. Check it out! http://discover.yahoo.com/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Digital Communication using GNU Radio.
Hi, all I am still studying the codes of the FSK_R(T)X.py. It's a little bit confusing because the comments are rather limited. Which algorithm or book chapter does the author refer to when he wrote the codes, especially for the time synchronization part? I think that information can help me understand the code line by line much better. Thanks in advance Sachi --- Sachi <[EMAIL PROTECTED]> wrote: > Hi all friends > > I plan to use GNU Radio to develop some digital > modulation and demodulation schemes. Could anyone of > you guys tell me what kinds of digital modulation > and > demodulation schemes have been implemented in our > group and where I can find the code? > > I've noticed there is fsk transmission and receiving > codes in the example folder. But my experiments > don't > go well. I simply use an amplifier as the front end > (no frequency trans) and I sent a file via the Tx > and > try to receive the signal using another laptop with > usrp board. But I can receive nothing but some > weired > characters. Can anyone of you help me with it? > What's > the correct way to run this FSK code? > > Thanks so much in advance > > Sachi > > > > __ > Discover Yahoo! > Use Yahoo! to plan a weekend, have fun online and > more. Check it out! > http://discover.yahoo.com/ > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > __ Yahoo! Mail Mobile Take Yahoo! Mail with you! Check email on your mobile phone. http://mobile.yahoo.com/learn/mail ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Digital Communication using GNU Radio.
Hi, Eric Thanks very much for your information. It really helps me a lot. But I still have a couple of questions: 1. Does this synchronization algorithm have any specific name? 2. I notice that at the TX side, a payload file need to be sent. So what kind of file should I use here? Any file? Does it have any special format? On the other hand, at the RX side, what should be observed to convince me that the file has been received correctly? Receiving a same file? If possible, could you please give me more information about the how to run the experiments (the command, arguments) 3. I directly use 29.xMHz for transmission and reception (without freq. tuner) with two USRP boards at two PCs, because I think the DAC and ADC can work well for this frequency. I just use two amplifiers at both ends to increase the SNR. So do you think this scenario could work well? Thanks very much for your time Regards SachiEric Blossom <[EMAIL PROTECTED]> wrote: On Thu, Jun 02, 2005 at 09:21:59AM -0700, Sachi wrote:> Hi, all> I am still studying the codes of the FSK_R(T)X.py.> It's a little bit confusing because the comments are> rather limited. > Which algorithm or book chapter does the author refer> to when he wrote the codes, especially for the time> synchronization part? I think that information can> help me understand the code line by line much better.> > Thanks in advance> > Sachi Hi Sachi,The time synchronization method is a standard open loop technique thatworks fine for many uses. It results in establishing both bit timingand frame alignment. Fundamentally we start with a signal that isoversampled 8 times, and then look for a particular synchronizationpattern at every possible offset. When we find the best one, wedeclare that we are synchronized, and use that alignment for theduration of the current frame. It's similar to the oversamplingtechinque used in UARTs to find the middle of the start bit.Synchronization is generally not well covered in intro comms texts.Frerking, "Digital Signal Processing in Communication Systems" is fullof practical digital comms techniques, including some having to dowith synchronization.Meyr, Moeneclaey and Fechtel, "Digital Communications Receivers:Synchronization, Channel Estimation, and Signal Processing" is prettymuch all about synchronization, but is pretty heavy going.Eric Yahoo! Mail Mobile Take Yahoo! Mail with you! Check email on your mobile phone.___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Digital Communication using GNU Radio.
Hi Eric and other friends Today I tried a lot on the FSK TX/RX, by connecting the BasicTX and BasicRX on the same USRP board via a sma-sma cable. I am wondering, what is a good and correct reception? Ideally, I thought it should be, if I send a file, it should be received exactly the same as the original one. However, this is not the case in my experiments. Sometimes, even I didn't send anything, the receiver can still "receive" something and write them into the file. Sometimes, although it is synchronized at the receiver, (the seq no. is correct, going increasingly), the receiving file is still much different with the original one, (might be larger). So what happens? Is there anything wrong with my setting? What can be done for a reliable transmission? Thanks for all your help Sachi --- Sachi <[EMAIL PROTECTED]> wrote: > Hi, Eric > > Thanks very much for your information. It really > helps me a lot. But I still have a couple of > questions: > 1. Does this synchronization algorithm have any > specific name? > 2. I notice that at the TX side, a payload file need > to be sent. So what kind of file should I use here? > Any file? Does it have any special format? On the > other hand, at the RX side, what should be observed > to convince me that the file has been received > correctly? Receiving a same file? If possible, could > you please give me more information about the how to > run the experiments (the command, arguments) > 3. I directly use 29.xMHz for transmission and > reception (without freq. tuner) with two USRP boards > at two PCs, because I think the DAC and ADC can work > well for this frequency. I just use two amplifiers > at both ends to increase the SNR. So do you think > this scenario could work well? > > Thanks very much for your time > > Regards > > Sachi > > Eric Blossom <[EMAIL PROTECTED]> wrote: > On Thu, Jun 02, 2005 at 09:21:59AM -0700, Sachi > wrote: > > Hi, all > > I am still studying the codes of the FSK_R(T)X.py. > > It's a little bit confusing because the comments > are > > rather limited. > > Which algorithm or book chapter does the author > refer > > to when he wrote the codes, especially for the > time > > synchronization part? I think that information can > > help me understand the code line by line much > better. > > > > Thanks in advance > > > > Sachi > > Hi Sachi, > > The time synchronization method is a standard open > loop technique that > works fine for many uses. It results in establishing > both bit timing > and frame alignment. Fundamentally we start with a > signal that is > oversampled 8 times, and then look for a particular > synchronization > pattern at every possible offset. When we find the > best one, we > declare that we are synchronized, and use that > alignment for the > duration of the current frame. It's similar to the > oversampling > techinque used in UARTs to find the middle of the > start bit. > > Synchronization is generally not well covered in > intro comms texts. > > Frerking, "Digital Signal Processing in > Communication Systems" is full > of practical digital comms techniques, including > some having to do > with synchronization. > > Meyr, Moeneclaey and Fechtel, "Digital > Communications Receivers: > Synchronization, Channel Estimation, and Signal > Processing" is pretty > much all about synchronization, but is pretty heavy > going. > > Eric > > > > > - > Yahoo! Mail Mobile > Take Yahoo! Mail with you! Check email on your > mobile phone.> ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > __ Discover Yahoo! Stay in touch with email, IM, photo sharing and more. Check it out! http://discover.yahoo.com/stayintouch.html ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] FIR filter in fsk_tx.py
Hi, Eric I've got a question on the interpolation FIR filter in the fsk_tx.py. Here is the filter uesd: interp_taps = gr.firdes.low_pass (self.sw_interp, # gain self.fs, # sampling rate data_rate / 2 * 1.2, # cutoff data_rate/2 * 0.4, # trans width gr.firdes.WIN_HANN) I am a little confused. Why do you use sw_interp as the gain? And how do you select the cutoff freq. and transition bandwidth? Thanks in advance Sachi Yahoo! Sports Rekindle the Rivalries. Sign up for Fantasy Football http://football.fantasysports.yahoo.com ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] WX version 2.6
Hi, Matt I tried, in Fedora 3. But I failed. So I downgrade it to 2.5.x.x. Sachi --- Matt Ettus <[EMAIL PROTECTED]> wrote: > > > Has anyone here tried using GNU Radio with wx and > wxpython version 2.6? >Were you successful? > > Thanks, > Matt > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > __ Do you Yahoo!? Yahoo! Mail - Find what you need with new enhanced search. http://info.mail.yahoo.com/mail_250 ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] FIR filter in fsk_tx.py
Let me make my question more clear. If I understand the code correctly, after "bytes_to_syms", the signal should be a float sequence of +1 or -1. I am very confused about what the signal will look like after "interp". I think it's no longer +-1 sequence any more. So does it have any special function here? Here are several problems invloved. For the FIR interpolation filter, why we choose 1.2*data_rate/2 as the cutoff frequency and 0.4*data_rate/2 as the transition band? Second, why k = 2 * math.pi * max_deviation / self.fs? Hope anyone of you could help me get out of the confusion. Thanks for your time Sachi --- Sachi <[EMAIL PROTECTED]> wrote: > Hi, Eric > > I've got a question on the interpolation FIR filter > in > the fsk_tx.py. Here is the filter uesd: > > interp_taps = gr.firdes.low_pass (self.sw_interp, > > # gain > > self.fs, # sampling rate > > data_rate / 2 * 1.2, # cutoff > > data_rate/2 * 0.4, # trans width > > gr.firdes.WIN_HANN) > > I am a little confused. Why do you use sw_interp as > the gain? And how do you select the cutoff freq. and > transition bandwidth? > > Thanks in advance > > Sachi > > > > > > Yahoo! Sports > Rekindle the Rivalries. Sign up for Fantasy Football > > http://football.fantasysports.yahoo.com > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > Yahoo! Sports Rekindle the Rivalries. Sign up for Fantasy Football http://football.fantasysports.yahoo.com ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] FIR filter in fsk_tx.py
Hi, Matt Thanks so much, your reply is so helpful. Now I think I can understand the FSK code well. However, I still have some confusions. Hope you or Eric could help me solve them. 1. In gr_simple_correlator.cc, you calculate the hamming distance, using hamming_dist = gr_count_bits32 (d_shift_reg[d_osi] ^ GRSF_SYNC); Why you choose the threshold as 3? Do you choose it from your experiments? If I understand correctly, there should be several "osi" when the hamming distance is less than 3 and we pick up the center one. 2. In fsk_rx.py, you use: u.set_rx_freq (0, -options.cordic_freq) Why a negative IF frequency is used here? What happens if I use the positive one? 3. In fsk_tx.py, the +1, -1 sequence is interpolated by 8 and then processed using a lowpass filter. Why do we have to do this in software? Can we directly send the +1 -1 sequence to the FM modulator? What's the difference? Does it have anything to do with the receiving side? If so, why we have to interpolate it using FIR lowpass filter? Can we duplicate each +1 or -1 8 times? i.e. 1 -1 1 1 -1 becomes -1-1-1-1-1-1-1--1-1-1-1-1-1-1-1 Thank you very much for your time. Sachi __ Yahoo! Mail for Mobile Take Yahoo! Mail with you! Check email on your mobile phone. http://mobile.yahoo.com/learn/mail ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] FIR filter in fsk_tx.py
Hi, Matt, Thanks a lot, now I am able to understand the FSK code completely. Now the only remaining problem is the program doesn't run as it should. Quite often, the receiver can detect something while actually nothing is there, as a result, it receives some messy data into the file. For example, if I only run the receiving program fsk_rx.py, without running the fsk_tx.py, the receiver can still get some data and write it into the file. The ideal situation appearing in my mind is we send a text file, and we should be able to recover it correctly at the receiver and read it. Have you ever really achieved this? Do you have any suggestion that we can improve the realibility of the FSK transmisstion? such as increase the length of the synchronization bits? or decrease the hamming distance? Thanks Sachi --- Matt Ettus <[EMAIL PROTECTED]> wrote: > Sachi wrote: > > Hi, Matt > > > > Thanks so much, your reply is so helpful. Now I > think > > I can understand the FSK code well. However, I > still > > have some confusions. Hope you or Eric could help > me > > solve them. > > > > 1. In gr_simple_correlator.cc, you calculate the > > hamming distance, using > > hamming_dist = gr_count_bits32 (d_shift_reg[d_osi] > ^ > > GRSF_SYNC); > > Why you choose the threshold as 3? Do you choose > it > > from your experiments? If I understand correctly, > > there should be several "osi" when the hamming > > distance is less than 3 and we pick up the center > one. > > > I'm not sure what "osi" is. The threshold is a > compromise between false > positives (i.e. we correlate when nothing is > actually there), and false > negatives (i.e. we miss real packets). 3 was chosen > somewhat arbitrarily. > > > 2. In fsk_rx.py, you use: > > u.set_rx_freq (0, -options.cordic_freq) > > Why a negative IF frequency is used here? What > happens > > if I use the positive one? > > Negative means translate the frequencies lower. So > a signal centered at > cordic_freq and then translated by -cordic_freq ends > up at DC. If you > had used +cordic_freq, you would have translated > whatever is at > -cordic_freq to DC. If you are using a dboard with > real sampling, then > this would be a frequency-inverted version of your > signal, and ones > would be swapped for zeros and vice versa. If you > were using a dboard > with IQ sampling, then your image would be there. > You would see a much > weaker spectrum reversed version of your own signal, > plus any > interferers at your image frequency. > > > 3. In fsk_tx.py, the +1, -1 sequence is > interpolated > > by 8 and then processed using a lowpass filter. > Why do > > we have to do this in software? Can we directly > send > > the +1 -1 sequence to the FM modulator? What's the > > difference? > > The lowpass filter gives a cleaner signal, which > otherwise would extend > very wide. > > > Does it have anything to do with the > > receiving side? If so, why we have to interpolate > it > > using FIR lowpass filter? Can we duplicate each +1 > or > > -1 8 times? i.e. > > 1 -1 1 1 -1 becomes > > > -1-1-1-1-1-1-1--1-1-1-1-1-1-1-1 > > You could do that. That would be the equivalent of > filtering with a > boxcar or sinc filter. It would give relatively > poor filtering of out > of band interference (about -18dB), but better than > nothing. > > Matt > Sell on Yahoo! Auctions no fees. Bid on great items. http://auctions.yahoo.com/ ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] what's going on in gr_float_to_complex?
Hi, guys I've generated a BPSK signal (float), and want to send it by the USRP. But the USRP sink only has two types: _c and _i. So is gr_float_to_complex the correct block I should use before sending the signal to the USRP sink? Thanks Sachi Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] When we combine several streams
Hi, Matt and Eric I have a basic problem regarding the flow schedueling in GNU Radio, especially when we try to combine several sub-streams using a multiplier or an adder. Can we make sure the indexes are still aligned? For example, suppose I want to implement: z[n] = x[n] + c * y[n] Source block A is used to genereate x[1], x[2], x[3]... source block B is used to genereate y[1], y[2], y[3]... Block C, gr_multiply_const_cc, is used to multiply y[n], as the constant c. Block D, gr_add_cc, is used to add the two streams, the flow graph looks like: A->D B->C->D So my question is, can the scheduling mechanism in GNU Radio guarantee the index alignment? I mean, will the block C introduce any delay, or the two sourced generating data in different speeds, so that at the adder D, the index for the two sequence is not aligned any more, but something looks like: z[n] = x[n] + c * y[n - 1]?? Another more complicated example is the FM stereo receiver, after fm-demodulating the input signal, we need to split the data stream into two, process the two sub-streams separately (filtering), and recombine them using an adder and a substractor. Something like: A->B->C->F A->D->E->F I am concerned about whether the index is still aligned at F. Can we make sure (BC) and (DE) introduce the same delay? Thank you very much, the answer to this is very important to me, because I am going implement some complex algorithms. I know the simulink in Matlab could guarantee this, but I am not sure whether GNU Radio could gurantee this, especially when we split up stream and recombine again. Thanks Sachi __ Yahoo! Mail Stay connected, organized, and protected. Take the tour: http://tour.mail.yahoo.com/mailtour.html ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] An error message
Hi all I've got an error message related to the gui: Traceback (most recent call last): File "/usr/local/lib/python2.3/site-packages/gnuradio/wxgui/scopesink.py", line 408, in format_data self.Draw (graphics, xAxis=x_range, yAxis=self.y_range) File "/usr/local/lib/python2.3/site-packages/gnuradio/wxgui/plot.py", line 880, in Draw graphics.scaleAndShift(scale, shift) File "/usr/local/lib/python2.3/site-packages/gnuradio/wxgui/plot.py", line 356, in scaleAndShift o.scaleAndShift(scale, shift) File "/usr/local/lib/python2.3/site-packages/gnuradio/wxgui/plot.py", line 149, in scaleAndShift self.scaled = scale*self.points+shift OverflowError: math range error Has anyone met this before? Although the message appears, the program still runs well as expected. Sachi Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] AGC using RXPGA on MxFE
Hi, Eric Would you please iterate more on the concept of PGA? I don't understand it quite well. Is it just an amplifier after the ADC, so that the 16-bit signed integer is multiplied by the value of pga? Or, let's say the pga is 10, is it true that the p-p value of the adc is not 1V--1V, but 0.1V - -0.1V, so that the ADC can quantize the signal more subtly?? And how about the Tx path? Thanks Sachi --- Eric Blossom <[EMAIL PROTECTED]> wrote: > On Tue, Jul 19, 2005 at 06:08:27AM +0500, Ahmad > Sheikh wrote: > > > The USRP user guide states that there is 20 db of > gain on the > > USRP. Assuming that this is on the Receive path > Programmable Gain > > Amplifier on the MxFE, can this be used as an AGC? > > Yes. > > > I want to control the strength of the signal > received. The way to do > > this, I think, would be to dynamically alter the > value written to > > the Rx A/Rx B registers, using some feedback > control > > mechanism. Would this control be on the FPGA, or > GNU Radio > > Python/C++ software using > usrp.source_c().set_pga()? Is there > > already some structure provided to do this? > > The easiest way is using usrp.source_c().set_pga() > > Eric > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] confusion about set_rx_freq()
Hi, Matt and Eric Today when I looked at the wfm_rcv_gui.py code again, I suddenly got confused by the IF frequency we used. Suppose the FM station we are interested in is centered at 100MHz, then for the 64MHz ADC, it should be mapped to 100-128 = -28MHz, right? My confusion is here: src.set_rx_freq (0, IF_freq). If I remember correctly, Matt has told me that when we use a negative frequency here, we actually move the positive IF band "Down" to baseband. So my understanding is, if we use -28MHz here, we move something around 28MHz, downto baseband. But what we should do is to use set_rx_freq(0,28MHz) to move the band around -28MHz, "Up" to baseband. Otherwise, we invert everything. Could you please help resolve my confusion? Or do I make any mistakes here? Thanks Sachi Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] Still confused about the IF frequency
Hi, Eric and Matt I still can't understand the question I asked in July 26th's email. Hope you could take a look at the email titled "confusion about set_rx_freq()". My understanding is, if we get a "reversed version" of the spectrum, we eventually get the "conjugate version" of the signal in time domain, that is, I channel remains the same, Q channel is reversed. So in "gr_quadrature_demod_cf", when we use "arg(in[i] * conj (in[i-1]))" to approximate the frequency, we shouldn't get the same thing. Do I make any mistakes here? However, in Matt's email on Feb, 16th, Matt said, " 1 - 0.765625 = .234375 .234375 * 64 MHz = 15 MHz Since we had to do that "reflection", the spectrum is reversed. This isn't a problem for FM, but needs to be taken into account for most modulations. Matt " I wonder why it's not a problem for FM?? Thank you very much, looking forward to your reply Sachi Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Still confused about the IF frequency
Hi, Rick Would you please iterate more about why it's not a problem for analog signal? Maybe some mathematics would be very helpful to me. My understanding is if the spectrum is reversed, the signal shouldn't be the same. Thanks Sachi --- Rick Parrish <[EMAIL PROTECTED]> wrote: > Sachi wrote: > > >Since we had to do that "reflection", the spectrum > is reversed. This isn't a problem for FM, but needs > to be taken into account for most modulations. > > > > > For analog audio, no it's not a problem but for > other modes - like FSK > or PSK modulated data, it would (unless I've > completely misunderstood) > invert the signal and therefore the data (but not > for FFSK or other NRZ > modes). > > -rick > > Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
