There should be enough free resources, no need to pay big $$$ for books. Other than what you list, have a look at http://gnuradio.org/redmine/projects/gnuradio/wiki/SuggestedReading.
M On 07/17/2015 06:19 PM, Bill Eaton wrote: >> ... so I recommend you get an intro book to digital comms and map what > they >> say to the GNU Radio examples. > > Yeah. I was afraid it might come to this. Do you have any recommendations? > Most digital comms textbooks are pretty pricey, and I'd hate to spend time > and money on one that might not be a good fit. > > There are free options. There's the MIT course and the Lapidoth PDF book. I > suspect I might prefer a real printed book with nice graphics. > > Thanks in advance, > > Bill Eaton > > > > -----Original Message----- > From: discuss-gnuradio-bounces+billeaton=aeroantenna....@gnu.org > [mailto:discuss-gnuradio-bounces+billeaton=aeroantenna....@gnu.org] On > Behalf Of Martin Braun > Sent: Friday, July 17, 2015 3:04 PM > To: discuss-gnuradio@gnu.org > Subject: Re: [Discuss-gnuradio] trouble with QAM mod/ WX GUI Constellation > Sink > > On 17.07.2015 14:56, Bill Eaton wrote: >>> What I meant was that you plot the result of your timing + phase >>> recovery >> >>> into an XY plot, that would take care of those additional points >> you're seeing. >> >> I have to confess that I don't even know what that means or how to go >> about accomplishing it. I have to take baby steps because I'm a baby. >> ;-) If you could point me to an example or some other things to try, >> that would be helpful. > > OK, this is starting to get into basics of digital comms and this mailing > list is probably not a good place for that. > > In brief, what you're plotting is the output of the QAM Mod -- which is > *not* a QAM constellation, but rather the complex baseband signal that can > be transmitted. This does include the QAM constellation. > >> I looked through the examples that ship with GNURadio and didn't see >> anything obvious. Also, I looked through the GRC block tree to see if >> I could try something. There's a Synchronizers section. Something from > there? > > Try the examples in gr-digital. > >> You thought maybe it was oversampled. It occurred to me that maybe the >> X-Y chart rate should be samp_rate/8, but I tried that and the chart >> still look largely the same. > > That's not quite the right terminology, but if you plotted only a subset of > the samples of your signal, you would see the constellation. > > It seems you're fine using GNU Radio itself, so I recommend you get an intro > book to digital comms and map what the say to the GNU Radio examples. > > Cheers, > Martin > > >> >> >> >> mlist_qam_constellation_xy.grc.png >> >> >> >> >> >> >> >> -----Original Message----- >> From: discuss-gnuradio-bounces+billeaton=aeroantenna....@gnu.org >> [mailto:discuss-gnuradio-bounces+billeaton=aeroantenna....@gnu.org] On >> Behalf Of Martin Braun >> Sent: Friday, July 17, 2015 1:20 PM >> To: discuss-gnuradio@gnu.org >> Subject: Re: [Discuss-gnuradio] trouble with QAM mod/ WX GUI >> Constellation Sink >> >> >> >> On 17.07.2015 12:43, Bill Eaton wrote: >> >>> From Martin Braun: >> >>> >> >>>> My preference is to build the demod/sync chain with it's own blocks, >> >>>> and then just output the complex symbols >> >>> >> >>>> into either an X/Y plot (WX) or the QT Constellation Sink >> >>> >> >>> Even an X/Y plot ends up looking funny. I've attached a GRC file for >> >>> X-Y, and when you turn on persistence, it looks better. But it's very >> >>> strange. Maybe my bits_per_symbol is wrong. Or maybe the sample rate >> >>> for the X-Y chart should be different than the random sample rate? >> >>> Here's the 4 QAM X-Y. >> >> >> >> Your plot looks fine, it's just oversampled (but perfectly >> time-synchronized, I'm guessing this is post-pulse shaping + noise?). >> >> >> >> What I meant was that you plot the result of your timing + phase >> recovery into an XY plot, that would take care of those additional >> points you're seeing. >> >> >> >> M >> >> >> >> >> >> _______________________________________________ >> >> 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 > > > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
