Competitive with SSB on VHF (AWGN non fading) channels. This mode will be error free when SSB is full of noise. Not a HF solution. But that's coming.
On 18/03/16 07:18, Bruce Perens wrote: > Did I hear that right? Works with non linear amplifiers, competitive > with SSB, replaces all your multi carrier modems? > > > On Thu, Mar 17, 2016, 11:51 David Rowe <da...@rowetel.com > <mailto:da...@rowetel.com>> wrote: > > Hi Adrian, > > Getting the modem right can be really critical. It's good that we are > discovering this and talking about it in Ham and open source circles, > and getting high quality modem code out there. > > I learned about modems in the sat-com industry. As the satellites are > expensive, we would try to get our modems to within 0.25dB of theory. > Otherwise we were just wasting mega-$. > > It still puzzles me why something like DMR has deliberately chosen a > modem waveform (with less than Rs Hz spacing tones) that hobbles the > system by 6dB. The power being wasted is like throwing away 3/4 of your > HT battery. > > Suspect of your 16dB loss is a measurement error or perhaps the FM modem > is not set up right. I found simulating analog FM and getting > performance like the text books to be surprisingly difficult: > > http://www.rowetel.com/blog/?p=3799 > > Maybe you could first test your FM modem, see if you can get the C/No > input versus SNR out curve. > > Looking forward, FreeDV 2400A is competitive with SSB for weak signal > work today, and I think we can push down another 10dB over time. > > Cheers, > > David > > On 17/03/16 23:11, Adrian Musceac wrote: > > Hi Brady, David, > > > > Thank you very much for sharing the GRC flowgraphs. This will help me > > a lot setting up a similar test. Regarding the performance, I was > just > > surprised to see such a big difference between a modem which runs > > through analog FM and your new modem. I would have expected something > > in the range of 6-10 dB, not 16-20 dB. Maybe I need to calibrate my > > signal again. > > I enjoyed a lot reading about the experiment on your blog David. It > > seems like a new revolution for VHF/UHF weak signal work. > > > > 73, > > Adrian (YO8RZZ) > > > > On 3/17/16, Brady O'Brien <brady.obrien...@gmail.com > <mailto:brady.obrien...@gmail.com>> wrote: > >> Hey Adrian, > >> > >> The gnuradio-companion pipelines I used for the test are > attached. These > >> grc pipelines are only meant to get 16-bit 48k samples in and > out of the > >> HackRF and rtlsdr for testing. The meat of the FSK is done with > the C fsk > >> modem, used in freedv_rx, freedv_tx, fsk_mod, and fsk_demod. We > are also > >> running our FSK modem directly from SDR samples instead of > through FM > >> radios. We will be running 2400B over legacy FM radios, but > don't yet have > >> the same degree of test coverage. > >> > >> Thanks, > >> > >> Brady O'Brien > >> > >> On Wed, Mar 16, 2016 at 3:34 PM, Adrian Musceac > <kanto...@gmail.com <mailto:kanto...@gmail.com>> wrote: > >> > >>> Hi David, > >>> > >>> Is it possible to get our hands on the Gnuradio code? I've been > trying > >>> to optimize modems running at 1200 bits/second and the best I > could do > >>> was 100% copy at 8 dB above analog FM for DBPSK and 12 dB above for > >>> GMSK. Your modem seems to be 16-20 dB better than that! If I > could see > >>> the Gnuradio graph maybe I could figure out what I'm doing wrong. > >>> > >>> Thanks, > >>> Adrian > >>> > >>> On 3/16/16, Steve <coupaydevi...@gmail.com > <mailto:coupaydevi...@gmail.com>> wrote: > >>>> Ha, I wish it was through a radio! > >>>> > >>>> I'm trying to think what I have laying around here that might > make a > >>>> good > >>>> transmitter for it. > >>>> > >>>> On Wed, Mar 16, 2016 at 4:02 AM, glen english > <g...@cortexrf.com.au <mailto:g...@cortexrf.com.au>> > >>> wrote: > >>>> > >>>>> ah. good stuff. nice progress. > >>>>> > >>>>> > >>>>> On 16/03/2016 7:50 PM, Steve wrote: > >>>>> > >>>>> Just using the script: > >>>>> > >>>>> freedv_tx 2400A ve9qrp_10s.raw modem.raw > >>>>> > >>>>> Which produces a RAW audio file sampled at 48 kHz and > importing that > >>> into > >>>>> audacity. > >>>>> > >>>>> On Wed, Mar 16, 2016 at 3:46 AM, glen english > <g...@cortexrf.com.au <mailto:g...@cortexrf.com.au>> > >>>>> wrote: > >>>>> > >>>>>> Hi Steve > >>>>>> > >>>>>> Nice > >>>>>> > >>>>>> is that through a PA- if so, linear or linear in say 3dB > compression? > >>>>>> > >>>>>> > >>>>>> On 16/03/2016 7:42 PM, Steve wrote: > >>>>>> > >>>>>> Thought I'd upload a spectrum snapshot. You can't really see the > >>>>>> carriers > >>>>>> until you drop the number of samples to about 256, but this > shows how > >>>>>> wide > >>>>>> it is. > >>>>>> > >>>>>> I noticed that the freedv_tx was outputting +/- 1.0 signals > and a > >>> couple > >>>>>> of clips going on. Maybe need to knock it down to +/- .5 > like the old > >>>>>> FDM > >>>>>> modes. > >>>>>> > >>>>>> FYI > >>>>>> > >>>>>> Steve > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>> > > ------------------------------------------------------------------------------ > >>>>>> Transform Data into Opportunity. > >>>>>> Accelerate data analysis in your applications with > >>>>>> Intel Data Analytics Acceleration Library. > >>>>>> Click to learn > >>>>>> > more.http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > >>>>>> > >>>>>> > >>>>>> > >>>>>> _______________________________________________ > >>>>>> Freetel-codec2 mailing > >>>>>> listFreetel-codec2@lists.sourceforge.nethttps:// > >>> lists.sourceforge.net/lists/listinfo/freetel-codec2 > <http://lists.sourceforge.net/lists/listinfo/freetel-codec2> > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>> > > ------------------------------------------------------------------------------ > >>>>>> Transform Data into Opportunity. > >>>>>> Accelerate data analysis in your applications with > >>>>>> Intel Data Analytics Acceleration Library. > >>>>>> Click to learn more. > >>>>>> http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > >>>>>> _______________________________________________ > >>>>>> Freetel-codec2 mailing list > >>>>>> Freetel-codec2@lists.sourceforge.net > <mailto:Freetel-codec2@lists.sourceforge.net> > >>>>>> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > >>>>>> > >>>>>> > >>>>> > >>>>> > >>>>> > >>> > > ------------------------------------------------------------------------------ > >>>>> Transform Data into Opportunity. > >>>>> Accelerate data analysis in your applications with > >>>>> Intel Data Analytics Acceleration Library. > >>>>> Click to learn > >>>>> > more.http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > >>>>> > >>>>> > >>>>> > >>>>> _______________________________________________ > >>>>> Freetel-codec2 mailing > >>>>> listFreetel-codec2@lists.sourceforge.nethttps:// > >>> lists.sourceforge.net/lists/listinfo/freetel-codec2 > <http://lists.sourceforge.net/lists/listinfo/freetel-codec2> > >>>>> > >>>>> > >>>>> > >>>>> > >>>>> > >>> > > ------------------------------------------------------------------------------ > >>>>> Transform Data into Opportunity. > >>>>> Accelerate data analysis in your applications with > >>>>> Intel Data Analytics Acceleration Library. > >>>>> Click to learn more. > >>>>> http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > >>>>> _______________________________________________ > >>>>> Freetel-codec2 mailing list > >>>>> Freetel-codec2@lists.sourceforge.net > <mailto:Freetel-codec2@lists.sourceforge.net> > >>>>> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > >>>>> > >>>>> > >>>> > >>> > >>> > >>> > > ------------------------------------------------------------------------------ > >>> Transform Data into Opportunity. > >>> Accelerate data analysis in your applications with > >>> Intel Data Analytics Acceleration Library. > >>> Click to learn more. > >>> http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > >>> _______________________________________________ > >>> Freetel-codec2 mailing list > >>> Freetel-codec2@lists.sourceforge.net > <mailto:Freetel-codec2@lists.sourceforge.net> > >>> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > >>> > >> > > > > > > ------------------------------------------------------------------------------ > > Transform Data into Opportunity. > > Accelerate data analysis in your applications with > > Intel Data Analytics Acceleration Library. > > Click to learn more. > > http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > > _______________________________________________ > > Freetel-codec2 mailing list > > Freetel-codec2@lists.sourceforge.net > <mailto:Freetel-codec2@lists.sourceforge.net> > > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > > > > > ------------------------------------------------------------------------------ > Transform Data into Opportunity. > Accelerate data analysis in your applications with > Intel Data Analytics Acceleration Library. > Click to learn more. > http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > _______________________________________________ > Freetel-codec2 mailing list > Freetel-codec2@lists.sourceforge.net > <mailto:Freetel-codec2@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > > > > ------------------------------------------------------------------------------ > Transform Data into Opportunity. > Accelerate data analysis in your applications with > Intel Data Analytics Acceleration Library. > Click to learn more. > http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 > > > > _______________________________________________ > Freetel-codec2 mailing list > Freetel-codec2@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > ------------------------------------------------------------------------------ Transform Data into Opportunity. 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