Hi Ross, While a spreadsheet is easier to work with, I find that Gnuradio is more flexible often. Out of many modes I have tried, I found that the most simple and robust for a 300 - 3000 Hz bandwidth is a 2kbit/s GMSK waveform. There are other modes which offer better performance, however I like the data rate / bandwidth trade off of this one.
Cheers, Adrian On 31 March 2016 10:50:07 GMT+01:00, Ross Whenmouth <r...@topwire.co.nz> wrote: >Hi, > >I have implemented Manchester (bi-phase-mark coding), Miller^2 and >Xerxes line coding, transmission through a noisy channel, decoding, >followed by a BER check, in an ~ 1.6 million cell LibreOffice >spreadsheet. > >I would really appreciate it if someone could point me in the direction > >of a good crash course on Octave scripting so that I can have a decent >go at hacking mancyfsk.m etc ;) > > >All three binary line codes tested were confirmed DC-free. I was >surprised that over 100 kbit of random data (20x trials), all three >codes had practically the same BER (about 0.023 for additive flat noise > >at 1.02 times the magnitude of the signal). > >I think that the big advantage of Miller^2 and Xerxes over Manchester >are that they consume half the bandwidth of Manchester, meaning that we > >could either avoid the noisier upper half of the FM channel, or >alternately, we could send bits twice as fast in the same bandwidth as >a >Manchester line code but a with 1/2 rate FEC. > > >The channel in my spreadsheet has flat noise added to it (flat >distribution of random numbers, not Gaussian) and I have not attempted >to filter the channel or simulate FM modulation/demodulation. However, >the same random data stream and channel noise is used for each line >code >under test, so I believe that it is still a fair test of the relative >performance of the different line codes. I think that my SNR >calculation >is buggy because I have to select -0.2 dB SNR to get a BER of about >0.023. > >Anyone who is interested can access my spreadsheets on Google Drive: >https://drive.google.com/open?id=0BzNXZIXmo93lS2FtZTFOdk5OekU >"line code stats.ods" can be viewed online through Google Docs, >however, >"line codes.ods" is too big and you will need to download it if you >want >to open it (no, it does not use macros). > > >73 ZL2WRW >Ross Whenmouth > >------------------------------------------------------------------------------ >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=278785471&iu=/4140 >_______________________________________________ >Freetel-codec2 mailing list >Freetel-codec2@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/freetel-codec2 -- Sent from my Android device with K-9 Mail. Please excuse my brevity. ------------------------------------------------------------------------------ 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=278785471&iu=/4140 _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2
