Hi Tony, Thank you for taking the time to perform the tests.
Our measurement of link quality is done by observing the number (or lack of) repeat requests. More formalised test are required on our side. The Pskmail group certainly report visible improvements in sensitivity and QRM handling which is expected with the FEC and interleaver but at the price of speed of course. In white noise we see a 4 to 5dB improvement over the same bpsk speed but at 1/2 the data rate. Mind you, most links are established on 30M over most likely a single hop (less than 2000 Miles approximately).Would you have a test that simulates these conditions as this is what we targeted in the development of the "robust" modes? It seems that only Darko and I have regular NVIS Pskmail linkups to our respective servers. Best regards, John --- In [email protected], Tony <d...@...> wrote: > > John, > > The NVIS path simulation results show that the PSK-R mode > did not have any advantage over BPSK. In fact, the data > indicates that it may be less robust for NVIS comms. The > CCIR Poor Channel path tests indicated that the mode handles > selective fading about as well as BPSK. > > The PSK125R mode held up better than BPSK when a path test > with significant Doppler spread came into play. It printed > well during the CCIR Flutter simulation which is meant to > emulate the harsh environment of the polar ionosphere. > > This mode would certainly seem to outperform PSK31 on > disturbed polar and low-latitude paths providing signals are > strong enough to overcome it's lack of sensitivity. > > Please have a look at the data John and let us know how the > simulations compare to your NVIS results. > > 73, Tony -K2MO > > > > NVIS Path Simulation > Delay: 7ms > Doppler spread: 1Hz > SNR +10db > > > BPSK125 > ox jumps over the laogtae > quicb bro eo fox jumps over the lazy yog > the quick btown fox jumpYovet the la,y iog > the quick brown foq jumns over the laz1 dog > quick broBn foxjeomps ov the lazy dog > the quick brow fox jumps opoit he lazy dog > the quick*rown fox jumps ovor tre lazy dog > the£uicbro ox jumps over the laBd dog > the quik brown fox ps over th iiPy dng > the quick brE v mps over the lezy do > the qSick brown fox jums ovet the ly dog > the queck breoen fox jeemps over the mazy `p > > PSK125-R > aÌ)ott¢o mlDGta's nceq~M rusrçu SR otpTu > uthe u]vttipg naer the lazy%amseaz > tþ.Úh brown fox jumps over the lazy doSf > th40cd ln fn fkhrecdna ever the lazy bamsea;q > t ck brown fox juo ~dv nWm zy d k pLne > ltg2eRbrown fox ju Jl > 8( hytfwrtdick ¯bdro j mx ls zover t > ttn heqc k brown fox j1Tsy over tttazA ro > tho' ick hN e¢bnumps oviuknftO eaz > h uikrown fox jumps o/lazy dog > o4k Aok brown fog[o hÆ1ereoAt e, > ¶Ùh e oeaainaµLutmps over ta,a ro > the quick broc? fox jumpso.zy doÓ W > > BPSK250 > he quick brn fox ju the la > qui brofox juhe lazy dog > the quick brown fox jps ovee lazy dog > the quick brown foxmps over the lazy dog > thn fox jumGssver t0 lazy dog > the quick brown fox jumps over the Tazy dog > taiquick brown fox jumps oIehe lazy dob > Ek brown fox juks over the l d > the quown fox jumps over the lazy dog > the quick brown fox jumpkver the lazy dog > the quic3 Ir ox jumps over the lazy dog > the quick brown over the lazy dog > the quicwn fox jumps overlazy dog > the nck b?w qr thlazy_og > > PSK250-R > the qnick brown fox jugmp2y'NntheYy og > the qbNªh ¼yüps over the lazy dog > the quick brown foi V over the la se nfg > the quick eethe lazy itte > the qfick brown fox jumps over the l ÝXs A6 > the quick brown fox jumps over the lazy dog > Åmthe quick bePi ¼es over the lfvh > the qnick baieojumps over the lazy dog > the q³yi,8ezE6llhe lazy ½a,i > thu å rown fox jump, ovet¼he lazy dog > the quick bro fox oÈire 2lazy m > > PSK500 > the quick brown fox jumps over tde la>dog > the quick brown fox jumpMover the laQ > he k brown fox jumps over the lazy dog > the quick browA a+¥umps over the laHAç > tt- quick brown ×Å\umer the ltQy dog > the rown fo3uer the la he > brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the qinrfpt#IJox jumps over the lazy dog > the quick brown fox jumps over tme /g > > PSK500-R > i o=st e oaovtüÂuret¶r£ R¦zHelB aeDYt eqepenoKrNfs[5 > Q ateióg= Ng etnjbei cen o'uetdS< tB`üngOGyn ¢m&xNu > ez:;r§uâ7uâ7q Zthe quick brown fox jumps k¹ txnhvtau > f t k¹ ieezZeÀ o¸ni"ç,turi jumps over the lazy dog > the quick brown fo³mo M+ yn > e quick brown fox FQ lloLc beqd ¤²t6SftHka > E Et¿L n t(y~ejodturi Mjumps over the lazy dog > the quidFÅ; fox jumps over the lan ea~e qd ¤d qe gvdhe lan > otM|zF > ck h+lce6 out(¡q,cheaah½2zy dom%e5y7od8turiiezner the lazy > dog > the quick brown fox jumps k¹ txnhRqolonb+ > quick I Iqfox jumps over the lazyetv > > ______________________________ > > > CCIR POOR CHANNEL > Delay: 2ms > Doppler spread: 0.5Hz > SNR +10db > > PSK125 > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > > PSK125-R > he quick browrntutg· (s over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox juntn eJo udzy dog > > PSK250 > he quick brown fox jumps over thel ,te aog > the quick brown fox jumps over the lazy dog > the quick btewo fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > thiquick brown fox jumps over the lazy dog > the quick brown fox julps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > > PSK250-R > the quick brown fox jun iWhglazy dog > the quick brown fox jun iWrg yny dog > the quick broóo ¹t i^bthe lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the qui0g ev<? ¹<t`uo ver the lazy dog > the quick brown fox jumps over the lazy do > > PSK500 > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown äx \upp er the lazy d > omquickro f oarve the ioeoteo oqs n > intohn fox jumps o×r the lazytiog > tme !Stc3 An\s over l»zXÕ°c > 3Snqjumps over the lazy dog > the quick brown fox jumps over the lazy dog > > PSK500-R > ¯iZÑ r the quick brown fox jumps over the lazy dog > the quick brÔu fox jumps over the laFFa h2t tic· iuµ:Îo E] > Úe¬eeE'ty nez +b4rown fox jumps over the lazy dog > o ie;DLi E) r the lazy dog > tibe Nwn fox jumps over the lazy dog > the quick bro 4lTs Ëear the laz Û (y~e > dargown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > > _________________________________________ > > > CCIR: Flutter Fading (Polar Path) > Delay 0.5ms > Doppler Spread: 10Hz > SNR +10db > > PSK125 > the quic®b ownfox j-mps er the laoty d > ehe qeeickrown fox jleeps ower tre lazi dn > the quick brown foÄjumps over the laza dog > e theqcb nrown fo jumps ovet the ly7o > the quick bro fox jum ofer he(tz` a > the quick own fox ]umps over the laPy tog > the qck bro an ×x 6ump1over he lazy dog > the qutc3 b own fox jus over the lazy g > the quick bsown o ox jumps oveCthe lazy dote > > PSK125-R > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lfvhr e > the quick brown fox jumps over the lazy doXl > > PSK250 > the quihk brown fox jumps over t& lazy do a > the quicp brown Õx jumps er tde ¾zydog > the quick brown fox jumps over tae lazy dog > the quick brown fox jumps over the lazy dog > theuick brown fox jumps over the lazy dog > the qeeick brown fox jumps over the lazy asg > thquic0 browAfob jumps over the lazy dog > the quick crown fox jumps over-he la dog > > > PSK250-R > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown Qm jumps over the lazy dog > the quick brown fox jumps over the lazy dg > the quick brown fox jumps over the lazy dog > the quick brown fox jumps lazy dog > the quick brown fox jumps over the lazy dog > > PSK500 > the qui ek brown fox jumps over the lazy dog > the quick brown fo3 jum ovle the lazy dog > the quick rown fox jumps over the lan W deg > t. nuick brown fox jus over the lazy dog > the quick brown n2 jumps over the lazy dog > ±e quick brown fox jlpps over the tPy doi > the queck brown fox jumps over the lazy dog > e the unk brown fox jumps over the lazy Ý > the quic3 brown fox jumps over the l y doae > e quick brown fox jmAo oAerrhe lazy dog > > PSK500-R > he #FcªQt foxsc®r0tver he lazy dog > quick brown fox jumps over the lazy dog > the quick brown fox jumps over the lazy dog > the quick brown fox jumps over the gw&Fye{qdxqùEk df > Da nv4 titst/¥m k brown fox jumps over the lazy dog > he quick brown fox jumps ovexwfeiDn iq#l¸w > the quick brown fox jumps over the lazy n¦y ÷ > eoaziiÒete¥eºs over the lazy dog > tho,¿ @sùni¢t´4lTs j¨ lazy dog > the quick brown fox jumps over the lazy dog > the quick brown foeÖ4lTs over the lazy dog > > > > > > > > > > ----- Original Message ----- > From: vk2eta > To: [email protected] > Sent: Tuesday, January 19, 2010 7:35 PM > Subject: [digitalradio] Re: NVIS Path Simulations - Darko, > 9A2LI > > > > Tony, > > Would it be possible to get the same test for the PSK > "Robust" modes as in the alpha version of Fldigi? > > http://www.w1hkj.com/alpha/fldigi-flarq/ > > I would really like to have an idea of what the simulator > says since we found in practice reasonable NVIS performance > (to our surprise). > > They are basically a BPSK mode with FEC (like PSK63F), but > with an interleaver added for time diversity. > > It would be great to see how the 3 speeds fair (PSK125R, > 250R and 500R) since the interleaver size changes with the > speed. > > Also, regarding Q15X25, if you can run Linux this may be > another option: > http://he.fi/pub/ham/unix/linux/ax25/newqpsk/ > > Regards, > > John (VK2ETA) > > --- In [email protected], Tony <DXDX@> > wrote: > > > > > That is realy nice path test. Can you try few other > modes, > > > some more wide like ALE and Q15X25 ? > > > We experimenting a lot with PSK250/500, with or > without > > > FEC and your path sim. explains us a lot. > > > Experiments are on 80m band with NVIS antennas and > > > 20-100Km distance. > > > 73! Darko 9A3LI > > > > Darko, > > > > I'm glad you found the path tests useful. I've tested > > several modes for NVIS performance using the path > parameters > > recommended by the ITU (see below). This simulation > > represents a mid-latitude NVIS skywave path (7ms delay) > with > > significant ground wave interference. > > > > Please see attached image for the Hellschreiber test > sample. > > The image reveals how NVIS path delays can effect Hell > mode > > reception. Let us know how the simulations compare to > your > > on-air testing and if there's another mode I can run > through > > the simulator for you. > > > > Tony -K2MO > > > > PS: I'm not sure why, but I could not test Q15X25 with > Mixw. > > I'm not aware of another program available for that > mode. > > >
