SSB sometimes wins because the brain picks up the slack. like with a 0.5
second fade.
In my opinion, for HF paths, to be broadly useful , voice DV modes need
to pass an HF fading simulator, targeted at vertical incidence work, and
bear in mind, that the channel profiles are quite different for
Equatorial, Mid latitude and high latitude locations. And they must have
minimal conversational delay, , < 0.25 seconds.
take a look at
https://www.itu.int/dms_pubrec/itu-r/rec/f/R-REC-F.1487-0-200005-I!!PDF-E.pdf
several languages :
https://www.itu.int/rec/R-REC-F.1487-0-200005-I/en
This article, is useful for its 127 excellent references,
https://link.springer.com/article/10.1007/s11235-017-0287-2#CR38
and has some excellent channel profile references .
From the DRM spec, Annex B Definition of channel profiles
Channel 6, path 4
delta delay : 6mS, path gain RMS = 0.0625, dopplershift : 3.6Hz, dopper
spread 7.2Hz
Some paths are worse than that .. especially vertical incidence paths
what have values almost triple the above numbers....
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Freetel-codec2 mailing list
Freetel-codec2@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/freetel-codec2
