[Lowfer] Modulation Mode Performance Comparisons

[John Andrews]

Stan,

Your wishes are interesting, but determining BER for all of these modes 
under such dynamic conditions would be nearly impossible. The only real 
way to determine BER is to fire out known patterns and analyze the 
results bit by bit. None of the programs provide that facility, so you 
would be reduced to trying to figure out what went wrong with letters in 
the various coding schemes. Then to try and figure out what the noise 
and signal are doing on a rapidly changing basis would be way beyond my 
capabilities.

It seems to me that the best approach for hobby purposes is to have a 
number of stations using the likely candidate modes on a regular basis, 
and apply group-think to the results. What we lack at the moment, is the 
"number of stations"! Jay and I are only attempting to crack the ice on 
this one, get people interested, and point out some likely paths for 
experimentation. We realize that most of the present operators in this 
band got into it to operate CW, and are not interested in other 
approaches. We both love CW, and use it regularly. But consider two 
applications to the FCC for an Amateur allocation at 600 meters: one 
says it should be a museum, and the other says that the applicants have 
already worked out a regional emergency communication scheme and are 
studying ways to improve it. Hmmmm....

Anyway, for the moment, time is on our side, and we can afford to keep 
trying stuff. If all we do is get some folks interested, then we're 
happy to do that. And frankly, with the small amount of time I have to 
play radio, doing "hard science" is very unlikely.

John A.

Stan wrote:
> Hello John,
> 
> What I would prefer to see, is data to include bit error rates (BER) vs. 
> S/N ratio
> under a variety of propagation conditions.
> That way I can more objectively determine the better modulation scheme 
> for an application.
> 
> While we can estimate BER with Spectrum Lab by looking at the text 
> received,
> we can not directly tie in a S/N or propagation conditions.
> 
> For a block (1 minute) of WSJT JT2 we get reported the signal strength, 
> doppler, and delta Time.
> 
> I would also like to see multiple modulation schemes simultaneously used to
> experience a common propagation condition, not with standing anomalous 
> frequency selective disturbances.
> 
> Stan, W1LE
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