WSJT-x signal processing versus RTTY decoding in Fldigi? #decode


Bruce KX4AZ
 

I have always been in awe over the signal processing and error correction techniques used in the assorted WSJT-x modes....and my curiosity compels me to ask...

I wonder if any of these techniques could be applied with other modes like RTTY in programs like Fldigi.  Of course, RTTY has no error correction by design, but what about the other "tricks" used by WSJT-x for weak signal decoding?  Or do programs like Fldigi already have the latest and greatest decoding algorithms built in for weaker RTTY signals?

If this query doesn't belong in this forum, would appreciate a "re-direct" sent my way.


Bill Somerville
 

On 19/07/2021 19:26, Bruce KX4AZ wrote:
I have always been in awe over the signal processing and error correction techniques used in the assorted WSJT-x modes....and my curiosity compels me to ask...

I wonder if any of these techniques could be applied with other modes like RTTY in programs like Fldigi.  Of course, RTTY has no error correction by design, but what about the other "tricks" used by WSJT-x for weak signal decoding?  Or do programs like Fldigi already have the latest and greatest decoding algorithms built in for weaker RTTY signals?

If this query doesn't belong in this forum, would appreciate a "re-direct" sent my way.
Hi Bruce,

simple answer, if you want weak signal efficiency then don't start with something like BAUDOT using FSK at 45.5 baud.

Of course authors of soundcard RTTY decoders have explored and implemented all sorts of smart filtering and other DSP techniques to get the best decoding performance they could. There is probably very little leeway for much better performance without changing the protocol in some way.

73
Bill
G4WJS.