How about using the database of known call signs to improve the ability to decode call signs?
I think this is very good idea and in fact should also be doable.
There are well known algorithms for matching received word against a database of known words.
I believe there is also a database of known contest stations that some of the logging programs are using.
I am still working on the lower level of the stack. Right now my focus has been to improve the classifier part.
This part of software looks at received "dit" "dah" timing, translates them into symbols and runs them through a classfier.
See my latest post in here http://ag1le.blogspot.com/2013/02/probabilistic-neural-network-classifier.html