>
> the chance that the error pattern passes the CRC test, that's to say the
> probability that an error goes undetected, is just inversely propoprtional
> to 2^L where L is the CRC polynomial degree.
That's why when a system uses an ECC what really matters to counterfeat
> undetected errors is the CRC polynomial degree, not the polynomial
> coefficents unless their are choosen in a very bad way of course.
As an heuristic proof consider that whatever the information message length
M is when you add L CRC bits to the information message there are just 2^M
codewords out of all the possible 2^(M+L) combinations of (M+L) ouput bits.
Therefore, imagined as a point in a binary (M+L) dimensional space, each
codeword is surrounded on average by (2^L)-1 points for which the CRC
doesn't match and the error pattern is detected.
73
Nico / IV3NWV
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
wsjt-devel mailing list
wsjt-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/wsjt-devel
