If the input value is '0' it should not really affect the error
since it's just an indecisive bit. We accept this either an internal
'0' (generated via puncture) or as an external '0' (generated via an
external puncturing scheme). A real received bit should never be '0',
it's always gonna be closer to 1 or the other value ...
(thanks to mad@auth.se on the ML for the idea)
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Far from perfect but suits our need thus far.
The viterbi with softbit input is quite cpu-intensive. Since
most received bursts are often mostly error free, you could
use a less cpu intensive algorithm (Fano ?) and with hard bit
input. Then only switch to viterbi soft bit input if the channel
is bad enough to justify it.
Soft output is not implemented as its usefulness for the block
coding is limited.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>