First of all, I wish to indicate two points:
- I'm new on this forum. So, if I made some mistakes about forum rules,
precise it.
- I apologize for my english ...
To simplify the subject, in the following, I'll only speak about codec
with rate 1/2.
The aim is to find a method to synchronize decoder with decod/recod and
compare!!
1) No punturing:
In this case, there isn't any problem. I can use a serial syndrome former
applying g1 polynomial on the part of the flow coded with g0, and g0 on
the
part coded with g1. Make SUM%2 and it is obvious. It works very well.
2) Puncturing:
Here I have a problem.
Indeed, some coded bits are not present (of course, ..., they were be
punctured!!).
I tried to unpuncture the incoming coded flow and to inject it in the same
algorithm as unpunctured case. I work in soft bits, so unpunctured bits
equals to 0.
It failed because the syndrome estimation considers that unpunctured bits
are errors. For example, a perfect flow with mask = '1110' (so, rate equal
2/3), the error rate is not to far from 25%!!
Anybody can help me?
Thanks a lot by advance
Please: don't give me links on IEEE site ...
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