Project 4 clarification

[Berkin Akin]

Hi all,

There were some questions about the 4-bit log-likelihood values (LLV) for the first iteration. Here is the convention:

Positive LLVs represent the value "0" and negative LLVs represent value "1". Initially if the received 1-bit symbol was "0" then a variable node sends 4-bit LLV of +1 (0001), otherwise if the received 1-bit symbol was "1" then a variable node sends 4-bit LLV of -1 (1111) in the first iteration.

So you can think of

0 = "no clue"
+1 = "weakly 0"
...
+7 "strong 0"
-1 = "weak 1"
...
-7 = "strong 1"

 

I hope this makes it more clear, good luck!

Thanks,

Berkin