Cryptography Reference
In-Depth Information
Figure 7.22 - (a) PER performance of a double-binary turbo code with
8
states for
blocks of
. Max-Log-
MAP decoding with input samples of 4 bits and 8 iterations. (b) PER performance of
a double-binary turbo code with
12
,
14
,
16
,
53
and
188
bytes. 4-PSK, AWGN noise and rate
2
/
3
16
states for blocks of
188
bytes (4-PSK and 8-PSK)
and
376
bytes (8-PSK), AWGN noise and rate
2
/
3
.
Max-Log-MAP decoding with
input samples of 4 bits (4-PSK) or
5
bits (8-PSK) and
8
iterations.
rates. To simplify, let us say that an 8-state turbo code suces for PERs greater
than
10
−
4
. This is generally the case for transmissions having the possibility
of repetitions (ARQ: Automatic Repeat reQuest). For lower PERs, typical of
broadcasting or of mass memory applications, the 16-state code is highly prefer-
able.
