Cryptography Reference
In-Depth Information
[1
,
1+
D
+
D
3
]
Figure 5.6 - Tree diagram of the code of polynomials
. The binary pairs
indicate the outputs of the encoder and the values in brackets are the future states.
00
00
00
00
00
(000)
11
11
11
01
01
(001)
10
10
11
11
00
11
00
00
(010)
11
11
01
10
01
10
(011)
01
01
01
01
(100)
10
10
10
10
00
00
(101)
11
11
01
10
01
01
(110)
10
10
00
00
(111)
11
11
d
d
r
i
r
i
d
i
d
i
=0
=1
D
3
]
Figure 5.7 - Trellis diagram of a code with generator polynomials
[1
,
1+
D
+
.
At an instant
i
, the state of a convolutional encoder can take
2
ν
values.
Each of these possible values is represented by a node. With each instant
i
is
associated a states-nodes column and according to input
d
i
, the encoder transits
from a state
s
i
to
s
i
+1
while delivering the coded bits. This transition between
