)
1
,
0
(
all
for
,
)
,
(
∈
<
x
x
p
x
f
)
1
,
0
(
all
for
),
(
v
)
(
1
∈
<
−
x
x
x
c
p
)
(
v
1
x
p
−
3/ 4/ 10
9
LDPC Codes
EXIT Chart Example
•
Example:
(3,4)-regular LDPC code,
p*
=0.6474
2
1
1
3
2
)
(
)
1
(
1
)
1
(
1
)
(
)
(
)
(
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
=
−
−
=
=
−
−
=
=
−
p
x
x
v
x
px
x
x
c
x
p
x
v
p
p
ρ
λ
3
2
)
(
)
(
x
x
x
x
=
=
ρ
λ
3/ 4/ 10
10
LDPC Codes
EXIT Chart Example
•
Example: (3,4)-regular LDPC code,
p*
=0.6474
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
p
=0.5
p
=0.6
p
=0.7
p
=0.8
p
*
≈
0.6474
3
)
1
(
1
)
(
x
x
c
−
−
=
2
1
1
)
(
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
=
−
p
x
x
v
p
for various
values of
initial erasure
probability
p
