Method and apparatus for generating low rate turbo codes
An approach is provided for encoding information bits to output a coded signal using turbo code encoding with a low code rate.
1. A method comprising:
encoding information bits to output a coded signal using turbo code encoding with a low code rate, wherein the encoding utilizes constituent encoding having a transfer function:
G
(
D
)
=
[
n
0
(
D
)
d
(
D
)
,
n
1
(
D
)
d
(
D
)
,
…
n
4
(
D
)
d
(
D
)
]
where,
d ( D )=1 +D+D 3
n 0 ( D )=1 +D 2 +D 3
n 1 ( D )=1 +D+D 2 +D 3
n 2 ( D )=1 +D 3
n 3 ( D )=1 +D+D 2
n 4 ( D )=1 +D.
2. The method according to claim 1 , wherein the information bits are encoding by a plurality of constituent encoders utilizing identical transfer functions.
3. The method according to claim 1 , wherein the low code rate includes rate 1/14, rate 1/12, rate 1/10, rate ⅛, rate ⅙, or rate ¼.
4. A device configured to perform the method of claim 1 .
5. A method comprising:
encoding information bits to output a coded signal using turbo code encoding with a low code rate, wherein the encoding utilizes constituent encoding having a transfer function,
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D
)
=
[
n
0
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d
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1
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d
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…
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6
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,
where,
d ( D )=1 +D 3
n 0 ( D )=1
n 1 ( D )=1 +D 2
n 2 ( D )=1 +D 2 +D 3
n 3 ( D )=1 +D+D 2 +D 3
n 4 ( D )=1 +D+D 3
n 5 ( D )=1 +D+D 2
n 6 ( D )=1 +D.
6. The method according to claim 5 , wherein the information bits are encoding by a plurality of constituent encoders utilizing identical transfer functions.
7. The method according to claim 5 , wherein the code rate include rate 1/15.
8. A device configured to perform the method of claim 5 .
9. A system comprising:
a detector configured to receive encoded signals from a plurality of terminals each configured to encode information bits to output a coded signal using turbo code encoding with a low code rate; and
a plurality of turbo code decoders configured to exchange information with the detector to decode the encoded signals, wherein the turbo encoding utilized one of a plurality of transfer functions specified according to the following:
G
(
D
)
=
[
n
0
(
D
)
d
(
D
)
,
n
1
(
D
)
d
(
D
)
,
…
n
4
(
D
)
d
(
D
)
]
where,
d ( D )=1 +D+D 3
n 0 ( D )=1 +D 2 +D 3
n 1 ( D )=1 +D+D 2 +D 3
n 2 ( D )=1 +D 3
n 3 ( D )=1 +D+D 2
n 4 ( D )=1 +D
and
G
(
D
)
=
[
n
0
(
D
)
d
(
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,
n
1
(
D
)
d
(
D
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,
…
n
6
(
D
)
d
(
D
)
]
where,
d ( D )=1 +D 3
n 0 ( D )=1
n 1 ( D )=1 +D 2
n 2 ( D )=1 +D 2 +D 3
n 3 ( D )=1 +D+D 2 +D 3
n 4 ( D )=1 +D+D 3
n 5 ( D )=1 +D+D 2
n 6 ( D )=1 +D.
10. The system according to claim 9 , wherein the low code rate includes rate 1/15, rate 1/14, rate 1/12, rate 1/10, rate ⅛, rate ⅙, or rate ¼.
11. The system according to claim 9 , wherein the terminals operate according to an interleave division multiple access (IDMA) scheme, the system further comprising:
a plurality of interleavers configured to interleave bits from the detector to the decoders; and
a plurality of de-interleavers configured to de-interleave bits from the detector and to output the de-interleaved bits to the decoders.
12. The system according to claim 9 , wherein the detector is further configured to cancel interference from the received encoded signals.
13. A method comprising:
receiving encoded signals from a plurality of terminals each configured to encode information bits to output a coded signal using turbo code encoding with a low code rate; and
decoding the encoded signals, wherein the turbo encoding utilized one of a plurality of transfer functions specified according to the following:
G
(
D
)
=
[
n
0
(
D
)
d
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,
n
1
(
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)
d
(
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)
,
…
n
4
(
D
)
d
(
D
)
]
where,
d(D) = 1 + D + D 3
n 0 (D) = 1 + D 2 + D 3
n 1 (D) = 1 + D + D 2 + D 3
n 2 (D) = 1 + D 3
n 3 (D) = 1 + D + D 2
n 4 (D) = 1 + D.
and
G
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D
)
=
[
n
0
(
D
)
d
(
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)
,
n
1
(
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)
d
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)
,
…
n
6
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D
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d
(
D
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]
where,
d(D) = 1 + D 3
n 0 (D) = 1
n 1 (D) = 1 + D 2
n 2 (D) = 1 + D 2 + D 3
n 3 (D) = 1 + D + D 2 + D 3
n 4 (D) = 1 + D + D 3
n 5 (D) = 1 + D + D 2
n 6 (D) = 1 + D.
14. The method according to claim 13 , wherein the low code rate includes rate 1/15, rate 1/14, rate 1/12, rate 1/10, rate ⅛, rate ⅙, or rate ¼.
15. The method according to claim 13 , wherein the terminals operate according to an interleave division multiple access (IDMA) scheme, the method further comprising:
interleaving bits corresponding to the encoded signals;
de-interleaving bits corresponding to the encoded signals; and
outputting the de-interleaved bits to a plurality of decoders.