3.2.4.11.2. Turbo DB Decoder parameters¶
3.2.4.11.2.1. --dec-type, -D
¶
Type: text Allowed values: TURBO_DB
CHASE
ML
Default: TURBO_DB
Examples: --dec-type CHASE
Select the decoder algorithm.
Description of the allowed values:
Value | Description |
---|---|
TURBO_DB |
Select the standard Turbo decoder. |
CHASE |
See the common --dec-type, -D parameter. |
ML |
See the common --dec-type, -D parameter. |
3.2.4.11.2.2. --dec-implem
¶
Type: text Allowed values: STD
Default: STD
Examples: --dec-implem STD
Select the decoder implementation.
Description of the allowed values:
Value | Description |
---|---|
STD |
Select the STD implementation. |
3.2.4.11.2.3. --dec-sub-type, -D
¶
Please refer to the RSC DB --dec-type, -D parameter.
3.2.4.11.2.4. --dec-sub-implem
¶
Please refer to the RSC DB --dec-implem parameter.
3.2.4.11.2.5. --dec-crc-start
¶
Type: integer Default: 2
Examples: --dec-fnc-crc-ite 1
Set the first iteration to start the CRC checking.
Note
This parameter requires the Turbo code to be concatenated with a CRC to work, see the CRC parameters.
3.2.4.11.2.6. --dec-fnc
¶
Enable the FNC post processing technique from [TLLeGal+16].
Note
This parameter requires the Turbo code to be concatenated with a CRC to work, see the CRC parameters.
3.2.4.11.2.7. --dec-fnc-ite-m
¶
Type: integer Default: 3
Examples: --dec-fnc-ite-m 2
Set the first iteration at which the FNC is used (c.f the --dec-fnc parameter).
3.2.4.11.2.8. --dec-fnc-ite-M
¶
Type: integer Default: 10
Examples: --dec-fnc-ite-M 6
Set the last iteration at which the FNC is used (c.f the --dec-fnc parameter).
3.2.4.11.2.9. --dec-fnc-ite-s
¶
Type: integer Default: 1
Examples: --dec-fnc-ite-s 2
Set the iteration step for the FNC technique (c.f the --dec-fnc parameter).
3.2.4.11.2.10. --dec-fnc-q
¶
Type: integer Default: 10
Examples: --dec-fnc-q 6
Set the search space for the FNC technique (c.f the --dec-fnc parameter).
3.2.4.11.2.11. --dec-ite, -i
¶
Type: integer Default: 6
Examples: --dec-ite 8
Set the maximal number of iterations in the Turbo decoder. If the Turbo code is concatenated with a CRC and if the CRC is checked, the decoder can stop before making all the iterations.
3.2.4.11.2.12. --dec-sf-type
¶
Type: text Allowed values: ADAPTIVE
ARRAY
CST
LTE
LTE_VEC
Examples: --dec-sf-type ADAPTIVE
--dec-sf-type CST 0.5
Select a SF to be applied to the extrinsic values after each half iteration [VF00]. This is especially useful with the max-log-MAP sub-decoders (BCJR with the \(\max\) approximation): the SF helps to recover a part of the decoding performance loss compare to the MAP algorithm (BCJR with the \(\max^*\) operator).
Description of the allowed values:
Value | Description |
---|---|
ADAPTIVE |
Select the adaptive SF, for the first and second iterations a SF of 0.5 is applied, for the other iterations the SF is 0.85. |
ARRAY |
Select an hard-coded array of SFs (c.f. Table 3.3). |
CST |
Set the same SF to be applied for each iterations. |
LTE |
Select a 0.75 SF. |
LTE_VEC |
Select a 0.75 vectorized SF (faster than LTE ). |
Iteration | Value |
---|---|
1 | 0.15 |
2 | 0.25 |
3 | 0.30 |
4 | 0.40 |
5 | 0.70 |
6 | 0.80 |
7 | 0.90 |
8 | 0.95 |
3.2.4.11.2.14. References¶
[TLLeGal+16] | T. Tonnellier, C. Leroux, B. Le Gal, C. Jégo, B. Gadat, and N. Van Wambeke. Lowering the error floor of double-binary turbo codes: the flip and check algorithm. In International Symposium on Turbo Codes and Iterative Information Processing (ISTC), 156–160. IEEE, September 2016. doi:10.1109/ISTC.2016.7593096. |
[VF00] | J. Vogt and A. Finger. Improving the max-log-MAP turbo decoder. IET Electronics Letters, 36(23):1937–1939, November 2000. doi:10.1049/el:20001357. |