3.2.4.5.1. Polar MK Encoder parameters¶
3.2.4.5.1.1. --enc-type¶
Type: text Allowed values: POLAR_MKAZCWCOSETUSERDefault: POLAR_MKExamples: --enc-type AZCW
Select the encoder type.
Description of the allowed values:
| Value | Description |
|---|---|
POLAR_MK |
Select the standard Polar MK encoder. |
AZCW |
See the common --enc-type parameter. |
COSET |
See the common --enc-type parameter. |
USER |
See the common --enc-type parameter. |
3.2.4.5.1.2. --enc-sys¶
Enable systematic encoding. By default the encoding process is non-systematic.
3.2.4.5.1.3. --enc-pc-kernel¶
Type: list of (list of (boolean:including set={0|1}):limited length [1;inf]), elements of same length Default: "10,11"Examples: --enc-pc-kernel "111,101,011"
Set the polar code kernel (squared matrix only).
The Kronecker powers of the kernel matrix \(T_s\) defines the \(G\) generator matrix. The frame size \(N\) can only be a power of the matrix size \(s\). For traditional Polar codes \(s = 2\).
Note
This parameter can only be used to define mono-kernel polar codes.
3.2.4.5.1.4. --enc-pc-path¶
Type: file Rights: read only Examples: --enc-pc-path example/path/to/the/right/place/
Set the path to a file containing the polar code description (kernels definition and stages).
An ASCII file is expected:
# number of different kernels
2
# dimension of kernel 0
2
# kernel 0
1 0
1 1
# dimension of kernel 1
3
# kernel 1
1 1 1
1 0 1
0 1 1
# number of stages
5
# type of kernel per stage
0 0 0 0 1
The previous file describes a Polar MK code which is build from the following Kronecker product: \(G_{48} = T_2 \otimes T_2 \otimes T_2 \otimes T_2 \otimes T_3\) with \(N = 2 \times 2 \times 2 \times 2 \times 3 = 48.\)
Note
When this parameter is used it overrides the --enc-pc-kernel parameter.
Note
This parameter is the only way to define multi-kernel polar codes.
3.2.4.5.1.5. --enc-fb-gen-method¶
Type: text Default: GAAllowed values: GAGAAFILEExamples: --enc-fb-gen-method FILE
Select the frozen bits generation method.
Description of the allowed values:
| Value | Description |
|---|---|
GA |
Select the GA method from [Tri12]. |
GAA |
Select the GA method from [Tri12] (works only for Arikan mono-kernel polar codes). |
FILE |
Read the best channels from an external file, to use with the --enc-fb-awgn-path parameter. |
Note
When using the FILE method, the frozen bits are always the same
regardless of the SNR value.
3.2.4.5.1.6. --enc-fb-awgn-path¶
Type: file Rights: read only Examples: --enc-fb-awgn-path example/path/to/the/right/place/
Set the path to a file or a directory containing the best channels to select the frozen bits.
An ASCII file is expected, for instance, the following file describes the most reliable channels optimized for a codeword of size \(N = 8\) and for an AWGN channel where the noise variance is \(\sigma = 0.435999\):
8
awgn
0.435999
7 6 5 3 4 2 1 0
Given the previous file, if we suppose a Polar code of size \(N = 8\) with
\(K = 4\) information bits, the frozen bits are at the 0, 1, 2, 4
positions in the codeword. The strategy is to freeze the less reliable channels.
Warning
The FILE frozen bits generator expects a file and not a
directory.
3.2.4.5.1.7. --enc-fb-dump-path¶
Type: folder Rights: write only Examples: --enc-fb-dump-path example/path/to/the/right/place/
Set the path to store the best channels.
Note
Works only for the GA and GAA frozen bits generation methods.
3.2.4.5.1.8. --enc-fb-noise¶
Type: real number Examples: --enc-fb-noise 1.0
Select the noise for which the frozen bits will be optimized.
3.2.4.5.1.9. References¶
| [Tri12] | (1, 2) P. Trifonov. Efficient design and decoding of polar codes. IEEE Transactions on Communications (TCOM), 60(11):3221–3227, November 2012. doi:10.1109/TCOMM.2012.081512.110872. |