POLAR Decoder SC List Definition

Successive cancellation list (SCL) decoder for polar codes.

Decoder is based on Tal, Vardy "List Decoding of Polar Codes", 2012 LLR version: Balatsoukas-Stimming, Parizi, Burg "LLR-based Successive Cancellation List Decoding of Polar Codes", 2015.

Block expects float input with bits mapped 1 --> 1, 0 --> -1

Or: f = 2.0 * bit - 1.0

Parameters

Parallelism

For parallel execution of multiple instances of the block (more info is needed on this)

Dimension 1

For parallelism

Dimension 2

For parallelism

Maximum List size

Caps number of followed decoding paths.

Block size (N)

Codeword size. MUST be a power of 2.

#Info Bits (K)

Represents the number of information bits in a block. Also called frame_size. <= block_size

Frozen Bit Positions

Integer vector which defines the position of all frozen bits in a block. Its size MUST be equal to block_size - num_info_bits. Also it must be sorted and every position must only occur once.

Frozen Bit Values

Holds an unpacked byte for every frozen bit position. It defines if a frozen bit is fixed to '0' or '1'. Defaults to all ZERO.

Example Flowgraph

Insert description of flowgraph here, then show a screenshot of the flowgraph and the output if there is an interesting GUI. Currently we have no standard method of uploading the actual flowgraph to the wiki or git repo, unfortunately. The plan is to have an example flowgraph showing how the block might be used, for every block, and the flowgraphs will live in the git repo.

Source Files

C++ files

[1]

Common code

Public header files

[2]

Block definition

[3]