kaira.models.fec.decoders.BaseBlockDecoder

Inheritance diagram for BaseBlockDecoder

class kaira.models.fec.decoders.BaseBlockDecoder(encoder: T, *args: Any, **kwargs: Any)

Bases: BaseModel, Generic[T], ABC

Base class for block code decoders.

This abstract class provides a common interface and functionality for all types of block code decoders. It serves as a foundation for specific implementations like syndrome decoders, maximum likelihood decoders, algebraic decoders, and soft-decision decoders.

The class uses a generic type parameter T to ensure type safety when pairing encoders with their corresponding decoders. This allows the compiler to catch type mismatches at development time rather than during runtime.

encoder

The encoder instance associated with this decoder, providing access to code parameters and encoding/syndrome calculation methods

Type:

T

Parameters:

• encoder (T) – The encoder instance for the code being decoded

• *args – Variable positional arguments passed to the base class

• **kwargs – Variable keyword arguments passed to the base class

Note

All concrete implementations must override the forward method to implement specific decoding algorithms. Decoders may operate on hard-decision (binary) or soft-decision (real-valued reliability information) inputs depending on their implementation.

Methods

__init__	Initialize the block code decoder with an encoder instance.
forward	Decode received codewords to recover the original messages.

Attributes

code_dimension	Get the code dimension (k).
code_length	Get the code length (n).
code_rate	Get the code rate (k/n).
redundancy	Get the code redundancy (r = n - k).

__init__(encoder: T, *args: Any, **kwargs: Any)

Initialize the block code decoder with an encoder instance.

The encoder provides essential information about the code parameters and may be used by the decoder to perform syndrome calculations or other encoding-related operations during the decoding process.

property code_length: int

Get the code length (n).

The code length is the total number of bits in each codeword, including both information bits and redundancy bits.

Returns:

The length of the code (number of bits in a codeword)

property code_dimension: int

Get the code dimension (k).

The code dimension is the number of information bits in each codeword, representing the actual data being transmitted.

Returns:

The dimension of the code (number of information bits)

property redundancy: int

Get the code redundancy (r = n - k).

The redundancy represents the number of parity or check bits added to the information bits to enable error detection and correction.

Returns:

The redundancy of the code (number of parity bits)

property code_rate: float

Get the code rate (k/n).

The code rate is the ratio of information bits to the total bits, indicating the coding efficiency. Higher rates mean more efficient use of the channel but typically lower error correction capability.

Returns:

The rate of the code (ratio of information bits to total bits)

abstractmethod forward(received: Tensor, *args: Any, **kwargs: Any) → Tensor | Tuple[Tensor, Tensor]

Decode received codewords to recover the original messages.

This method implements the decoding algorithm to estimate the original message from a potentially corrupted received codeword. Different decoder implementations will use different algorithms based on the code structure and desired performance characteristics.

Parameters:

• received – Received codeword tensor with shape (…, n) or (…, m*n) where n is the code length and m is some multiple.

• *args – Additional positional arguments for specific decoder implementations.

• **kwargs – Additional keyword arguments for specific decoder implementations.

Returns:

• Decoded tensor containing estimated messages with shape (…, k) or (…, m*k)

• A tuple of (decoded tensor, additional decoding information such as syndromes, reliability metrics, or error patterns)

Return type:

Either

Raises:

ValueError – If the last dimension of received is not a multiple of n.

Note

The decoding may not perfectly recover the original message if the number of errors exceeds the error-correcting capability of the code.