LDPC Encoder Definition (via Parity Check)

This block creates a LDPC Encoder Definition variable.

This encoder performs a reduced complexity algorithm described by Richardson and Urbanke in Appendix A of their book: Modern Coding Theory. Compared to the block LDPC Encoder Definition (via Generator), this encoder requires orders of magnitude fewer operations to create each codeword. This is accomplished by completing a significant amount of the complex matrix manipulation (including inverse, multiplication, and Gaussian elimination operations) during preprocessing. The disadvantage of this encoder is that it requires a specially formatted matrix. However, GNU Radio includes python scripts to format a standard parity check matrix appropriately for this encoder, as well as a small library of encoding-ready matrices for use.

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

Parity check matrix

The specific format of this parity check matrix is described by Richardson and Urbanke in Appendix A of their book: Modern Coding Theory (ISBN 978-0-521-85229-6). The matrix can be loaded by creating a LDPC Parity Check Matrix block and using its Id in this field.

Example Flowgraph

This flowgraph can be found at [1]

Source Files

C++ files

ldpc_par_mtrx_encoder_impl.cc

Header files

ldpc_par_mtrx_encoder_impl.h

Public header files

ldpc_par_mtrx_encoder.h

Block definition

variable_ldpc_encoder_H.block.yml