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).

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]

Header files

[2]

Public header files

[3]

Block definition

[4]