LDPC

This repository contains code that was developed for my master's thesis on LDPCs. See this MIT post for a nice article on the history of these codes.

This repository is meant mainly for replicability purposes - it is not organized very well. All the code is original, except the functions to read and write .alist matrices, and the AR4JA folders.

How to cite:

If you find something useful, please cite my master's thesis: T. Ortega, "Low Density Parity Check codes," Universitat Politècnica de Catalunya, 2021.

Main folders of interest

gap_code

Contains incidence_matrix_GQ.gap, the GAP script to obtain point-line incidence matrices of different GQs.

graph_tests

Contains several functions that could be of interest. For example:

girth_of_H computes the girth of a binary code from a parity-check matrix.
H2adjacency converts a parity-check matrix to an adjacency matrix.
plot_Tanner_and_H plots the Tanner graph and parity-check matrix shape.

matlab_codes

BIAWGN_capacity numerically accurate BI-AWGN capacity calculator.
generate_regular_H generates a random regular parity-check matrix.
systematic_form transforms a parity-check matrix to systematic (or standard) form, with the convention H = [I P].