The GitHub repository contains source code for the article "Interleaved Cyclic Group Decomposition Length Adaptive MET QC-LDPC Codes" by German Svistunov and Vasiliy Usatyuk, presented at the IEEE International Black Sea Conference on Communications and Networking in June 2019. The code constructs an interleaver to improve performance under 5G eMBB length adaptation for short lengths using k-step recover puncture pattern optimization.

The repository includes two methods:

Baseline Syndrom based approach (one of the trivial approaches, as there exist more efficient MacKay syndrome entropy approaches), implemented in find_puncture_pattern.m k-step recover puncture pattern optimization based on the paper "Rate-compatible punctured low-density parity-check codes with short block lengths" by Jeongseok Ha, Jaehong Kim, D. Klinc, and S. W. McLaughlin, published in IEEE Transactions on Information Theory in 2006. To understand how the code works, run the example.m file, which provides variable nodes to puncturing (P), rates after puncturing nodes in P (Rates), and maximum chain of puncturing depending on random initial nodes. It may be necessary to run the code several times to obtain the maximal rate.

Overall, this repository provides valuable tools for designing puncturing patern for length/rate Adaptive MET QC-LDPC codes and optimizing puncture patterns to improve performance under 5G eMBB length adaptation for short lengths using k-step recovery techniques.

To undestand how it work run example.m [P, Rates, Pairs]=GroupAndSort2(parity_check_matrix,rate_without_puncturing,step_in_rate) P - Variable nodes to puncturing. Rates - rate after punturing nodes in P. Maximal chain of punturing depend from random initial nodes, run several times until get maximal rate.