A PEG Construction of LDPC Codes Based on the Betweenness Centrality Metric

• Main Authors: BHURTAH-SEEWOOSUNGKUR, I., CATHERINE, P. C., SOYJAUDAH, K. M. S.
• Format: Article
• Language: English
• Published: Stefan cel Mare University of Suceava 2016-05-01
• Series: Advances in Electrical and Computer Engineering
• Subjects: AWGN channels; block codes; channel coding; error correction codes; parity check codes
• Online Access: http://dx.doi.org/10.4316/AECE.2016.02012

Progressive Edge Growth (PEG) constructions are usually based on optimizing the distance metric by using various methods. In this work however, the distance metric is replaced by a different one, namely the betweenness centrality metric, which was shown to enhance routing performance in wireless mesh networks. A new type of PEG construction for Low-Density Parity-Check (LDPC) codes is introduced based on the betweenness centrality metric borrowed from social networks terminology given that the bipartite graph describing the LDPC is analogous to a network of nodes. The algorithm is very efficient in filling edges on the bipartite graph by adding its connections in an edge-by-edge manner. The smallest graph size the new code could construct surpasses those obtained from a modified PEG algorithm - the RandPEG algorithm. To the best of the authors' knowledge, this paper produces the best regular LDPC column-weight two graphs. In addition, the technique proves to be competitive in terms of error-correcting performance. When compared to MacKay, PEG and other recent modified-PEG codes, the algorithm gives better performance over high SNR due to its particular edge and local graph properties.