On the Construction and Performance of LDPC Codes

Abstract

Low-Density-Parity-Check (LDPC) codes are excellent error correcting codes performing very close to the Shannon’s limit, enabling efficient and reliable communication. Ever since their importance was known, a lot of research has gone into the construction/designing of efficient LDPC codes. Many different construction methods have been proposed so far. This paper explores some of these construction methods and includes their performance results on the Additive White Gaussian Noise (AWGN) channel. In particular, LDPC code construction using cage graphs and permutation matrices are investigated. Irregular LDPC codes have been constructed from regular LDPC codes using an expansion method, followed by their code rate comparison.