LDPC Code Construction from Bipartite Kneser Graphs

Abstract

Low density Parity Check (LDPC) codes show excellent characteristics in error correction. It is extensively used in the majority of the modern communication systems. Construction of LDPC code is a challenging task. In the present work, LDPC codes construction is attempted from bipartite Kneser graphs. This is the first time that Kneser graphs are used to construct LDPC codes. A special matrix consisting of very few entries of 1 is used in conjunction with the bipartite Kneser graphs to yield the final LDPC matrix. The codes obtained can be encoded by an approximate lower triangular technique. Also, the codes are four-cycle free, thus giving improved bit error rate performance. The code length and data rate of the codes obtained by the proposed method can be easily altered by choosing the parameters of the Kneser graph suitably.