Performance evaluation of low-density parity-check codes

Abstract

LDPC codes were first introduced by Robert Gallager in 1960. Due to the complexity of the codes and the limitations of the then rudimentary computer resources the codes were neglected as a viable form of FEC. LDPC codes were rediscovered by Tanner in 1981 when he generalized the codes and provided a means of graphical representation of LDPC codes. LDPC codes were again neglected until the work of MacKay et al in the mid to late 1990’s resurrected interest in the codes when they were discovered to out perform the then premium Turbo codes. This dissertation specifically describes the process of encoding and decoding LDPC codes and demonstrates the performance comparison between the various types of decoders in terms of bit error rate performance factors.