Efficiency comparison of LDPC-LDGM and Raptor codes for PL-FEC with very large block sizes

Abstract

In this paper the performance of LDPC-LDGM codes and Raptor codes is studied and compared in terms of efficiency. LDPC-LDGM and Raptor are FEC codifications that can be applied at packet level. PL-FEC consists in including redundant packets in the transmission to ensure correct reception. Althought these techniques have been previously studied in the literature, they have usually been compared with the performance of small block Reed Solomon codes. This paper presents a novel comparison between the performance of LDPC-LDGM codes and Raptor codes as alternatives for packet level FEC when large codification blocks are needed. The results obtained show that Raptor codes clearly outperform LDPC-LDGM codes in almost all scenarios.