Protograph-based Raptor-like LDPC codes with low thresholds

This paper presents a new construction of punctured-node protograph-based Raptor-like (PN-PBRL) codes that is suitable for long-blocklength applications. As with the Raptor codes, additional parity bits can be easily produced by exclusive-OR operations on the precoded bits, providing extensive rate compatibility. The new construction provides low iterative decoding thresholds that are within 0.45 dB of the capacity for all code rates studied, and the construction is suitable for long blocklengths. Comparing at the same information block size of k = 16368 bits, the PN-PBRL codes are as good as the best known AR4JA codes in the waterfall region. The PN-PBRL codes also perform comparably to DVB-S2 LDPC codes even though the DVBi-S2 codes have longer blocklength and outer BCH codes.