Protograph-Based Raptor-Like LDPC Codes for Rate Compatibility With Short Blocklengths
This paper presents a new class of rate-compatible LDPC codes, Protograph-Based Raptor-Like (PBRL) codes. The proposed PBRL codes are jointly decodable with an iterative belief propagation decoder. As with Raptor codes, additional parity bits can be easily produced by exclusive- or operations on the pre-coded bits, providing extensive rate compatibility. This paper provides a design procedure that optimizes this class of rate-compatible LDPC codes. The new PBRL codes outperform 3GPP rate-compatible turbo codes with the same short blocklength at high SNR and show no sign of an error floor at the FER region of 10-7.