An Enhanced LDPC Coded Partial Incremental Redundancy HARQ Scheme

An enhanced scheme is proposed for high code rate low density parity check (LDPC) coded partial incremental redundancy (PIR) hybrid automatic repeat request (HARQ). It employs the unequal error protection (UEP) technique for incremental redundancy bits and uses the constellation rearrangement (CoRe) technique for information bits in retransmissions so as to reduce the reliability variances of all encoded bits after soft combining. Simulation results show that the proposed scheme applies to both regular LDPC and irregular LDPC cases and can efficiently improve frame error rate (FER) performance and throughput performance.