Type-I HARQ scheme using LDPC codes and partial retransmissions for AWGN and quasi static fading channels

In this paper we present a Type-I HARQ scheme for low density parity check codes (LDPC) using partial retransmissions and diversity combining. The proposed method divides the retransmissions in equal length sub-packets, and applies a power compensation. We demonstrate that the new scheme outperforms, in terms of throughput, the typical diversity combining methods for AWGN and quasi static fading channels, considering BPSK and 16-QAM modulation. Both theoretical and simulation results are presented, with a very good agreement between them. The numerical results show that the gains in terms of throughput, with respect to the typical methods, can be as large as 5 dB.