A Novel Hybrid ARQ Scheme Based on LDPC Code Extension and Feedback
The design of an efficient hybrid Automatic Repeat reQuest (ARQ) scheme based on rate compatible Low Density Parity Check (LDPC) codes is considered. It has been shown that extending as well as puncturing of LDPC codes can produce good rate compatible LDPC codes for the additive white Gaussian noise channel. One issue with the traditional LDPC-based hybrid ARQ methods is that the throughput drops off significantly at low Signal-to-Noise Ratios (SNRs). In this paper, the authors introduce a coding scheme which is capable of using puncturing, extending and feedback at the same time to address this issue.