A Novel Scheme for Type-II Hybrid ARQ Protocols Using LDPC Codes

In this paper, we propose a novel type-II hybrid ARQ scheme using low density parity check (LDPC) codes. The proposed approach combines low hardware overhead with good decoding performance by using an efficient decoder operating at a much higher rate with a much smaller size parity check matrix. Our scheme makes parts of the previously received data gradually improved until successful decoding of the entire original codeword. We also present a novel efficient framework for constructing rate-compatible LDPC codes applied in our hybrid ARQ scheme. The progressive edge growth (PEG) construction method with zigzag pattern results in linear-time encoding.