Protograph-Based LDPC Hadamard Codes

In this paper, we propose a new method to design low-density parity-check Hadamard (LDPC-Hadamard) codes — type of ultimate-Shannon-limit approaching channel codes. The technique is based on applying constraints the check nodes in generalized protograph-based LDPC code, followed by lifting protograph. We name formed protograph-based (PLDPC-Hadamard) also modified Protograph Extrinsic Information Transfer (PEXIT) algorithm for analyzing and optimizing PLDPC-Hadamard code designs. proposed further allows analysis with degree- 1 and/or punctured nodes. find decoding thresholds ranging from ?1.53 dB ?1.42 dB. At BER 10 ?5 , gaps our range 0.40 (for rate = 0.0494) 0.16 0.003). Moreover, error performance comparable that traditional LDPC-Hadamard Finally, performances after puncturing are simulated compared.