Quasi-cyclic ldpc code design for block-fading channels

We investigate quasi-cyclic low-density parity-check (QC-LDPC) codes for nonergodic block-fading channels. A construction method for designing QC-LDPC codes is presented. With careful design, the proposed QC-LDPC codes exhibit the same good performance as their corresponding random root- LDPC codes introduced in using iterative belief-propagation (BP) decoding. Moreover, the structure of the proposed QCLDPC codes makes an efficient encoding method possible.