Date Added: May 2012
An accurate EXtrinsic Information Transfer (EXIT) analysis is developed for protograph Low-Density Parity-Check (LDPC) codes over the Block Fading Channel (BFC). The analysis is thus exploited for analyzing the behavior of distributed protograph LDPC ensembles over block fading relay channels. A novel protograph-based construction of Low-Density Parity-Check (LDPC) codes for the relay channel is proposed, which provides an enhanced unequal error protection (named Unequal Diversity, UD) property. The focus is on quasi-static fading channels and on the high-code-rate (R > 1/2) regimes, for which (according to the Singleton bound) no full diversity can be achieved.