Multiple-rate multiple-length QC-LDPC codes design with near shannon limit performance

Multiple-rate multiple-length LDPC codes with near Shannon limit performance at each rate are demanded in the next generation digital television terrestrial broadcasting (DTTB) systems. Row-Combining with Edge Variation (RCEV) codes, which generate higher rate codes by linearly combining the rows of parity-check matrix of a lower rate mother code, are rate-compatible with constant code length and simple hardware decoder architecture. This paper proposes an improved multi-rate scheme called Row-Combing-Splitting with Edge Variation (RCSEV) codes, where row splitting is introduced to improve the freedom of code construction at each rate. Multi-length code design can also be achieved by RCSEV codes with Quasi-Cycle (QC) structure. Finally, a set of multi-rate, multi-length candidate codes are proposed for the next generation DTTB systems. A comparison with DVB-S2 LDPC codes is performed and the better performance of our proposed code is validated via both extrinsic information transfer (EXIT) chart analysis and bit error rate (BER) simulations. Hardware implementation result demonstrates that the complexity of the multi-rate decoder is close to that of single rate counterpart.