Analysis and Design of Staircase Codes for High Bit-Rate Fibre-Optic Communicatio

Low-complexity, iterative hard-decision decoded staircase codes for hard-decision optical transport-networks (OTNs) are designed, with overheads (OH) between 6.25% and 33.3%. Extensive software simulations are performed for all code designs. Net coding gain gaps to hard-decision capacity are found to range from 0.45 dB at 6.25% OH to 1.38 dB at 33.3% OH. All code designs with ≤ 25.0% OH achieved net coding gains within 1.0 dB of hard-decision channel capacity.;The spatially-coupled split-component (SCSC) ensemble is defined, generalizing the structures of staircase and braided block codes. An analysis of SCSC ensembles is given for the binary erasure channel, using the differential equation method of random graph theory and the potential function analysis of spatially-coupled systems. The erasure channel analysis is used to approximate the binary symmetric channel performance. Simulation results show that the analysis gives an accurate prediction of staircase code performance when the size of a staircase block is large (more than 106 bits). Generalizations such as mixture ensembles containing different component codes and SCSC ensembles decoded by beyond bounded-distance component code decoders are also analyzed.;A concatenated coding scheme for soft-decision OTN is proposed, consisting of an inner low-density generator-matrix (LDGM) code and an outer staircase code. The LDGM code is designed while taking into account its decoding complexity, measured as the product of the maximum number of iterations and the number of edges in the code graph. The Pareto frontiers between decoding complexity and net coding gain of the concatenated coding scheme are evaluated for several OTN overheads. Simulations of concatenated coding scheme examples at 20% overhead show the same net coding gains as the best existing soft-decision OTN coding schemes, with up to 68% reduction in decoding complexity.