Protograph-based Bit-Interleaved Coded Modulation: A Promising Bandwidth-Efficient Design Paradigm

As an established bandwidth-efficient coded modulation technique, bit-interleaved coded modulation (BICM) can achieve very desirable error performance with relatively low implementation complexity for a large number of communication and storage systems. It attracted considerable attention from the research community in the past three decades. The BICM is able to approach Shannon capacity limits over various channels with the use of powerful forward-error-correction (FEC) codes, bit mappers (i.e., interleavers), and high-order modulations. Based on the natural serially-concatenated structure of BICM, iterative demapping and decoding (ID) can be adopted to boost the system performance. Due to the tremendous error-correction capability and simple structures, protograph low-density parity-check (PLDPC) codes and their spatially-coupled (SC) variants have emerged to be a pragmatic and promising FEC solution for BICM systems, and found widespread applications such as deep-space communication, satellite communication, wireless communication, optical communication, and flash-memory-based data storage in recent years. This article offers a comprehensive survey on the state-of-the-art development of PLDPC-coded BICM and its innovative SC variants over a variety of channel models, e.g., additive white Gaussian noise (AWGN) channels, fading channels, Poisson pulse position modulation (PPM) channels, and NAND flash-memory channels. Of particular interest is code construction, constellation shaping, as well as bit-mapper design, where the receiver is formulated as a serially-concatenated decoding framework consisting of a soft-decision demapper and a belief-propagation decoder. In addition, several promising research directions are discussed, which have not been adequately addressed in the current literature.