VLSI Architectures for Reed–Solomon Codes: Classic, Nested, Coupled, and Beyond

Classic Reed-Solomon (RS) codes and binary Bose-Chaudhuri-Hocquenghem (BCH) codes, which can be considered as a special case of RS codes, are utilized for error correction in numerous systems, such as Flash memories, optical communications, wireless communications, magnetic storage, and deep-space probing. Additionally, RS and BCH codes are interleaved/nested to form high-gain coding schemes, including product and product-like codes and the recent generalized integrated interleaved codes, which are among the most promising candidates to address the hyper-speed and excellent-correction-capability requirements posed by next-generation terabit/s digital communications and storage. In recent developments, RS codes are also split/nested/coupled to form locally recoverable erasure codes and minimum storage regenerating codes that substantially improve the efficiency of failure recovery and enable the continued scaling of large-scale distributed storage. In this article, prominent decoder architectures for classic RS/BCH codes are elaborated and the fundamental mathematical reformulations leading to the architectures are explained. Then the challenges and recent advancements on the decoder design of nested RS/BCH codes are highlighted. Erasure-correcting RS decoders for failure recovery are also briefly discussed. The goal of this article is to provide comprehensive understanding of state-of-the-art VLSI architectures for classic RS/BCH codes and introduce the most recent architectures for new coding schemes built by nesting/coupling RS/BCH codes for emerging applications.