Low-Complexity Three-Layer GII Encoders Based on a Grouping Strategy

Abstract

Generalized integrated interleaved (GII) codes have emerged as a compelling coding solution for distributed storage systems, as they achieve a favorable tradeoff between error-correcting capability and repair locality. Compared with conventional two-layer GII codes, three-layer GII codes can further enhance locality. However, the three-layer GII encoders entail a recursive dependency where encoding each sub-codeword relies on all preceding ones, leading to significant multiply–accumulate (MAC) overhead and increased hardware complexity. This paper proposes a grouping strategy that fully exploits the inherent hierarchical structure of three-layer GII codes, thereby reducing the number of MAC operations. Based on this strategy, a corresponding encoder architecture is then developed. Synthesis results demonstrate that the proposed encoder can effectively reduce area cost and area-delay product (ADP) by up to 25.5% and 36.7%, respectively.