High-Rate Constructions of Exact-Repair Regenerating Codes

Regenerating codes are a class of distributed storage codes proposed to reduce the bandwidth consumption in the node repair process. In this paper, we present explicitly a construction of exact-repair regenerating codes, which is a two-layer encoding structure that consists of concatenating an outer scalar maximum distance separable (MDS) code followed by an inner tailor-made MDS array code. These coded symbols are distributed across the storage nodes based on a family of combinatorial objects termed t-designs, and this sophisticated symbol placement enables that a failed node can be repaired by simple data transfer. Furthermore, our proposed regenerating codes generally have a high code rate and extend the parameter values of existing constructions.