Novel Decentralized Coded Caching through Coded Prefetching

Abstract

We propose a new decentralized coded caching scheme for a two-phase caching network, where the data placed in user caches in the prefetching phase are random portions of a maximal distance separable (MDS) coded version of the original files. The proposed scheme achieves a better rate memory trade-off by utilizing the reconstruction property of MDS codes which reduces the number of transmissions that are useful only for a small subset of users in the delivery phase. Unlike the previously available coded prefetching schemes, the proposed scheme does not require to have more users than files. The proposed scheme can be viewed as a generalization of the original uncoded prefetching based decentralized coded caching scheme, and likewise, is applicable to various network topologies.