Fundamental limits of caching: Improved rate-memory trade-off with coded prefetching

Abstract

We consider a cache network, in which a single server is connected to multiple users via a shared error free link. The server has access to a database with $N$ files of equal length $F$ , and serves $K$ users each with a cache memory of MF bits. A novel centralized coded caching scheme is proposed for scenarios with more users than files $N\leq K$ and cache capacities satisfying $({1}/{K})\leq M\leq ({N}/{K})$ . The proposed scheme outperforms the best rate-memory region known in the literature if $N\leq K\leq (({N^{2}+1})/{2})$ .