Fundamental Limits of Caching: Improved Rate-Memory Tradeoff with Coded Prefetching

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 ≤ K and cache capacities satisfying 1/K ≤ M ≤ N/K . The proposed scheme outperforms the best rate-memory region known in the literature if N ≤ K ≤ N2+1/2 .