Fundamental Limits of Caching: Improved Bounds with Coded Prefetching

TL;DR

This paper introduces a new centralized coded caching scheme that improves the rate-memory bounds for networks with more users than files, especially when certain cache capacities are met, enhancing efficiency in data delivery.

Contribution

It presents a novel coded caching scheme that surpasses existing bounds for specific network configurations with more users than files.

Findings

Outperforms previous rate-memory bounds in certain regimes.

Effective for scenarios with N ≤ K ≤ (N^2 + 1)/2.

Enhances data delivery efficiency in cache networks.

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 $\frac{1}{K}\leq M\leq\frac{N}{K}$. The proposed scheme outperforms the best rate-memory region known in the literature if $N\leq K\leq\frac{N^{2}+1}{2}$.