Coded Caching with Polynomial Subpacketization

Abstract

Consider a centralized caching network with a single server and $K$ users. The server has a database of $N$ files with each file being divided into $F$ packets ($F$ is known as subpacketization), and each user owns a local cache that can store $\frac{M}{N}$ fraction of the $N$ files. We construct a family of centralized coded caching schemes with polynomial subpacketization. Specifically, given $M$, $N$ and an integer $n\ge 0$, we construct a family of coded caching schemes for any $(K,M,N)$ caching system with $F=O(K^{n+1})$. More generally, for any $t\in \{1,2,\cdots ,K-2\}$ and any integer $n$ such that $0\le n\le t$, we construct a coded caching scheme with $\frac{M}{N}=\frac{t}{K}$ and $F\le K\left(\genfrac{}{}{0ex}{}{\left(1-\frac{M}{N}\right)K+n}{n}\right)$.