New coded caching schemes from placement delivery arrays

TL;DR

This paper introduces new coded caching schemes derived from placement delivery arrays that achieve low subpacketization, reduced memory ratio, and lower transmission rates by better utilizing user cache content.

Contribution

The paper proposes improved coded caching schemes from PDAs that fully exploit user caches, reducing subpacketization and enhancing efficiency over existing methods.

Findings

Two new schemes with low subpacketization and better performance.

Significant reduction in memory ratio and transmission rate.

Enhanced multicasting opportunities through better cache utilization.

Abstract

Coded caching schemes with low subpacketization and small transmission rate are desirable in practice due to the requirement of low implementation complexity and efficiency of the transmission. Placement delivery arrays (PDA in short) can be used to generate coded caching schemes. However, many known coded caching schemes have large memory ratios. In this paper, we realize that some schemes with low subpacketization generated by PDAs do not fully use the users' caching content to create multicasting opportunities and thus propose to overcome this drawback. As an application, we obtain two new schemes with low subpacketizations, which have significantly advantages on the memory ratio and transmission rate compared with the original scheme.