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arXiv · 1809.09422

Coded Caching with Shared Caches: Fundamental Limits with Uncoded Prefetching

Emanuele Parrinello·Ayşe Ünsal·Petros Elia
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Abstract

The work identifies the fundamental limits of coded caching when the K receiving users share {\Lambda}$\leq$ K helper-caches, each assisting an arbitrary number of different users. The main result is the derivation of the exact optimal worst-case delivery time - under the assumption of uncoded cache placement - for any user-to-cache association profile, where each such profile describes how many users are helped by each cache. This is achieved with a new information-theoretic converse that is based on index coding and which proves that a simple XOR-shrinking-and-removal coded-caching scheme is optimal irrespective of the user-to-cache association profile. All the results also apply directly to the coded caching problem with multiple file requests.

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Emanuele Parrinello, Ayşe Ünsal, Petros Elia. 2018-09-25. Coded Caching with Shared Caches: Fundamental Limits with Uncoded Prefetching. https://arxiv.org/abs/1809.09422

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