Multi-access Coded Caching with Optimal Rate and Linear Subpacketization under PDA and Consecutive Cyclic Placement

TL;DR

This paper introduces a new multi-access coded caching scheme with optimal rate and linear subpacketization, utilizing a novel placement strategy and PDA-based analysis to improve caching efficiency in cyclic cache access systems.

Contribution

It proposes a consecutive cyclic placement strategy and constructs PDA-based schemes that achieve near-optimal caching gain with linear subpacketization.

Findings

Achieves optimal rate under certain parameters.

Provides a PDA-based scheme with linear subpacketization.

Outperforms existing schemes in simulations.

Abstract

This work considers the multi-access caching system proposed by Hachem et al., where each user has access to L neighboring caches in a cyclic wrap-around fashion. We first propose a placement strategy called the consecutive cyclic placement, which achieves the maximal local caching gain. Then under the consecutive cyclic placement, we derive the optimal coded caching gain from the perspective of Placement Delivery Array (PDA), thus obtaining a lower bound on the rate of PDA. Finally, under the consecutive cyclic placement, we construct a class of PDA, leading to a multi-access coded caching scheme with linear subpacketization, which achieves our derived lower bound for some parameters; while for other parameters, the achieved coded caching gain is only 1 less than the optimal one. Analytical and numerical comparisons of the proposed scheme with existing schemes are provided to validate the performance.