Decentralized Multi-Antenna Coded Caching with Cyclic Exchanges

TL;DR

This paper introduces decentralized coded caching strategies for multi-antenna base stations, proposing cyclic-exchange protocols and new coding schemes that improve content delivery efficiency in wireless networks.

Contribution

It develops novel decentralized coding schemes for multi-antenna systems, including a two-user broadcast method and a cyclic-exchange protocol, with closed-form rate expressions.

Findings

Cyclic-exchange protocol performs nearly as well as multi-user schemes.

New coding scheme works effectively with only two-user broadcasts.

Closed-form rate expressions are derived for various coding strategies.

Abstract

This paper considers a single cell multi-antenna base station delivering content to multiple cache enabled single-antenna users. Coding strategies are developed that allow for decentralized placement in the wireless setting. Three different cases namely, max-min multicasting, linear combinations in the complex field, and linear combinations in the finite field, are considered and closed-form rate expressions are provided that hold with high probability. For the case of max-min fair multicasting delivery, we propose a new coding scheme that is capable of working with only two-user broadcasts. A cyclic-exchange protocol for efficient content delivery is proposed and shown to perform almost as well as the original multi-user broadcast scheme.