# Subpacketization-Rate Trade-off in Multi-Antenna Coded Caching

## TL;DR

This paper introduces a flexible subpacketization scheme for multi-antenna coded caching that balances network efficiency and computational complexity, allowing tailored caching strategies based on network parameters.

## Contribution

It proposes a new scheme enabling adjustable subpacketization levels and introduces an efficiency index to optimize caching performance.

## Key findings

- Larger subpacketization improves efficiency and rate.
- Smaller subpacketization reduces computational complexity.
- Trade-offs between subpacketization level and achievable rate are demonstrated.

## Abstract

Coded caching can be applied in wireless multi-antenna communications by multicast beamforming coded data chunks to carefully selected user groups and using the existing file fragments in user caches to decode the desired files at each user. However, the number of packets a file should be split into, known as subpacketization, grows exponentially with the network size. We provide a new scheme, which enables the level of subpacketization to be selected freely among a set of predefined values depending on basic network parameters such as antenna and user count. A simple efficiency index is also proposed as a performance indicator at various subpacketization levels. The numerical examples demonstrate that larger subpacketization generally results in better efficiency index and higher symmetric rate, while smaller subpacketization incurs significant loss in the achievable rate. This enables more efficient caching schemes, tailored to the available computational and power resources.