Subpacketization-Beamformer Interaction in Multi-Antenna Coded Caching

TL;DR

This paper investigates how the interaction between beamformer complexity and subpacketization affects the achievable rate in multi-antenna cache-enabled communications at low-SNR, revealing that joint increases can improve performance.

Contribution

It provides a mathematical analysis showing the contrasting effects of subpacketization on simple versus complex beamformer structures at low-SNR.

Findings

Simplistic beamformers see degraded rates with increased subpacketization.

Complex beamformers benefit from increased subpacketization for better rates.

Jointly increasing beamformer complexity and subpacketization improves low-SNR performance.

Abstract

We study the joint effect of beamformer structure and subpacketization value on the achievable rate of cache-enabled multi-antenna communications at low-SNR. A mathematical approach with low-SNR approximations is used, to show that using simplistic beamformer structures, increasing subpacketization degrades the achievable rate; in contrast to what has been shown in the literature for more complex, optimized beamformer structures. The results suggest that for improving the low-SNR rate, subpacketization and beamformer complexity should be jointly increased.