Subpacketization - Beamformer Interaction in Multi-Antenna Coded Caching

Abstract

We study the joint effect of beamformer structure and subpacketization level on the achievable rate of cache-enabled multi-antenna communications. We use appropriate low-SNR approximations, to show that using simple zero-forcing (ZF) beamformers, increasing subpacketization degrades the achievable rate; in contrast to what has been shown in the literature for more complex, optimized beamformers. We also numerically analyze the probability distribution of symmetric rate terms, in order to confirm the validity of mathematical outputs. The results suggest that for improving the content delivery rate at low-SNR, subpacketization level and beamformer complexity should be jointly increased.