On the Benefits of Edge Caching for MIMO Interference Alignment

TL;DR

This paper explores how combining caching and interference alignment in MIMO interference channels can enhance data throughput, especially under limited backhaul capacity, by identifying optimal operational regimes and system configurations.

Contribution

It introduces a joint analysis of caching and interference alignment in MIMO systems, deriving transmission rates and identifying when caching provides significant benefits.

Findings

Caching significantly improves throughput in the operational regime.

Optimal number of transmitter-receiver pairs maximizes transmission rate.

Caching reduces backhaul usage, enabling better interference alignment.

Abstract

In this contribution, we jointly investigate the benefits of caching and interference alignment (IA) in multiple-input multiple-output (MIMO) interference channel under limited backhaul capacity. In particular, total average transmission rate is derived as a function of various system parameters such as backhaul link capacity, cache size, number of active transmitter-receiver pairs as well as the quantization bits for channel state information (CSI). Given the fact that base stations are equipped both with caching and IA capabilities and have knowledge of content popularity profile, we then characterize an operational regime where the caching is beneficial. Subsequently, we find the optimal number of transmitter-receiver pairs that maximizes the total average transmission rate. When the popularity profile of requested contents falls into the operational regime, it turns out that caching substantially improves the throughput as it mitigates the backhaul usage and allows IA methods to take benefit of such limited backhaul.