On Coded Caching in the Overloaded MISO Broadcast Channel

TL;DR

This paper explores combining coded caching with spatial multiplexing in overloaded MISO broadcast channels, proposing a new scheme that improves delivery time and reduces CSIT needs.

Contribution

It introduces a novel scheme that integrates coded caching and spatial multiplexing, outperforming existing methods in overloaded MISO BC scenarios.

Findings

Reduced delivery time compared to existing schemes

Lower CSIT requirements for the proposed scheme

Enhanced multicasting opportunities through combined approach

Abstract

This work investigates the interplay of coded caching and spatial multiplexing in an overloaded Multiple-Input-Single-Output (MISO) Broadcast Channel (BC), i.e. a system where the number of users is greater than the number of transmitting antennas. On one hand, coded caching uses the aggregate global cache memory of the users to create multicasting opportunities. On the other hand, multiple antennas at the transmitter leverage the available CSIT to transmit multiple streams simultaneously. In this paper, we introduce a novel scheme which combines both the gain derived from coded-caching and spatial multiplexing and outperforms existing schemes in terms of delivery time and CSIT requirement.