Coded caching: An untapped resource for 6G

Lampiris, Eleftherios; Elia, Petros; Kountouris, Marios
6G Wireless Summit, 17-20 March 2020, Levi, Lapland, Finland

Developments for the next generation of communication systems will require the simultaneous support of a breathtaking amount of devices with heterogeneous needs, ranging from high bitrates and extremely low latency to ultra reliability and ubiquitous connectivity. To date, 5G has experienced tremendous increase in all of the above metrics, but it is envisioned [1] that future demand will put more strain on networks. One resource that wireless systems have not, yet, exploited is the use of caching either at the end users or at the base stations. Enabling 6G with caching has the potential to improve user throughput by storing content closer at the end users and to improve latency through the storing of content at the base stations. Taking advantage of content at the end users has been studied from an information theory perspective in the work of Maddah-Ali and Niesen [2]. The main premise is that one can turn cheap storage at the end-user devices into bandwidth by transmitting cleverly designed multicast messages which satisfy many demands at the same time. Recent developments on Coded Caching have showed that combining multiple antennas with Coded Caching methods can provide a significant boost in the networks. In this tutorial we will focus on the synergy arising between caching enabled users and systems with multiple transmitters. As we will show, a joint consideration of the two resources can not only provide increased bit rates, but also resolve many of the known practical issues that arise, such as the CSI cost of multi-antenna systems and the subpacketization constraint of Coded Caching. The tutorial will take the audience from the fundamental results in Coded Caching, to the discussion of practical considerations, as well as recent advancements that, through the combination of caching with multiple transmitters, can meaningfully transform the delivery of content. As we will illustrate, Coded Caching is a technology that has adequately matured and by being applied to 6G networks can immensely ameliorate their performance. 

Systèmes de Communication
Eurecom Ref:
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