A Survey on Over-the-Air Computation

TL;DR

This survey reviews over-the-air computation (OAC), highlighting its advantages over traditional separation of communication and computation, and discusses practical schemes, enabling mechanisms, applications, and future research directions.

Contribution

It provides a comprehensive overview of practical OAC methods, comparing schemes, and discussing mechanisms and applications, which was lacking in existing literature.

Findings

OAC can significantly increase computation rates in multi-node wireless networks.

Interference harnessing in OAC outperforms traditional separation methods.

Future research directions include improving reliability and expanding applications.

Abstract

Communication and computation are often viewed as separate tasks. This approach is very effective from the perspective of engineering as isolated optimizations can be performed. However, for many computation-oriented applications, the main interest is a function of the local information at the devices, rather than the local information itself. In such scenarios, information theoretical results show that harnessing the interference in a multiple access channel for computation, i.e., over-the-air computation (OAC), can provide a significantly higher achievable computation rate than separating communication and computation tasks. Moreover, the gap between OAC and separation in terms of computation rate increases with more participating nodes. Given this motivation, in this study, we provide a comprehensive survey on practical OAC methods. After outlining fundamentals related to OAC, we discuss the available OAC schemes with their pros and cons. We provide an overview of the enabling mechanisms for achieving reliable computation in the wireless channel. Finally, we summarize the potential applications of OAC and point out some future directions.