Integrated Sensing and Communications: Towards Dual-functional Wireless Networks for 6G and Beyond

TL;DR

This paper reviews the emerging concept of integrated sensing and communications (ISAC) for 6G networks, discussing its background, applications, performance tradeoffs, signal processing, and future integration prospects.

Contribution

It provides a comprehensive overview of ISAC, including recent advances, standardization efforts, and a vision for deeper integration in future 6G networks.

Findings

ISAC enables dual-functionality in 6G networks.

Tradeoffs exist between sensing and communication performance.

Deep integration of S&C can enhance future wireless networks.

Abstract

As the standardization of 5G is being solidified, researchers are speculating what 6G will be. Integrating sensing functionality is emerging as a key feature of the 6G Radio Access Network (RAN), allowing to exploit the dense cell infrastructure of 5G for constructing a perceptive network. In this paper, we provide a comprehensive overview on the background, range of key applications and state-of-the-art approaches of Integrated Sensing and Communications (ISAC). We commence by discussing the interplay between sensing and communications (S&C) from a historical point of view, and then consider multiple facets of ISAC and its performance gains. By introducing both ongoing and potential use cases, we shed light on industrial progress and standardization activities related to ISAC. We analyze a number of performance tradeoffs between S&C, spanning from information theoretical limits, tradeoffs in physical layer performance, to the tradeoff in cross-layer designs. Next, we discuss signal processing aspects of ISAC, namely ISAC waveform design and receive signal processing. As a step further, we provide our vision on the deeper integration between S&C within the framework of perceptive networks, where the two functionalities are expected to mutually assist each other, i.e., communication-assisted sensing and sensing-assisted communications. Finally, we summarize the paper by identifying the potential integration between ISAC and other emerging communication technologies, and their positive impact on the future of wireless networks.