An Overview on Integrated Localization and Communication Towards 6G

Abstract

While the fifth generation (5G) cellular system is being deployed worldwide, researchers have started the investigation of the sixth generation (6G) mobile communication networks. Although the essential requirements and key usage scenarios of 6G are yet to be defined, it is believed that 6G should be able to provide intelligent and ubiquitous wireless connectivity with Terabits per second (Tbps) data rate and sub-millisecond (sub-ms) latency over three-dimensional (3D) network coverage. To achieve such goals, acquiring accurate location information of the mobile terminals is becoming extremely useful, not only for location-based services but also for improving wireless communication performance in various ways such as channel estimation, beam alignment, medium access control, routing, and network optimization. On the other hand, the advancement of communication technologies also brings new opportunities to greatly improve the localization performance, as exemplified by the anticipated centimeter-level localization accuracy in 6G by ultra massive MIMO (multiple-input multiple-output) and millimeter wave (mmWave) technologies. In this regard, a unified study on integrated localization and communication (ILAC) is necessary to unlock the full potential of wireless networks for the best utilization of network infrastructure and radio resources for dual purposes. While there are extensive literatures on wireless localization or communications separately, the research on ILAC is still in its infancy. Therefore, this article aims to give a tutorial overview on ILAC towards 6G wireless networks. After a holistic survey on wireless localization basics, we present the state-ofthe-art results on how wireless localization and communication inter-play with each other in various network layers, together with the main architectures and techniques for localization and communication co-design in current two-dimensional (2D) and future 3D networks with aerial-ground integration. Finally, we outline some promising future research directions for ILAC.

A Tutorial on Terahertz-Band Localization for 6G Communication Systems

“…By adopting ultra-wide bandwidths, multipath signals become resolvable, which improves performance [7]. Nevertheless, the main drawback of shortrange coverage still needs to be tackled [8]. Furthermore, moving to the 400 − 790 THz range of the electromagnetic spectrum, visible light positioning (VLP) has been exploited for localization in visible light communication (VLC) systems.…”

“…Location information can thus reduce the latency and enhance the scalability and robustness of 5G communication systems [1]. This trend continues towards future 6G systems, where localization and communication need to be integrated to achieve ubiquitous connectivity, high data rates, and low latency over a threedimensional (3D) network coverage [8].…”

“…As research on THz technology and 6G networks is rising [25], [26], a few tutorials on 6G systems have already been published [27], [28]. The 6G literature covers topics such as the role of machine-learning methods [29], broadband connectivity [30], and integrated localization and sensing [8]. For THz systems, signal processing techniques [26], defining features [31], and MAC protocols [32] are also addressed.…”

“…Here, latency indicates the update delay; the data rate requirements are also presented for reference. Table III also lists potential THz localization applications and their performance requirements [8], [31], [32], [49]. We note that the applications that require high accuracy and data rates beyond what can be achieved in 5G communication systems are projected to thrive in 6G systems.…”

Integrated Sensing and Communications for V2I Networks: Dynamic Predictive Beamforming for Extended Vehicle Targets

“…In order to measure the angle, one must construct the sample covariance matrix in accordance with the space/time snapshot in(8), where at least Nr samples are required in the nth block. See[24] for more details.…”