Integrated Sensing and Communications: Toward Dual-Functional Wireless Networks for 6G and Beyond

Abstract

As the standardization of 5G solidifies, researchers are speculating what 6G will be. The integration of sensing functionality is emerging as a key feature of the 6G Radio Access Network (RAN), allowing for the exploitation of dense cell infrastructures to construct a perceptive network. In this IEEE Journal on Selected Areas in Communications (JSAC) Special Issue overview, we provide a comprehensive review 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 the multiple facets of ISAC and the resulting performance gains. By introducing both ongoing and potential use cases, we shed light on the industrial progress and standardization activities related to ISAC. We analyze a number of performance tradeoffs between S&C, spanning from information Manuscript

Integrated Human Activity Sensing and Communications

“…3) Scheduling Issue with Target Echoes: In addition to data fusion and device deployment, sensing human activities also impose challenges in resource scheduling on distributed ISAC systems. Since the human echoes could randomly appear in time, frequency, and spatial domains, novel ISAC scheduling algorithms are required to predict the appearance of random echo signals and schedule the echoes in an orderly manner [3]. To this end, some model-based or learning-based algorithms can be applied to echo prediction and detection.…”

“…Integrated sensing and communication (ISAC) can complement existing wireless communication commodity by building-in sensing functionality [2]. As such, wireless devices are able to jointly meet the requirements of sensing and communications, by exploring and balancing all dimensional (spatial/time/frequency) wireless resources, rather than only the standardized pilot structure [3]. Therefore, the future networks and user equipment will not only be capable of wireless communications, but also be perceptive [4], i.e., intelligently sensing targets from reflected and scattered echoes for, e.g., human activity recognition (HAR).…”

Coordinated Power Control for Network Integrated Sensing and Communication

“…Integrated sensing and communications (ISAC) [1]- [3] has been recognized as one of the candidate techniques for sixthgeneration (6G) wireless networks, in which spectrum resources, wireless infrastructures, and communication signals can be reused for the dual role of radar sensing, thus supporting various new applications such as auto-driving and extended reality. Extensive research efforts have been conducted in the literature to enhance both sensing and communication performances by proposing innovative designs, such as waveform design [4], transmit beamforming optimization [5], receive signal processing [6], and resource allocation [2].…”

“…While most prior works focused on the ISAC design in the single-cell scenario with one single ISAC transceiver (see, e.g., [2] and the references therein), recently network ISAC has attracted growing interests, in which multiple ISAC transceivers (e.g., distributed base stations (BSs) in cloud radio access networks (C-RAN)) are enabled to cooperate in performing both distributed radar sensing and coordinated wireless communications (see, e.g., the perceptive mobile network in [7]). Network ISAC is expected to bring various advantages over the conventional single-cell ISAC.…”

Optimal Precoding Design for Monostatic ISAC Systems: MSE Lower Bound and DoF Completion

“…B ENEFITING from the improved spectral-, energy-and hardware efficiency, and the ability to deploy sensing functionality into the current communication networks, the research interest for integrated sensing and communication (ISAC) has arisen in the design of the sixth-generation (6G) systems [1]. Depending on the geographical configurations, current ISAC systems are categorized into three classical configurations [2], i.e., 1) the monostatic deployment that transmits communication signals and then captures the target echoes via the co-located receiver, such as enabling a base station (BS) as a sensor; 2) the bistatic deployment that collects the reflected and scattered echoes from a separated receiver, such as various Wi-Fi sensing applications; 3) the distributed deployment that characterizes a target via signals collected from widely distributed receivers.…”