Integrated Sensing and Communication Channel: Measurements, Characteristics, and Modeling

Integrated sensing and communication (ISAC) is considered a promising technique for sixth-generation (6G) systems. The study of the ISAC channel provides the foundations for technical innovation and performance evaluation of the ISAC system. Since the ISAC channel integrates sensing and communication channels, it is necessary to study the new features that emerge under such integration. This article reviews the research progress of the ISAC channel. First, two channel measurement methods, that is, the vector network analyzer (VNA) and the sliding correlation-based (SC-based) sounder, are given; an ISAC channel measurement platform is set up; and current measurement campaigns are summarized. Then, four new features are analyzed, specifically: radar cross-section (RCS), environment effect, self-interference (SI), and shared scatterers. Next, state-of-the-art ISAC channel modeling methodologies are introduced, and how to advance ISAC channel modeling based on these methodologies is discussed. Finally, open issues on the ISAC channel measurement platform and the modeling methods combined with other new features and techniques are analyzed.