Frequency-Hopping MIMO Radar-Based Communications: An Overview

Enabled by the advancement in radio frequency technologies, the convergence of radar and communication systems becomes increasingly promising and is envisioned as a key feature of future sixth-generation networks. Recently, the frequency-hopping (FH) MIMO radar has been introduced to underlay dual-function radar-communication (DFRC) systems. Superior to many previous radar-centric DFRC designs, the symbol rate of FH-MIMO radar-based DFRC (FH-MIMO DFRC) can exceed the radar pulse repetition frequency. However, many practical issues, particularly those crucial to achieving effective data communications, are unexplored or unsolved. To promote the awareness and general understanding of the novel DFRC, this article is devoted to providing a timely introduction of FH-MIMO DFRC. We comprehensively review many essential aspects of the novel DFRC: channel/signal models, signaling strategies, modulation/demodulation processing, and channel estimation methods, to name a few. We also highlight major remaining issues in FH-MIMO DFRC and suggest potential solutions to shed light on future research directions.