MIMO-ISAC: Performance Analysis and Rate Region Characterization

Abstract: This article analyzes the performance of sensing and communications (S&C) achieved by a multiple-input multiple-output downlink integrated S&C (ISAC) system. Three ISAC scenarios are analyzed, including the sensing-centric design, communications-centric design, and Pareto optimal design. For each scenario, diversity orders and high signal-to-noise ratio slopes of the sensing rate (SR) and communication rate (CR) are derived to gain further insights. Numerical results reveal that \romannumeral1) ISAC achieves the same diversity order as existing frequency-division S&C (FDSAC) techniques; \romannumeral2) ISAC achieves larger high-SNR slopes and a broader SR-CR region than FDSAC.