On the Performance of Holographic ISAC

A framework of holographic MIMO (HMIMO) based integrated sensing and communications (ISAC), i.e., holographic ISAC (HISAC), is proposed. An accurate spherical wave-based model is utilized to characterize sensing link. The spacial correlation introduced by the densely spaced antennas of the HMIMO is incorporated when modeling the communication channel. Based on the proposed framework, closed-form expressions are derived for sensing rates (SRs), communication rates (CRs), and outage probabilities under different beamforming strategies to investigate fundamental information theoretical limits for HISAC. Further insights are gained by examining high signal-to-noise ratio slopes and diversity orders. A Pareto optimal design is proposed to characterize the attainable SR-CR region. Numerical results reveal that HISAC outperforms the conventional MIMO based ISAC and the HMIMO based frequency-division sensing and communications system in terms of both sensing and communications.