Impact of the Pilot Design for OFDM Based Bi-static Integrated Sensing and Communication System

Abstract: A bistatic milimeter-wave (mmWave) ISAC system utilizing OFDM signaling is considered. For a single-target scnenario, closed-form expressions for the Cramer-Rao bounds (CRBs) of range and velocity estimation are derived for a given pilot pattern. The analysis shows that when the target's range and velocity remain within the maximum unambiguous limits, allocating pilot symbols more frequently in time improves position estimation, while increasing their density in frequency enhances velocity estimation. Numerical results further validate that the least squares (LS) channel estimation approach closely follows CRB predictions, particularly in the high-SNR regime.