OFDM Based Bistatic Integrated Sensing and Communication: Sensing Beyond CP Limit

This work investigates a bistatic OFDM-based integrated sensing and communication (ISAC) system under a single-target scenario, considering both line-of-sight (LOS) presence and LOS blockage cases. A sliding window-based sensing receiver architecture is proposed to extend the intersymbol interference (ISI)-free sensing range beyond the cyclic prefix (CP) duration by exploiting pilot symbols embedded in the time-frequency grid. The performance of the proposed receiver is evaluated in terms of range and velocity estimation accuracy and is compared against the Cramer-Rao bounds (CRBs) for the bi-static ISAC setting. Numerical results confirm that the proposed method achieves estimation performance that closely approaches the CRBs in the high signal-to-noise ratio (SNR) regime.

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

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.