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

TL;DR

This paper proposes a novel OFDM-based bistatic sensing method that extends the ISI-free sensing range beyond the cyclic prefix limit by using a sliding window receiver, achieving near-optimal estimation accuracy in high SNR conditions.

Contribution

It introduces a sliding window-based receiver architecture for bistatic OFDM ISAC systems that surpasses the traditional CP limit for sensing range extension.

Findings

Performance approaches CRBs at high SNR

Effective in LOS and blockage scenarios

Extends sensing range beyond CP limit

Abstract

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.