Sensing and Channel Estimation for OTFS-ISAC System With Reduced PAPR

In this letter, we propose a delay-Doppler domain pilot structure for an orthogonal time frequency space-integrated sensing and communication (OTFS-ISAC) system that addresses the issue of high peak-to-average power ratio in the existing structures. Then, we propose a norm-zero-modified generalized maximum Versoria criterion ( $l_{0}$ -MGMVC)-based channel estimator at the communication receiver that is robust under fractional channel Doppler and ghost paths. At the sensing receiver, we propose a mean squared error-based target range and speed estimator. The derived analytical results and simulations indicate that the proposed pilot structure, channel estimator, and sensing parameter estimator outperform the existing state-of-the-art schemes.