Multi-Carrier Wideband OCDM-Based THz Automotive Radar

TL;DR

This paper introduces a novel bistatic THz automotive radar using OCDM multi-carrier waveform, enhancing target detection and estimation by exploiting the coherence bandwidth of the THz channel and combining multi-range/bandwidth returns.

Contribution

It proposes a wideband OCDM-based THz radar system with an optimal multi-frequency signal combination scheme for improved target estimation.

Findings

Enhanced target range and velocity estimation accuracy.

Effective utilization of THz channel coherence bandwidth.

Improved robustness against interference in THz radar signals.

Abstract

Automotive radars at the Terahertz (THz) frequency band have the potential to be compact and lightweight while providing high (nearly-optical) angular resolution. In this paper, we propose a bistatic THz automotive radar that employs the recently proposed orthogonal chirp division multiplexing (OCDM) multi-carrier waveform. As a stand-alone communications waveform, OCDM has been investigated for robustness against interference in time-frequency selective channels. The THz-band path loss, and, hence, radar signal bandwidth, are range-dependent. We address this unique feature through a multi-carrier wideband OCDM sensing transceiver that exploits the coherence bandwidth of the THz channel. We develop an optimal scheme to combine the returns at different range/bandwidths by assigning weights based on the Cramer-Rao lower bound on the range and velocity estimates. Numerical experiments demonstrate improved target estimates using our proposed combined estimation from multiple varied-attenuation THz frequencies.