Bistatic Sensing at THz Frequencies via a Two-Stage Ultra-Wideband MIMO-OFDM System

TL;DR

This paper introduces a two-stage maximum likelihood method for high-resolution, accurate target localization in THz frequency bistatic MIMO-OFDM systems, overcoming ambiguity issues at low SNRs.

Contribution

It proposes a novel two-stage estimation technique that resolves ambiguity in ultra-wideband THz ISAC systems with low complexity.

Findings

Effectively resolves target range ambiguity.

Achieves high accuracy at low SNR.

Demonstrates robustness of the method.

Abstract

Only the chairs can edit The availability of abundant bandwidth at terahertz (THz) frequencies holds promise for significantly enhancing the sensing performance of integrated sensing and communication (ISAC) systems in the next-generation wireless systems, enabling high accuracy and resolution for precise target localization. In orthogonal frequency-division multiplexing (OFDM) systems, wide bandwidth can be achieved by increasing the subcarrier spacing rather than the number of subcarriers, thereby keeping the complexity of the sensing system low. However, this approach may lead to an ambiguity problem in target range estimation. To address this issue, this work proposes a two-stage maximum likelihood method for estimating target position in an ultra-wideband bistatic multiple-antenna OFDM-based ISAC system operating at THz frequencies. Numerical results show that the proposed estimation approach effectively resolves the ambiguity problem while achieving high resolution and accuracy target position estimation at a very low signal-to-noise ratio regime.