On the Performance of Dual-Antenna Repeater Assisted Bi-Static MIMO ISAC

TL;DR

This paper analyzes a repeater-assisted bi-static MIMO ISAC system, highlighting how repeaters can enhance detection and communication performance while managing associated interference and noise.

Contribution

It introduces a framework that balances sensing and communication trade-offs and demonstrates benefits of deploying repeaters in hot-spot areas.

Findings

Higher detection probability with lower radar-cross-section variance using repeaters.

Repeaters improve sensing and downlink communication performance.

Careful precoder design mitigates interference effects.

Abstract

This paper presents a framework for target detection and downlink data transmission in a repeater-assisted bi-static integrated sensing and communication system. A repeater is an active scatterer that retransmits incoming signals with a complex gain almost instantaneously, thereby enhancing sensing performance by amplifying the echoes reflected by the targets. The same mechanism can also improve downlink communication by mitigating coverage holes. However, the repeater introduces noise and increases interference at the sensing receiver, while also amplifying the interference from target detection signals at the downlink users. The proposed framework accounts for these sensing-communication trade-offs and demonstrates the potential benefits achievable through a carefully designed precoder at the transmitting base station. In particular, our finding is that a higher value of probability of detection can be attained with considerably lower target radar-cross-section variance by deploying repeaters in the target hot-spot areas.