Multi-TRP Assisted UAV Detection in 3GPP 5G-Advanced ISAC Network

2026-04-28

AI Summary

This work addresses the degraded drone detection performance in UMa-AV scenarios caused by limited angular coverage, occlusion, and restricted field of view when using a single TRP. Building upon the 3GPP 5G-Advanced ISAC framework, the paper proposes a monostatic sensing architecture assisted by multiple TRPs, which leverages spatial diversity to fuse independently acquired sensing data from each TRP. A voting threshold mechanism is designed to jointly suppress missed detections and false alarms, complemented by a low-overhead scheduling strategy. The system is validated for the first time under the 3GPP-standardized UMa-AV channel model and Release 19 evaluation framework. Results show that the dual-TRP configuration significantly enhances target observability, reduces false alarms, and tightens localization error, while extending the sensing refresh interval from 128 ms to 1 s and decreasing overhead from 29% to approximately 3.7%, thereby meeting 3GPP performance requirements.

Abstract

ISAC is currently being standardized within the 3GPP New Radio (NR) to enable cellular infrastructure to perform sensing using existing communication waveforms. While standardization is progressing, practical deployment may be limited by scenario-dependent observability constraints. For example, in UMa-AV scenarios, sensing with a single TRP can be affected by restricted angular coverage, partial blockage, and limited field of view, which may degrade detection reliability in three-dimensional UAV environments. For this reason, multi-TRP solutions have been suggested to improve spatial diversity and sensing robustness. In this paper, we present a system-level investigation of multi-TRP assisted monostatic sensing for UAV detection under standardized 3GPP UMa-AV channel assumptions and Release 19 evaluation parameters. We propose a spatial diversity fusion framework and evaluate the achievable performance of a 3GPP network by combining the measurements obtained independently at different TRP. Extensive evaluations demonstrate that multi-TRP assistance improves target observability, reduces spurious detections, and tightens localization error distributions at the cost of additional sensing overhead due to the need for multiple TRPs to periodically allocate radio resources for sensing measurements. In the evaluated scenario, results show that a voting threshold of two assisting TRPs achieves an optimal trade-off between miss detection probability and false alarm suppression, meeting 3GPP performance objectives. Furthermore, we quantify the sensing overhead and show that proper system design, tuned to the application requirements, can substantially reduce its impact: for example, extending the sensing refresh interval beyond the 128 ms coherent processing interval to 1 s reduces the effective overhead from 29 % to approximately 3.7 %, enabling more scalable network deployment.

Problem

• UAV detection
• ISAC
• multi-TRP
• observability constraints
• 3GPP 5G-Advanced

Innovation

• multi-TRP sensing
• ISAC
• spatial diversity fusion
• UAV detection
• sensing overhead