LPD-Aware Uplink CSI-based 5G NR Downlink Synchronization for Tactical Networks

TL;DR

This paper examines the detectability of 5G NR downlink synchronization signals in tactical networks and proposes a CSI-based beamforming method to enhance stealthiness against eavesdroppers.

Contribution

It introduces a novel uplink CSI-based beamforming approach to reduce detection probability of synchronization signals in tactical 5G networks.

Findings

Detection probability is nearly 100% with standard signals.

CSI-based beamforming significantly lowers eavesdropper detection.

Proposed method maintains legitimate user performance.

Abstract

5G NR is touted to be an attractive candidate for tactical networks owing to its versatility, scalability, and low cost. However, tactical networks need to be stealthy, where an adversary is not able to detect or intercept the tactical communication. In this paper, we investigate the stealthiness of 5G NR by looking at the probability with which an adversary that monitors the downlink synchronization signals can detect the presence of the network. We simulate a single-cell single-eavesdropper scenario and evaluate the probability with which the eavesdropper can detect the synchronization signal block when using either a correlator or an energy detector. We show that this probability is close to $ 100\% $ suggesting that 5G out-of-the-box is not suitable for a tactical network. We then propose utilizing the uplink channel-state-information to beamform the downlink synchronization-signals towards the tactical user-equipment (UE) to lower the eavesdropper detection probability while not compromising the performance of the legitimate tactical UE.