Channel-Robust RFF for Low-Latency 5G Device Identification in SIMO Scenarios

TL;DR

This paper presents a channel-robust RFF extraction method using multiple antennas and sub-band segmentation to achieve low-latency, high-accuracy device identification in 5G SIMO scenarios, meeting URLLC latency standards.

Contribution

It introduces a novel RFF extraction technique employing LLDR of CFRs from multiple antennas without additional latency, improving accuracy and speed over existing methods.

Findings

Achieves 96.13% identification accuracy for 30 UEs at 20 dB SNR.

Reduces latency to 0.491 ms, satisfying URLLC requirements.

Effectively mitigates multipath effects without extra signaling.

Abstract

Ultra-low latency, the hallmark of fifth-generation mobile communications (5G), imposes exacting timing demands on identification as well. Current cryptographic solutions introduce additional computational overhead, which results in heightened identification delays. Radio frequency fingerprint (RFF) identifies devices at the physical layer, blocking impersonation attacks while significantly reducing latency. Unfortunately, multipath channels compromise RFF accuracy, and existing channel-resilient methods demand feedback or processing across multiple time points, incurring extra signaling latency. To address this problem, the paper introduces a new RFF extraction technique that employs signals from multiple receiving antennas to address multipath issues without adding latency. Unlike single-domain methods, the Log-Linear Delta Ratio (LLDR) of co-temporal channel frequency responses (CFRs) from multiple antennas is employed to preserve discriminative RFF features, eliminating multi-time sampling and reducing acquisition time. To overcome the challenge of the reliance on minimal channel variation, the frequency band is segmented into sub-bands, and the LLDR is computed within each sub-band individually. Simulation results indicate that the proposed scheme attains a 96.13% identification accuracy for 30 user equipments (UEs) within a 20-path channel under a signal-to-noise ratio (SNR) of 20 dB. Furthermore, we evaluate the theoretical latency using the Roofline model, resulting in the air interface latency of 0.491 ms, which satisfies ultra-reliable and low-latency communications (URLLC) latency requirements.