Multi-UAV Tracking Evaluation Using 5G Uplink Signals on an O-RAN ISAC Simulation Testbed

Abstract

We evaluate multi-target detection, association and tracking end to end on an O-RAN simulation testbed built from OpenAirInterface, FlexRIC and Sionna RT that repurposes the 5G NR uplink sounding reference signal as a passive radar waveform, and against what a counter-UAS command-and- control (C2) consumer requires rather than by detection alone. Three UAVs differing in altitude, velocity and radar cross section (-8 to -20 dBsm) fly one bistatic pair with an 8-element planar receive array. Once every target is detected the binding limit is contention, not sensitivity - two targets share one nearest detection in about 74% of coherent processing intervals, and targets are detected far more often than they are tracked. Elevation from that array cannot separate targets sharing a range-Doppler cell, but it decides association in 58% of intervals. Concurrent tracks are exported from the RAN Intelligent Controller (RIC) xApp to a C2 fusion node over a SAPIENT interface carrying a calibrated detection confidence, validated at schema level against a mock fusion node. The evaluation is emulation-only on one geometry with 10 noise seeds, the mechanisms are characterized and analyzed to identify the key factors influencing multi-target tracking performance.