DYNA JOURNAL ENGINEERING

Key words:

millimetre-wave radar, ISAC architecture, autonomous vehicles, roadside units, low-rate design, ADC constraints, FMCW-OFDM waveform, hardware impairments, cross-layer scheduling, V2X communications, URLLC, bistatic sensing

Article type:

COLABORACION/COLLABORATION DAMR

Section:

COLLABORATIONS

Autonomous vehicles must sense their surroundings and exchange data reliably in dense traffic and poor visibility. Many millimetre-wave ISAC proposals assume high-rate converters, near-ideal RF chains, and large compute budgets that do not match production constraints. This paper presents a low-rate ISAC design that co-designs waveform, baseband processing, and scheduling around converter and ECU limits, while using roadside units (RSUs) as cooperative illuminators and relays. The design combines a hybrid FMCW–OFDM frame with impairment-aware estimation that explicitly accounts for phase noise, beam squint, mutual coupling, quantisation, and calibration drift. A cross-layer scheduler enforces an explicit ADC bit-budget per frame while meeting safety-critical latency and reliability targets, and it reuses RSU beacons for bistatic sensing and congestion-aware allocations at intersections. We evaluate the full stack in an urban four-way intersection scenario using simulation with hardware-calibrated impairment models. Relative to an 8-bit full-rate vehicle-only baseline, the RSU-assisted 3-bit low-rate configuration achieves 58% ADC-bit savings while maintaining 0.21 m range RMSE and 6.98 ms 99th-percentile one-way latency under the URLLC constraint set. These results indicate a practical path to reduce cost and power while preserving perception quality and V2X service in RSU-covered urban areas.