Fusion-Aware Beam Tracking for Robust High-Mobility RF-FSO Communication

This paper proposes a radio frequency-free space optics (RF-FSO) fusion beam tracking algorithm for highmobility hybrid RF-FSO communication. By combining the widebeam dynamic control of millimeter-wave (mmWave) phased array RF system and the precise laser tracking of acquisition, tracking, and pointing (ATP) FSO system, a Kalman filter-based fusion algorithm is developed. Simulation results show that the algorithm enables 86.98 % faster initial acquisition via mmWave adaptive beam narrowing compared to a single FSO system and improves angular tracking accuracy by about 75 % with laser activation. The RF-FSO fusion system achieves mutual gains in its respective single systems, providing robust support for high-mobility scenarios and improving communication capacity through signal-to-noise ratio (SNR) enhancements enabled by improved alignment accuracy. The proposed algorithmic mechanism effectively demonstrates the effectiveness of RF-FSO fusion beam tracking in high-mobility scenarios.