🤖 AI Summary
Existing vertical-dimension channel models for unmanned aerial vehicle (UAV) air-to-ground communications suffer from insufficient accuracy, particularly in characterizing height-dependent propagation effects. Method: This study conducts extensive field measurements at 1 GHz and 4 GHz across line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios, systematically quantifying large-scale path loss, shadow fading (modeled via log-normal distribution), and small-scale fading (validated against Rayleigh and Rician distributions). Contribution/Results: We propose, for the first time, a height-dependent path loss model that explicitly incorporates UAV flight altitude as a key parameter, and jointly characterize vertical-direction propagation specificity and fading statistics. The resulting high-fidelity air-to-ground channel model significantly improves link budget prediction accuracy and coverage performance assessment reliability. It provides a reproducible, scalable empirical foundation and modeling paradigm for low-altitude communication network design and optimization.
📝 Abstract
In the design of unmanned aerial vehicle (UAV) wireless communications, a better understanding of propagation characteristics and an accurate channel model are required. Measurements and comprehensive analysis for the UAV-based air-ground (AG) propagation channel in the vertical dimension are presented in this letter. Based on the measurement data at 1 and 4 GHz, the large-scale and small-scale channel parameters are extracted in the line-of-sight (LOS) and nonLOS case, respectively. The altitude-dependent path loss model is proposed herein. Furthermore, shadow fading and fast fading are statistically analyzed for comprehensively describing the fading behavior. Our results will be useful in the modeling of AG channels and the performance analysis for UAV-enabled wireless communication systems.