Analysis of Frequency-Dependent Line-of-Sight Probability in 3-D Environment

Since mmWave signals are sensitive to blockages, prior channel models including the LoS probability function for ultra-high frequency band cannot be applied directly to analyze mmWave cellular networks. Compared with the empirical LoS probability model obtained from the computationally intensive simulations and measurements, the theoretical LoS probability model in mmWave cellular networks still remains unclear. According to the Huygens-Fresnel principle for the wave propagation, the LoS probability is closely related to the carrier frequency. In this letter, the 3-D frequency-dependent LoS probability model incorporated with the Fresnel zone is presented, and shows good agreement with the empirical models adopted in the 3GPP standard for various scenarios.