Multi-Frequency Channel Measurements and Characterization for In-Cabin Environments

This letter presents a preliminary statistical characterization of the in-cabin channel at multiple frequencies. Narrowband measurements are launched inside a medium-size and range Airbus A321-200 aircraft for frequencies between 3.5 and 60 GHz. According to the results Alpha Beta Gamma (ABG) model predicts the multi-frequency path loss with substantial efficacy against other examined empirical models. The shadow fading increases progressively with frequency with a standard deviation from 1.9 up to 3.0 dB. The small-scale fading exhibits Rayleigh characteristics with negative K-factors at lower frequencies (3.5 and 8 GHz), which gradually increase and become positive at higher frequencies (14 and 60 GHz), indicating a Rician fading channel. The spatial correlation of the channel is modeled using an exponentially decaying sinusoidal pattern, with decorrelation occurring more rapidly at higher frequencies. Finally, the channel is found to be favorable for the application of frequency diversity.