Modeling of Millimeter-Wave Propagation in Tunnels with Split-Step Parabolic Equation Method

Abstract

Radio wave propagation modeling in tunnels plays an important role in the deployment of modern train communication systems. The parabolic equation method has proven to be a powerful numerical technique for propagation modeling in long guiding structures. However, its computational efficiency is significantly compromised at millimeter-wave frequencies. This paper presents a split-step Fourier transform based parabolic equation model, which can achieve superior performance at the millimeter-wave bands. Numerical results are validated against analytical solutions in a waveguide example, as well as experimental measurements in an actual tunnel.