Radio Wave Propagation Characteristics of Special Communication Channel for High-Speed Railway

The frequency response of radio wave propagation of special communication channel for high-speed railway in high-speed train coach was calculated according to ray tracing method and tent law.From the calculation,we know that the path loss of radio wave propagation in train coach is greater than 30 dB.The frequency response of radio wave propagation in train coach was measured,and the measured data were processed by Inverse Fast Fourier Transform(IFFT).It's known that the average power delay profile(PDP) of radio wave propagation accords with Saleh-Valenzuela(SV) model under the conditions of line-of-sight(LOS) and non-line-of-sight(NLOS).Power function is more suitable to describe the relationship between RMS delay spread and propagation distance.The measured data were further treated statistically to obtain the key parameters of SV model as well as the small-scale fading model and path loss model of radio wave propagation in train coach.The small-scale fading of radio wave propagation in train coach obeys log-normal distribution under LOS condition and Rayleigh distribution under NLOS condition.The environmental index of radio wave propagation in train coach is 1.283 under LOS condition and 1.098 under NLOS condition.