Research on field-to-circuit signal characteristics of train antennas in railway communication environment using integrative modeling technique

In modern railway wireless communications, the transmission properties of information between train and wayside would be affected by the complicated environment. In this paper, an integrative modeling technique (IMT) which involves finite-difference time-domain (FDTD) method with uni-axial anisotropic perfectly matched layer (UPML) technique is applied to study the field-to-circuit characteristics of train antennas with complex railway environment considered, such as the locomotive body, overhead contact line for power supply, locomotive pantograph, steel rails, ballastless track, earth plane, etc.. Besides, the spark-over between the pantograph and overhead line is simulated and introduced into the integrated computation model as an electromagnetic noise, which is excited frequently with the moving of high-speed train. By adding BPSK modulator-demodulator into the integrative computation model, the results show that the influence of the electrified railway environment and the spark-over noise on quality of RF signal transmission is very significant and it will probably cause the increase of bit error probability.