Summary
International Symposium on Antennas and Propagation
2010
Session Number:3TE4
Session:
Number:3TE4-1
Calculation of the Field Distribution in a Railway Tunnel in Presence of Train Using Integrative Modelling Technique
Shi Pu, Jun-Hong Wang, Yu-Jian Li,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
Within confined or semi-confined areas, the influence of environment on the propagation of radio waves is very significant, especially for the discrete antenna system. Commonly, radio wave coverage inside the tunnel for train-to-wayside communication is achieved using leaky coaxial cable (LCX), so it is important to know the property of the wireless radio wave link involving the LCX. Therefore, it is necessary to develop efficient method that can be used to model the whole wireless radio link based on LCX accurately. This is the motivation of this paper. The method in this paper can be divided into three parts (take downlink as example) [1, 2]: The radiating of radio frequency (RF) signal by LCX, the propagating of the wave in tunnel in presence of train, and the receiving of the RF signal by train antennas. In fact, many efforts have been made in studying the tunnel and indoor propagation relative issues. However, the majority of these works are focused on the second part of the RF link as mentioned above, without considering the transmitting/receiving (Tx/Rx) components [3], or just simply considering the wave propagation as that in a relatively large hollow waveguide [4]. Regarding the LCX, some works about radio coverage prediction of radiating-mode LCX have been reported [5, 6]. These works could be applied to the cases of relatively empty tunnel or indoor scenarios, where the radiating wave of LCX can be treated as plane waves, so that the ray-tracing method can be used. However, for the complicated environment such as tunnel in presence of train, the ray-tracing based solutions are not accurate enough. In this paper, the FDTD method is employed to take into account not only the multi-path reflecting, scattering, diffracting, etc., but also the effects of Tx/Rx antennas.