A Study of Interference on Underground Tunnel in Radio Frequency-Communication Based Train Control System

무선 통신기반 열차제어시스템의 지하구간 전파간섭에 대한 연구

In the system necessary for safety such as the train control system, to make train control information be sent correctly is very important. In the case of the system such as RF-CBTC(Radio Frequency-Communication Based Train Control), sometimes failure in correctness of train controlling information may happen because the information is sent throughout wireless transmission between on-board system of a train and wayside transmitter, and then, it is exposed to noises. Of RF-channel interference, there are various forms. Under the environment of mobile telecommunications, adjacent-channel interference and Co-channel interference are in trouble, and under the environment of the wireless LAN, inter-symbol interference is in trouble. Also, the system of the cellular CDMA mobile telecommunication is affected on the RF-channel interference such as Doppler effect, multi-cell interference, and other users' intervention. In this paper, we analyzed the effect of the train control information related to fading, intervention and other noises made in the underground interval and explained the transmission characteristics numerically. Furthermore, we calculated the mean of the error terms by increasing users in the system of the cellular CDMA. As the method for decrease the error term of sent information, we represented the way adjusting the arrangement of antennas, and we did the model related to the system of RF-CBTC in which the location of an antenna is calculated with really measured value of the transmission characteristics and the way confirming reliability of the wireless transmission.