マイクロ波による鉄道通信システムにおける伝搬特性

Abstract

Recently, the utilization of radio equipments along railways have been advanced rapidly in Japan. The importance of these radio systems rise in train control, information services and other communication systems. But the current frequency band width in UHF band assigned to Japanese railway companies is narrow to satisfy future various requirements for railway works and customer services. In this paper, we first present a construction of a next generation radio communication system using the microwave band radio between running trains and ground radio base station, as the system which can cope with the increase of the communication traffic volume in the railway communication. Secondly, we study the propagation characteristics on radio links to introduce this communication system into actual conventional lines. Concretely, we consider that the typical railway environments are distinguished to several types on analyses by complication of environments along a railway track. For each type, we calculate the propagation characteristics on a proper model. Also, we examine influences of rain which have an important effect on circuit quality. Computer simulation indicates that these analyses are effective to rationalize this communication system using the microwave band radio.