Analysis of Coverage Efficiency of Radio-over-Fiber Network for Railway LOCOTROL Wireless Communication System

Radio-over-fiber (RoF) technology can effectively improve reliability and quality of service (QoS) of railway communication systems. This paper studies the coverage efficiency of ROF in heavy haul railway. Coverage efficiency is determined by calculating the area power consumption of cell according to combined path loss and shadowing model. The value of the length of remote antenna unit (RAU) cells overlapping area, which would maximize coverage efficiency in different situations, is also estimated. Then, the relation between coverage efficiency and the proportion of antennas installed on the roof of train and RAUs is analyzed. Through theoretical analysis and experimental results, a conclusion for heavy-haul railway can be acquired. When the users' minimum power requirement is fixed, the proportion of train antennas and RAUs which would maximize coverage efficiency is only decided by the separation distance of train antennas rather than the number of them. Meanwhile, the optimal proportions of train antennas and RAUs for corresponding interval of separation distance of train antennas and different users' minimum power requirement are provided.