FSO communication system for high-speed trains under varying visibility conditions

Hasan Abbas Al-Mohammed, Muhammed Al-Ali, Elias Yaacoub

不同能见度条件下的高速列车自由空间光学(FSO)通信系统"

哈桑·阿巴斯·穆罕默德，穆罕默德·阿里，伊莱亚斯·雅库布

Abstract: High-speed train systems are rapidly growing in complexity and coverage, demanding efficient high-speed internet services. Existing radio frequency technology struggles to meet these demands due to handover mechanisms and limited connectivity times. Furthermore, current free-space optics (FSO) techniques require a large number of base stations (BSs), resulting in high costs. This study presents a novel high-speed train communication technique, using FSO, that significantly reduces the number of required BSs while maintaining sufficient coverage and data speeds. The proposed technique can be adapted for fixed or variable representations of transmitted and received power, providing a fixed or variable data rate. The research also investigates the impact of divergence angle on transmitted and received power. By employing the proposed communication technique, a system with a fixed data rate, such as 1.25 Gbps, can be achieved. The results demonstrate the potential of this approach in high-speed train applications, reducing the number of BSs from 113, as reported in the best existing literature, to less than 10. Weather conditions, including clear, haze, thin fog, light fog, and heavy fog, are considered when calculating the required BS locations to achieve a target data rate. Additionally, this work introduces a new handover mechanism and mathematical formulation, providing a more comprehensive solution for high-speed train communication systems. The simulations and evaluations conducted in this study are based on parameters and equations from previous works to ensure a fair comparison.

Keywords: Free space optics (FSO); High-speed train; Acquisition-tracking-pointing (ATP); Optimization Handover wireless optical communication

摘要：随着高速列车系统的迅速发展，其体系愈加复杂，覆盖范围不断增大，这一发展迫切需要相应的高速网络服务与其进行对接。但是由于切换机制和连接时间有限，现有的射频技术难以满足这些需求。与此同时，当前的自由空间光学通信(FSO)技术的应用需要以大量的基站(BSs)为物理支撑，这使得其运行成本十分高昂。本研究提出了一种新型高速列车通信技术，其通过应用自由空间光学通信(FSO)进行高速数据传输，可以显著减少所需的基站（BSs）数量，但同时又能够保持充足的覆盖范围和数据传输速度。此外，这项提出的新型高速列车通信技术还可以适应无线电通信中的功率控制技术，从而提供固定或可变发射功率和数据速率。与此同时，本研究还调查了发散角对发射和接收功率的影响。在调查过程中，通过采用所提出的新型高速列车通信技术，系统中的数据速率(例如1.25 Gbps)能够保持恒定。结果表明，该技术在高速列车应用中潜力巨大，它可以显著减少所需的基站数量：从现有权威文献报道的113个减少到不到10个。为了达到目标数据速率，在计算所需的基站位置时，需要考虑各种天气条件，包括晴天、雾、薄雾、轻雾和浓雾。最后，本研究还引入了一个新的切换机制和数学公式，为高速列车通信系统提供了一个更加综合、全面和系统的解决方案。此外，本研究中进行的模拟和评估均以往研究的参数和方程为基础，以确保比较的准确性和客观性。

关键词：自由空间光学通信(FSO)；高速列车；采集跟踪指向(ATP);优化无线光通信切换

来源：Vehicular Communications

发表时间：2023年7月20日

检索：罗阳

翻译：谢鑫飞

一审：黄辉

二审：彭莉

三审：罗玲娟

上传发布：姜浩