Researches And Applications Of Millimeter Wave Wireless Channel Characteristics In Rail Traffic Station Scenarios

At present,rail traffic is developing towards intelligence.The ultra-high-speed,highreliability,and low-latency wireless communication is the key to realizing smart rail traffic.Therefore,as the basis of wireless communication in rail traffic scenarios,the characteristics of wireless channel are the focus of current research.This paper focuses on the important scenario of rail traffic such as stations.Based on ray tracing technology,the characteristics of millimeter-wave wireless channel are analyzed,and the wireless channel model is investigated.The human model is established to study the influence mechanism of human body on wireless channels.Then,the paper proposes the network optimization deployment plan in the station,and analyzes the wireless channel characteristics affected by passenger flow,which provide support for 5G network deployment in rail traffic station scenarios.The main work and innovations of this paper are as follows:(1)For the three types of subway stations,including side,island and hybrid platform,with the 3D scenario models,wireless channel characteristics are investigated,channel models including path loss,multipath delay,and spatial angle spectrum are established,and network optimization deployment applications are proposed,such as antenna position,antenna array,antenna element spacing,arrangement direction,etc.(2)For the impact of the human body on the wireless channel at the millimeter wave frequency band,the human body is divided into four parts: torso,head,arms and legs.It is found that human body modeling as a combinatorial optimization is the NP-hard problem.Based on the greedy algorithm,a 3D human body modeling method with higher accuracy and lower complexity is proposed,then the influence mechanism of the static/dynamic human body on the wireless channel is explored.(3)For the wireless channel considering the human body effects in the station,based on the human body model and pedestrian traffic flow model,the passenger distribution model is established.Then,the paper analyzes the stationary/non-stationary properties of wireless channel affected by factors such as passenger flow,passenger flow density,and passenger flow speed,and proposes the network optimization deployment scheme in the station scenario.The achievement of this paper can provide reference for the research of wireless transmission technologies and network deployment of public and private networks in rail traffic station scenarios.