智能交通系统中的车对车宽带无线信道建模

发布时间：2018-04-26 06:45

本文选题：车对车通信 + 汽车对汽车通信　；参考：《北京交通大学》2014年博士论文

【摘要】：随着人们生活节奏的不断加快和路面运行车辆的爆发式增长,公路交通拥堵和公路、铁路交通事故频发成为困扰整个社会的难题。智能交通系统中的车载互联网能够将公路交通中的汽车和高速铁路中的列车分别连接起来,使每辆车维持一个一定范围内的车辆运动状态数据库,以预防碰撞事故发生。同时,车载互联网还能有效调度公路车辆运行,为车辆提供合理且最优的运行路线,以缓解部分地区的拥堵局面。可以说,车载互联网为现代交通运输智能化管理提供了解决方案,而这一切有赖于一个切实有效的车载无线通信系统。众所周知,无线信道建模工作是无线系统设计的重中之重。因此,我们必须广泛而深入地开展车对车无线信道建模工作。本文整体研究思路是将车对车通信细分为汽车对汽车通信和高速铁路列车对列车通信两个分支。首先结合车对车通信所独具的高速移动、高多普勒频移和低天线高度等特点,建立了车对车宽带无线信道建模理论和方法。研究了大尺度路径损耗和阴影衰落,小尺度均方根时延扩展、多径延迟线模型、多径莱斯K因子和多径包络相关性等宽带无线信道建模指标。改进了无线信道冲激响应表达式,以突显车对车通信中的多径生灭特性。提出了适于车对车无线信道建模的统计概率分布,以反映多径包络的小尺度快速时变特性。同时,阐释了改进的非几何统计和二维几何统计两种建模方法在车对车无线信道建模中的深刻内涵和内在联系。通过为模型中的发射机、接收机、静态散射体和漫散射体赋予高度维度,本文首次将基于计算机仿真的汽车对汽车非几何统计性建模方法从二维空间拓展至三维空间。其次,在汽车对汽车无线信道建模方面,本文以无线电波传播环境为驱动,划分了汽车对汽车无线传播场景,建立了汽车对汽车无线传播场景四级架构。以此为基础,遴选车辆视距传播、车辆部分视距传播(斜坡和立交桥)、车辆非视距传播和车辆停车场环境等四大典型汽车对汽车无线通信传播环境,采用改进的非几何统计性建模方法,首次在这些场景中从大尺度路径损耗,小尺度均方根时延扩展、多径延迟线模型、多径莱斯K因子、多径相关性和多径生灭性等宽带无线信道建模指标出发,提出对应的宽带无线信道模型,以探求视距出现程度对汽车对汽车无线信道特征的影响。同时,搭建部分视距场景中斜坡和立交桥环境无线传播信道仿真平台以验证实测信道模型的准确性。首次将绕射损耗计算引入汽车对汽车几何统计仿真平台中,从高度维度入手建立由桥体和坡体遮挡引起的阴影衰落损耗模型,从而扩大了非几何统计性建模方法的可用范围。最后,对于高速列车对列车无线信道建模,本文划分了高速铁路列车对列车无线传播场景。为解决同轨列车在间隔10Km情况下的直接通信问题,搭建了基于邻轨列车中继多跳协作的高速铁路列车对列车物理层无线通信模型,推导了该无线通信模型的误码率和中断概率解析表达式。发现了高速铁路城区高架桥周边分布散射体的二元属性,阐释了城区高架桥场景波导效应成因,并由此出发采用三维几何统计性建模方法,搭建了城区高架桥场景下列车对列车宽带无线信道仿真平台。研究了高速列车对列车无线信道大尺度路径损耗,小尺度均方根时延扩展、莱斯K因子、多径延迟线模型等宽带无线信道特征。
[Abstract]:With the continuous acceleration of people's life rhythm and the explosive growth of vehicles running on the road, traffic congestion and highways and railway traffic accidents have become a difficult problem for the whole society. The vehicle Internet in the intelligent transportation system can connect the cars in the highway traffic with the trains in the high-speed railway, so that each vehicle can be maintained. At the same time, the vehicle Internet can effectively control the operation of the road vehicles and provide a reasonable and optimal operation route for the vehicles to relieve the congestion in some areas. All this depends on a practical and effective vehicle wireless communication system. It is well known that wireless channel modeling is the most important design of the wireless system. Therefore, we must develop the vehicle wireless channel modeling work extensively and deeply.
The whole research idea of this paper is to subdivide the car to car communication into two branches of automobile communication and high speed railway train to train communication. Firstly, the theory and method of modeling and method of vehicle to car broadband non line channel modeling are established by combining the characteristics of high speed movement, high Doppler shift and low antenna height. Path loss and shadow fading, small scale mean square root delay extension, multipath delay line model, multipath K factor and multipath envelope correlation, improve the expression of impulse response in wireless channel to highlight the multipath characteristics in vehicle communication, and propose a model suitable for vehicle wireless channel modeling. The probability distribution is calculated to reflect the small scale fast time-varying characteristics of the multipath envelope. At the same time, the profound connotation and internal relations of the improved two modeling methods of non geometric statistics and two-dimensional geometric statistics in car to car wireless channel modeling are explained. The high dimension of the model is given by the transmitter, receiver, static scatterer and diffuse body in the model. For the first time, this paper extends the non geometric statistical modeling method of automobile based on computer simulation from two dimensions to three dimensions.
Secondly, in the automobile wireless channel modeling, this paper divides the vehicle wireless transmission scene with the wireless wave propagation environment, and establishes the four level architecture of the vehicle wireless transmission scene. Based on this, it selects the vehicle sight distance transmission, the vehicle division distance transmission (slope and overpass), and the vehicle non sight distance propagation. For the first time, the improved non geometric statistical modeling method is used for the four typical vehicles of vehicle parking environment, such as the environment of the vehicle wireless communication. In these scenes, the large scale path loss, the small scale root mean square root delay extension, the multipath delay line model, the multipath K dependent son, the multipath correlation and the multipath inefficiency are used for the first time in these scenes. On the basis of channel modeling, a corresponding broadband wireless channel model is proposed to explore the influence of the degree of sight distance on the vehicle's wireless channel characteristics. At the same time, the accuracy of the simulation platform of the measured channel model is verified by building a simulation platform of the slope and the flyover environment wireless communication channel in some sight distance scenes. In the vehicle geometric statistical simulation platform, the shadow fading loss model caused by the bridge body and the slope body occlusion is established from the height dimension, thus the available scope of the non geometric statistical modeling method is expanded.
Finally, for high-speed train to train wireless channel modeling, this paper divides the high-speed railway train to train radio transmission scene. In order to solve the direct communication problem of the same rail train at the interval of 10Km, a wireless communication model of the train physical layer on the high speed railway train based on the multi hop cooperation of the adjacent rail train relay is built. The error rate of the line communication model and the analytic expression of the interruption probability are expressed. The two element attributes of the scattered scatterers around the viaduct around the high speed railway are discovered, and the cause of the scene waveguide effect of the urban viaduct is explained, and a three-dimensional geometric statistical modeling method is used to build a broadband wireless letter to the train under the urban viaduct scene. The channel simulation platform is used to study the broadband wireless channel characteristics of the high speed train, such as the large scale path loss of the train wireless channel, the small scale root mean square root delay extension, the lace K factor, the multipath delay line model and so on.

【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.5

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