车联网连通性的关键技术研究

发布时间：2018-04-13 01:16

本文选题：车载自组织网络 + 多跳通信　；参考：《北京交通大学》2017年硕士论文

【摘要】：随着中国工业化进程的不断加速,国民生活水平的提高,汽车出行成为一种普遍的出行方式,但是由此引发的道路拥堵、交通安全、环境污染等问题日益严重,这也成为现代交通领域研究的热点。为缓解城市道路拥堵问题,提高出行效率以及资源利用率,我国开始了智能交通系统(Intelligent Traffic System,ITS)的研究。车载自组织网络是实现智能交通的不可或缺的一部分,ITS中各种信息的传输可以通过车载自组织网络来进行,因此对车载自组织网络进行研究十分必要。在车载自组织网络中通常用连通性来描述通信质量,实际应用场景中网络之间通信链路的建立并不能够达到100%。本人通过对车载自组织网络车车通信、车路通信研究现状的学习及相关文献的查阅,从多个方面对车载自组织网络中的连通性进行研究,主要研究内容及创新点如下:第一,对高速公路场景下基于空间依赖性的多跳车车通信进行建模分析,为车联网实际场景下车车通信系统的设计以及性能评估提供了有效途径。本文分别在单车道和双车道高速公路模型下对车车通信中的多跳连通概率进行研究,单车道模型下,考虑车辆的密度、车辆分布、车间最小安全距离以及车辆单跳通信半径等因素,在Unit-disk模型和对数正态阴影衰落模型下对多跳连通概率进行分析;双车道模型下,针对车辆空间依赖性问题进行分析,提出一种基于相交面积的车车多跳通信模型。仿真结果表明,该分析模型更加符合实际车车通信场景,车辆之间通信的连通概率与信道环境、车间距离、车辆密度等因素都有一定的关系。第二,车路通信也是车载自组织网络通信中的一个重要通信方式。本研究针对基站之间部署距离远,车路通信效果不佳的问题提出一种基于车车通信辅助的车路通信模型。首先考虑了高速公路上存在不同类型的车辆,对提出的合作通信模型进行深入分析,然后根据基站之间的距离分五种情形分别推导了提出模型的连接概率的通用理论表达式,最后给出了详细的仿真对比研究结果。第三,在车联网通信场景中,车辆分簇是一种聚集方式。本研究分别从前传过程和追赶过程两个方面对车车通信的连通性进行研究。前传过程主要研究簇内车辆的多跳通信,追赶过程主要对簇间车辆的通信进行分析。仿真表明前传过程中簇的大小对于车车通信连通概率的影响较大,而追赶过程部分的研究表明车辆之间的初始距离与超车成功的概率有一定的关系,该模型下的车联网连通概率研究对于评价车辆的移动行为提供了一定的理论依据。
[Abstract]:With the acceleration of China's industrialization process and the improvement of people's living standards, automobile travel has become a common travel mode, but the resulting road congestion, traffic safety, environmental pollution and other problems have become increasingly serious.This has also become a hot spot in the field of modern transportation.In order to alleviate the problem of urban road congestion, improve travel efficiency and resource utilization, the research of Intelligent Traffic system (its) has been started in China.Vehicle ad hoc network is an indispensable part of intelligent transportation. The transmission of all kinds of information in its can be carried out through the vehicle ad hoc network, so it is very necessary to study the vehicle ad hoc network.Connectivity is usually used to describe communication quality in vehicle-borne ad hoc networks. In practical application scenarios, the establishment of communication links between networks can not reach 100%.By studying the status quo of vehicle-vehicle communication and vehicle-road communication and consulting related literature, I study the connectivity of vehicle-borne ad hoc network from many aspects. The main research contents and innovations are as follows: first,The modeling and analysis of multi-hop vehicle communication based on spatial dependence in freeway scene provides an effective way for the design and performance evaluation of vehicle communication system in the actual scene of vehicle networking.In this paper, the multi-hop connectivity probability in vehicle-vehicle communication is studied under the single-lane and two-lane freeway models respectively. Under the single-lane model, the density and distribution of vehicles are considered.Under the Unit-disk model and logarithmic normal shadow fading model, the multi-hop connectivity probability is analyzed under the minimum safety distance of workshop and the vehicle one-hop communication radius, and the spatial dependence of vehicle is analyzed under the two-lane model.A vehicle multi-hop communication model based on intersection area is proposed.The simulation results show that the analysis model is more consistent with the actual vehicle-vehicle communication scenario, and the connectivity probability of the vehicle communication is related to the channel environment, workshop distance, vehicle density and other factors.Secondly, vehicle-road communication is also an important communication mode in vehicle-borne ad hoc network communication.In this paper, a vehicle-road communication model based on vehicle-vehicle communication assistance is proposed to solve the problem of long deployment distance between base stations and poor effect of vehicle-road communication.Firstly, considering the existence of different types of vehicles on the freeway, the proposed cooperative communication model is deeply analyzed, and then the general theoretical expression of the connection probability of the proposed model is derived according to the five cases of distance between base stations.Finally, the detailed simulation results are given.Thirdly, vehicle clustering is a kind of clustering method in the vehicle networking communication scene.In this study, the connectivity of vehicle-vehicle communication is studied from two aspects: the prepassing process and the catch-up process.The prepassing process mainly studies the multi-hop communication of the vehicles in the cluster, and the chase process mainly analyzes the communication between the vehicles in the cluster.Simulation results show that the size of the cluster has a great influence on the communication connectivity probability of vehicle and vehicle, while the study of the catch-up process shows that the initial distance between vehicles and the probability of overtaking is related to the probability of overtaking.The research on the connectivity probability of vehicle network under this model provides a theoretical basis for evaluating the mobile behavior of vehicles.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5;U495

【参考文献】