“智能”汽车或智能车辆的概念被认为是降低当今世界道路上高死亡率的最有希望的解决方案之一。此外，最近发布的标准如欧洲智能交通系统（ITS）或国际标准IEEE 802.11p，证实了未来车对车或车对基础设施网络的重要性，例如，它可以减少交通堵塞或帮助驾驶员了解道路状况或天气预报，以防止事故发生。这种智能网络在事故预防方面的主要缺点在于道路上存在障碍物或不采用V2V系统的汽车。因此，基于用V2V通信波形的雷达应用可以作为避免碰撞的直接方法。
本论文的目的在于验证一种雷达应用在V2V场景中的可行性。因此，对已实现的V2V传播信道进行了全面评估，以确定可能影响检测和定位应用的主要约束因素，例如功率衰落、非广域平稳不相关散射（NWSSUS）或多普勒频率。
基于V2V信道特性的结论，设计了雷达算法和跟踪系统。该雷达算法的设计基于功率峰值检测，基于可能目标产生的反射功率来估计信道冲激响应。三边测量法用于定位这些目标在方位平面上的位置，因此需要一个多输入多输出系统。为了进行这一可行性研究，我们模拟了一个4x4 MIMO结构，该结构使用PSK或QAM作为调制方式，并在实际的V2V传输信道上进行了仿真。
考虑了几何随机信道模型（GSCM），因为它包含了大多数相关信道特性，特别是模拟了这类信道的典型非广义平稳不相关散射（NWSSUS）行为。此外，还实现了IEEE 802.11p标准，以模拟尽可能接近实际的场景。所获得的结果对实施情景得出了积极的结论。需要强调的是，将该算法外推到其他环境中会导致检测概率的提高或降低。
然而，本论文最有价值的部分是在V2V场景下雷达实现的结论。论文共分为五章。第一章为绪论，第二章为V2V实现系统，第三章为V2V传播信道的特性描述，第四章为雷达和跟踪系统，第五章为提出的雷达算法的结果。最后，对本文的结论和未来工作进行了详细的总结。
The concept of “smart” cars or intelligent vehicles is presented as one of the most promising solutions to reduce the high mortality rate that occurs on the world’s roads nowadays. Besides, the recent publication of standards as the European Standard for Intelligent Transportation System (ITS) or the international standard IEEE 802.11p confirm the importance of the future vehicle-to-vehicle or vehicle-to-infrastructure networks, which can diminish gridlocks or aid the driver with information about the road status or the weather forecast in order to prevent accidents, for instance. The main drawbacks of such intelligent network regarding the accident prevention lie in the presence of obstructing objects on the road or cars that do not implement this V2V system. Therefore, a radar application based on the used waveform for the V2V communication can be suitable as a direct method to avoid collisions. The aim of this thesis consists in the verification of the viability of a radar application in a V2V scenario. Thus, a thorough evaluation of the implemented V2V propagation channel has been performed so as to determine the main constraint factors, such as the power fading, Non Wide Sense Stationary Uncorrelated Scattering (NWSSUS) or the Doppler frequency, that can affect at detection and location application. From the conclusions obtained based on the characterization of a V2V channel, a radar algorithm has been designed as well as a tracking system. The design of the proposed radar algorithm is based on power peak detection that the estimated channel impulse response presents based on the reflected power originated by possible targets. The trilateration method is used for the location of these targets in the azimuth plane; thus, a Multiple Input Multiple Output system is required. In order to carry out this viability study, a MIMO structure 4x4 using OFDM with PSK or QAM as the modulation and over a real V2V propagation channel has been simulated. The Geometric Stochastic Channel Model (GSCM) is considered, since it contains most of the relevant channel-specific features; in particular it models the Non Wide Sense Stationary Uncorrelated Scattering (NWSSUS) behavior typical for such channels. Furthermore, the IEEE 802.11p standard has been implemented so as to simulate a scenario as close to reality as possible. The results obtained conclude with a positive result for the implemented scenarios. It is important to highlight that the extrapolation of this algorithm to other environments can lead to improvements or deteriorations of the probability of detection. However, the most valuable part of the thesis is the conclusion obtained for a radar implementation in a V2V scenario. The thesis is organized into 5 chapters. The first chapter provides an introduction, the second chapter explains the V2V implemented system, the third chapter contains the characterization of the V2V propagation channel, the forth chapter explains the radar and tracking system, while the fifth chapter presents the results of the proposed radar algorithm. Furthermore, at the end of the thesis some conclusions and future work are detailed.
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引言
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场景描述
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V2V传播信道
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V2V环境中的雷达系统
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结果
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