V2V三维宽带信道建模与统计特性分析

针对5G车对车(vehicle to vehicle, V2V)无线通信系统，基于几何随机建模方法，提出一种改进的三维宽带多输入多输出(multiple-input and multiple-outpit, MIMO)信道模型。引入多共焦半椭球体模型用于研究不同传播延迟下的V2V信道统计特性，结合时变的路径长度、信号角度和莱斯因子表征V2V信道的非平稳特性。推导了空-时相关函数、多普勒功率谱密度等关键信道统计特性的数学表达式。分析了城市和高速场景下信道相关特性的差别，并研究了车流密度、运动方向、天线角度、传播延迟等因素对信道统计特性的影响。结果表明，城市场景下的时间相关性和空间相关性明显低于高速场景；不同传播延迟下的V2V信道统计特性有明显差异；信道相关性同天线阵列角度、收发车运动方向和时间变化密切相关。模型仿真结果为车载通信提供了一些有价值的结论，可以作为未来V2V通信系统设计、优化和评估的有效指导。仿真结果与实测数据较好地吻合，证明模型能正确表征V2V无线信道的相关特性。

3D wideband channel modeling and statistical characteristic analysis for V2V communication

An improved 3D geometry-based stochastic wideband MIMO geometric stochastic model is proposed for 5G vehicle-to-vehicle (V2V) channel. The multi-confocal semi-ellipsoid model is introduced to study the statistical characteristics of V2V channel under different propagation delays, and the non-stationary characteristics of the channel are characterized by the time-varying path length, signal angle and Rician factor. Formulas for key channel statistical characteristics such as spatial-temporal correlation function and Doppler power spectral density are derived. The differences of channel correlation characteristics between urban and highway scenarios are analyzed, and the influences of traffic density, motion direction, antenna angle, propagation delay and other factors on channel statistical characteristics are studied. The results show that the temporal correlation and spatial correlation in urban scenarios are significantly lower than those in highway scenarios. The statistical characteristics of V2V channel under different propagation delays are obviously different. The channel correlation is closely related to the antenna array angle, the movement direction of the transceiver and the time variation. The results provide some valuable conclusions for vehicle communication, and can be used as effective guidance for the design, optimization, and evaluation of future V2V communication systems. Simulation results are in good agreement with the measured data, proving that the model can correctly represent the characteristics of V2V wireless channel.