车车通信时变多普勒概率密度分析

Analysis of Delay-Dependent Doppler Probability Density Functions for Vehicle-to-Vehicle Communication

多普勒谱的研究一直以来都是车车(V2V)通信信道建模中一个重要的研究方向。文章基于几何单反椭圆模型(GBSBEM)、二维街道模型对T字路口车车通信信道的时变多普勒频移进行了分析。首先利用GBSBEM模型得出对应的时延椭圆上各点的极坐标表达式和椭圆上散射点满足的概率密度函数,然后将多普勒频移与椭圆上每个点的坐标建立函数关系,最后通过随机过程的相关知识推导出在此场景下以及有阻挡物体存在的情形下车车信道的时变多普勒概率密度函数,并给出仿真结果。

The research about Doppler spectrum plays an important role in the study of vehicle-to-vehicle(V2 V)channel modeling.In this paper,the time-varying Doppler shift of the T-junction vehicle-to-vehicle channel is analyzed based on the geometrically based single bounce elliptical model and the two-dimensional street model.Firstly,using the theory of GBSBEM,the expression of each point on the corresponding time-delay ellipse and the probability density function of the scattering points on the ellipse are obtained.Then the Doppler shift is functionally related to the coordinates of each point on the corresponding ellipse.Finally,the time-varying Doppler probability density function of V2 Vchannel in this scenario is derived using the knowledge of stochastic process,and the simulation results are displayed.The scenario with blocking objects is derived by the above method.