非稳态三维散射场景的时域自相关特性分析

摘要

The expression of the temporal autocorrelation function for the three dimensional (3D) and non-stationary aeronautical scattering environment is derived, where the scatters are in random motion relative to transceivers. The expression involves high dimensional integration with finite interval, thus a ray-tracing based model is proposed to verify its validity. Numerical results show that as the increase of the velocity of transceivers or the velocity and density of the scatters increases, the temporal autocorrelation function would attenuate more rapidly. The deduced expression and the proposed ray-tracing based model can be extended to other scenarios. Both the two dimensional (2D) multipath scattering and the stationary multipath scattering are two special cases. These results allow engineers more appropriate determination on the coherence time and coherence bandwidth for the future broadband aeronautical mobile communication.%结合航空移动通信环境的三维非稳态特征，推导了立体空域内散射体相对于收发节点随机运动散射场景的时域自相关函数的数学表达式。该表达式为有限区间内的高维积分，结合蒙特卡洛高维积分法和射线跟踪法验证了该表达式的正确性。数值结果表明：节点运动速度、散射体速度和散射体数量越大，相应的时域自相关函数衰减越快。该表达式和求解办法具有较强的推广性，通过降维可等效为二维散射场景，令散射体相对于收发节点静止可等效为稳态散射场景。相关结论可为下一代航空移动通信宽带传输体制的相干时间与相干距离的确定提供理论支撑。