中文摘要：

基于麦克斯韦（Maxwell）方程的蒙特卡洛数值模拟,计算出城市建筑物介质粗糙面模型中信号的幅度分布和相位分布,分析信号在空间尺度上诸如快衰落、慢衰落以及距离关系等统计规律.相比理想电导体（PEC）模型,本文提出的介质模型更接近复杂的真实环境,模拟结果更趋近于测量值.另外,研究信号在时间尺度上频率衰落的特征,结合相位分布,更加全面地描述信道的多径特征.城市环境中电磁波的传播特征研究有助于新一代微蜂窝无线系统的规划设计,特别是天线种类和摆放位置的选择.

英文摘要：

Based on the Monte Carlo simulations of solving two-dimensional Maxwell equations,we analyzed the statistical distributions of signal amplitude and phase in urban buildings that were modeled as dielectric profiles in this paper.In particular,spatial variations of transmitted signal,including fast fading,shadow fading and range dependence were thoroughly studied.Owing to the proximity to the complex reality in the dielectric conditions,the simulations results present improved agreements with measurements compared with those obtained in the perfect electric conductor environment.In addition,the characterization of frequency fading in line of the multipath model was conducted.The results substantially contribute to the planning of new generation of micro-cellular mobile radio system,especially the choices of types and placement of antenna.