New Modeling Procedure for Indoor/Outdoor Propagation Environments in Micro- and Pico-Cell Wireless Communication Systems

0102253 Iskander通过本提案，PI恭敬地请求NSF支持，以制定一个详细，准确，一种新的3D模型[或者具有高级计算能力的2D模型，例如垂直平面发射（VPL）技术]将在集成三种新的创新方法的基础上发展，以提高计算精度和提高计算效率。这包括使用以下内容：1.一种新的非结构化三角网格射线追踪方法（TGRM），在室外区域建模时可显著节省计算时间。初步结果表明，TGRM方法的CPU时间约为可见光跟踪的30%.基于均匀矩形网格法（URGM），假设反射面和透射面与网格线重合，对室内区域进行空间划分。实验结果表明，室内传播区域均匀网格法的CPU时间约为可见光射线追踪法的14%.用FDTD方法计算复合墙体的反射系数和透射系数，并将这些系数结合到整个射线追踪程序中。这对于短距离信号预测很重要，其中壁的材料属性的平均值或有效值可能提供不准确的预测。多重网格时域有限差分（multigrid FDTD）代码也将用于计算室内和室外物体的衍射系数，这些物体很难解析建模。衍射系数的结果将被纳入一个三维射线跟踪代码，实现上述拟议的程序。衍射系数将作为程序的一部分以数据库和查找表的形式包含在内.建议的射线追踪代码的3D版本的开发将基于在TGRM程序中使用四面体单元和在URGM方法中使用实心矩形单元。所提出的方法不涉及搜索算法，因此在计算效率的显着改善是预期的。从开发的新的传播模型的整体结果将在实验上验证scaledmodels在60 'x40' x23 '室内天线范围可在犹他州的大学。比例模型将被仔细选择，以呈现感兴趣的物理结构，一方面，另一方面，一个对象，可以被用作一个完全可理解的和基于物理的传播模型的发展的积木。利用现有的实验设备（HP 8510高达40 GHz），将有可能使用高达20的比例因子来模拟目前在地面无线通信系统中使用的较高频率（2 GHz）下的实际结构。PI建议使用计算的EM功率分布模式来确定可用于无线通信系统仿真的统计参数。这包括计算覆盖范围、延迟扩散、双恐怖率和到达角度。该项目将涉及两名研究生从事项目的模拟部分，另外一名研究生与一组本科高年级学生一起从事构建比例模型和进行项目的实验验证部分。

0102253IskanderWith this proposal the PI's respectfully request NSF support to develop a detailed, accurate, andcomputationally efficient propagation model for wireless communications in micro- and pico-cell systems.A new 3D model [or alternatively a 2D model with advanced calculation capabilities such as the vertical-plane-launch (VPL) technique] will be developed based on integrating three new and innovativeapproaches to improve calculation accuracy and increase the computational efficiency. This includes theuse of the following:1. A new unstructured triangular grid ray tracing method (TGRM) to provide significant savings incomputational time when modeling outdoor regions. Preliminary results show that CPU time for theTGRM method is approximately 30% of that of the visibility ray tracing.2. A space division procedure based on a uniform rectangular grid method (URGM) for indoor regionsand assuming that the reflection/transmission surfaces coincide with the grid lines. Preliminaryresults show that the CPU time for the proposed uniform grid method for indoor propagation regionsis approximately 14% of that of the visibility ray tracing method.3. An FDTD approach to calculate reflection (F ) and transmission (F ) coefficients of composite wallsand incorporate these coefficients in the overall ray tracing code. This is important for short rangesignal prediction where average or effective values of materials properties of walls may provideinaccurate predictions. The multigrid Finite Difference Time Domain (multigrid FDTD) code willalso be used to calculate diffraction coefficients from indoor and outdoor objects that are difficult tomodel analytically. Diffraction coefficient results will be incorporated with a 3D ray tracing code thatimplements the proposed procedures described above. Diffraction coefficients will be included as partof the program in the form of a database and look-up tables.4. The development of the 3D version of the proposed ray tracing code will be based on using pyramidalor tetrahedral cells in the TGRM procedure, and solid rectangular cells in the URGM method. Theproposed methods do not involve search algorithms and hence significant improvement in thecomputational efficiency is expected. The overall results from the developed new propagation model will be validated experimentally on scaledmodels in the 60'x40'x23' indoor antenna range available at the University of Utah. Scaled models will becarefully selected so as to present physical structures of interest, on the one hand, and an object that can beused as a building block towards the development of a fully understandable and physics-based propagationmodel, on the other. With the available experimental facilities (HP8510 up to 40 GHz), it will be possibleto use scale factors as large as 20 to model realistic structures at the higher frequencies (2GHz) presentlybeing used in terrestrial wireless communication systems.In addition to the development of the deterministic EM-based propagation model, the PI's propose to use the calculated EM power distribution pattern to determine statistical parameters that may be used in thesimulation of wireless communications systems. This includes calculations of coverage, delay spread, biterror rate, and angle of arrival. The project will involve two graduate students to work on the simulationpart of the project, and one additional graduate student together with a team of undergraduate seniorstudents to work on building the scaled models and conducting the experimental verification part of theproject.