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

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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.