Radio wave propagation measurement and modeling in wireless communication environments

A key step in the optimal design of wireless communication systems is the understanding of the propagation of radio waves through wireless channels. As wireless communications become more ubiquitous, new propagation environments emerge and the propagation mechanisms therein should be investigated. This dissertation studies the radio wave propagation for two such environments: indoor stairwells and building facades.;For stairwells, extensive field measurements, numerical simulations and theoretical analysis are employed to examine the propagation mechanisms such as depolarization in these environments. In particular, the values of path loss exponent n have been extracted from the measurements in four distinct stairwells. These n-values are then compared with those in multifloor indoor environments and new approaches are introduced to analyze the path loss characteristics. An empirical path loss formula is subsequently developed for indoor stairwell propagation environments at two frequency bands -- 2.4 GHz and 5.8 GHz. These research findings advance a better understanding of the radio wave propagation in indoor stairwells and provide practical propagation models for the design of wireless communication systems in those environments.;As for the building facades, in addition to the understanding of various propagation mechanisms, we address an important issue in propagation modeling using ray tracing method. Since the structures of building facades are complicated, it is common to replace them with simpler structures such as flat slabs that fit the ray tracing method. This dissertation investigates the feasibility of such simplification and finds out how much accuracy will thus be compromised. Besides the many measurements that have been conducted in these complex environments, a scaled periodic structure for simulating the building facades has been built and placed inside an anechoic chamber to further examine the propagation mechanism and for validating the accuracy of ray tracing method.;In summary, this dissertation contributes to the fundamental understanding of radio wave propagation in complex environments. Furthermore, these results will directly benefit the design of wireless communication systems such as micro-, pico-, and femtocells. Finally, the results will also help researchers and users of ray tracing algorithm/software decide to what degree to simplify their building facade models or similar structures.