DIFFRACTION AROUND CORNERS AND ITS EFFECTS ON THE MICROCELL COVERAGE AREA IN URBAN AND SUBURBAN ENVIRONMENTS AT 900-MHZ, 2-GHZ, AND 6-GHZ

For rectilinear streets in urban and suburban environments, a theoreti cal model has been developed to characterize signal propagation around corners. Ray theory and the uniform geometrical theory of diffraction (UTD) were combined to predict the spatial average of signal strength . The model was compared with data measured at 900 MHz, 2 GHz, and 6 G Hz. The results show excellent agreement between theory and measuremen ts for different bands and different locations. This indicates that ac curate prediction of signal and interference levels is possible throug h simulation rather than costly field measurements. Using building and street databases, model can be used to predict the signal coverage an d interference in large cities, thus allowing system designers to dete rmine cell layouts, reuse factors, capacity, etc. Furthermore, theoret ical microcell coverage areas were determined and compared to existing diamond-shape models at 900 MHz and 2 GHz with the base-station anten na located in the intersection. The theoretical and empirical results were in very good agreement.