Prediction of propagation path loss for stratospheric platforms mobile communications in urban site LOS/NLOS environment

Recently, there are of great interests on employing stratospheric platform as a new means of providing IMT-2000. One important issue that has not been much investigated is the propagation characteristic of its link. This paper aims at evaluating the impact of elevation and azimuth angles variation to the propagation mechanism in urban environment for mobile communication link. In order to examine the propagation loss experienced by this system in urban area, we developed the building block model and the ray tracing tool for simulation. We then apply the ray tracing tool with respect to the angle variations. As a result, propagation loss as a function of elevation and azimuth angles is obtained. We compared the result with a physical-statistical model for verification. Finally, link budget analysis and estimation to the required transmitted power at several transmission rates for the application of EVIT-2000 is observed. Different scenario, which means different azimuth angles clearly show the critical limitations for mobile communication using a concept of stratospheric platform.