Análise da eficiência dos métodos de rádio-localização implementados em sistemas celulares

Abstract

In the recent years, great attention has been paid to the location of the personal mobile stations in cell phone communication systems. The GPS (Global Positioning System) system presents adequate precision presenting information on the location, however there are some aspects of the system that restrict the use, such as the unavailability of the systems in inside environment in metropolitan areas. The developments and the popularity of cell phones has motivated the development of localization methods that, together with the existing radio-localization techniques, as well as with the GPS system itself, are capable of promoting a good result in the localization in outdoor and indoor environment. The localization methods used in cell phone networks are complementary and work in the system in a way so as to provide the localization taking into consideration external factors, such as the density of buildings and base stations, the presence of obstacles and the environment where the localization is requested, that can be inside a building (indoor environment), or outdoors, considered as an external environment. The goal of this work is to analyze the factors that influence the order in which they are chosen and the frequency of use of the localization methods, as well the results of the study of the factors that influence its effectiveness in indoor and outdoor environments of high and low building and base station densities.