GPS Signal Channel Modeling and Verification

Global Positioning System (GPS) is a technology that is used not only for military purposes but also for general positioning in civilian applications. It is often used in applications of Internet of Things (IoT), which have gained popularity in recent years, for example, tracking the daily activities of elderly people, and monitoring vital signs etc. The GPS signal which is extremely weak is affected by several types of errors in the course of its propagation. This situation becomes much worse particularly when the GPS receiver is located in dense urban areas where multipath effect is strongly pronounced. The received signal strength of a GPS satellite at a given location can be predicted by analyzing the propagation characteristics of the channel with an appropriate propagation model. In this paper, we propose a simple MATLAB model to estimate the received signal strength of a GPS signal in varying urban environment based on experimental measurements of the propagation characteristics of GPS signal taken in the city of Izmir, Turkey.