DEVELOPMENT OF PATH LOSS MODEL FOR ORANGE FM RADIO STATION IN ONDO STATE, NIGERIA

Abstract

The measurement of the electric field strength distribution of Orange FM radio station, Akure, Ondo State transmitting on 94.5 MHz was conducted round the stretch of the coverage areas. The latitude, longitude, elevation and line of sight distance to the transmitter base were measured at every access point at 4 km intervals from each other using Global Positioning System Receiver “Garmin Handheld Personal Navigator (GPS-72)”, while the field strengths were measured with CATV S110 digital signal level meter. Measurements were taken along four (4) major routes away from the transmitter base. The path loss values were calculated from the electric field strength measured in all the routes and the path losses were plotted against line of sight distances. For each route, least square regression analyses were carried out on each plot and a sub-model was developed therefrom. The four submodels were later averaged to form a single model for the considered routes. Comparative evaluation between the developed path loss model and two of the existing models (Egli and Free Space Path Loss (FSPL)) were carried out as well. Root Mean Square Error (RMSE) was calculated for each sub-model. From the RMSE results analyses, the Egli model generated lesser values (compared to the FSPL) which are within acceptable range (that is, RMSE < 6dB for all the routes). This showed that the developed model did not over-predict the path loss. The developed model will enable the broadcasting companies to determine the coverage of their transmitter and improve on the areas with poor signal reception. The information from this developed model prediction can be a useful tool for link budget design for Orange FM station in Akure, Ondo State. It will also provide a broad idea of path losses of FM signals to radio engineers operating in this environment.The model is therefore valid and can be used to estimate path loss of Orange FM 94.5 MHZ signals in Akure, Ondo State, Nigeria.