Terrestrial VHF Transmitter Coverage Of TVO (Case Study In Oromia Region)

Abstract

The quality of terrestrial television signal received by viewers is of keen interest to stake holders in the broadcast world. This thesis investigates the coverage areas of television signals in Oromia region and the effect of propagation on signal strength through quantitative measurement of the electric field strength of these signals. The signal strength of the transmitters of the Oromia TV in Oromia regional state from Channel five (5) to twelve(12) or (operating frequency from 175.25MHz to 224.25MHz band III VHF).The method used is such that requires the physical presence of the investigator in all the towns and villages within the State with the necessary instrument to carry out the electric field strength measurements in all the locations the measurement were taken radially along several routes with the transmitting stations as reference. These measurements is taken using field strength Meter and a GPS personal navigator for determining the geographical coordinates as well as the line of sight distances of the various data points from the base stations. Data were taken around the towns and villages in all the Local Government Areas of the regional State as far as road accessibility permits until the signal faded away completely for all 16 channel. It is important to understand the impact of physical surroundings on a propagating signal because the propagation characteristics of any radio channel are severely affected by objects that surround the transmitters and the receivers. Therefore, the propagation characteristics limit the performance of in-building high capacity wireless communications. This thesis adapted some field strength models that are best suitable for Finfine city Oromia regional state, Ethiopia. This is done by optimizing some existing field strength models, which are free space, Hata, ITU-RP.529-3 and ERC Report 68 models to suit Oromia region using a VHF television signal of TVO. The collected data analyzed; processing and computation were carried out using MATLAB and the overall result and finding of coverage of each station shown by Radio mobile software.