VHF Radiowave propagation measurements in Minna, North Central Nigeria

Abstract

In designing an efficient radio communication system, the engineer is faced with the task of being able to predict the behaviour of the radio signal from the transmitter to the receiver and in doing this, preliminary calculations including the expected signal strength at the receiver has to be made. Signal strength measurement was made from a broadcasting station transmitting at a frequency of 92.3 MHz along a 14.85 Km path. The results obtained show that received signal strength (RSS) values were higher during the wet season as compared to lower values recorded during the dry season for the link. Also, the RSS was higher during the morning and evening/night hours while lower values were recorded during the afternoon time. Signal attenuation caused by atmospheric and environmental losses was calculated and for the dry season, average clear-air attenuation fluctuated between -2 dB to 2.3 dB while wet season values fluctuated between 0 dB and -2.9 dB. Also, the RSS was modeled using ITU-R P.526-12 to predict path losses due to diffraction over the earth’s curvature and result obtained reveal that this model underestimated the RSS for the radio link while 206 (12.46%) enhanced field strength was recorded out of the measured 1,639 data.