Pathloss Determination Using Okumura-Hata Model And Cubic Regression For Missing Data For Oman

Abstract

In this paper, we aim to adapt a propagation model for Salalah (OMAN) as we examine the applicability of Okumura-Hata model in Oman in GSM frequency band. The study is in continuation to the work by authors which was carried out for urban area due to the data obtained from local operator. We accomplish the modification of model by investigating the variation in pathloss between the measured and predicted values, according to the Okumura-Hata propagation model for a cell in Salalah city and then finding the missing experimental data with cubic regression. We also verify our modified model by applying it for other cells. The mean square error (MSE) was calculated between measured path loss values and those predicated on basis of Okumura-Hata model for an open area. The MSE is up to 6dB, which is an acceptable value for the signal prediction. The model gave a significant difference in an open area that allowed necessary changes to be introduced in the model. That error was minimized by subtracting the calculated MSE from the original equation of open area for Okumura-Hata model. Modified equation was also re-verified for another cell in an open area in Oman and gave acceptable results. Theoretical simulation by Okumura Hata Model and the obtained experimental data is compared and analyzed further using a cubic regression on the set of the experimental data. Scatter plot of the experimental data on path loss verses distance reveals a third order polynomial trend in the experimental data. Therefore the cubic regression model was fitted using method of least squares which estimates the parameters by minimizing sum of squares of the white noise. The coefficient of determination of this regression suggested that about 90% variation in path loss can be explained.