In this work Hata, Lee, Walfisch-Ikegami and Free Space Loss models have
been compared with practical path loss based on series of measurements in Karada
district in Baghdad for GSM900 downlink band. Hata model showed the closest
path loss predictions with mean square error = 10.8 dB, but these results are far
from good prediction results and need enhancement. Hata model was optimized
using Least Squares method based on measured received signal power. The
optimized Hata model showed much better results from the original Hata with
mean square error = 6.96 dB. The simulation and calculations were implemented
using MATLAB R2009b. The measurements were done using Field Test Display
(FTD) with a compatible hand phone to measure signal strength. A Ground
Positioning System (GPS) was used to measure the distance from transmitter.