Comparative Analysis and Modeling of 4G LTE Propagation Using the Okumura-Hata and COST-231 Hata Models, Enhanced with Spatially Correlated Log-Normal Shadowing

Improving radio coverage and quality of service (QoS) is a major challenge for 4G LTE mobile networks, particularly in developing countries characterized by highly heterogeneous propagation environments. This study presents a comparative analysis of the Okumura-Hata and COST-231 Hata propagation models as applied to modeling the radio performance of 4G LTE networks. Both models were enhanced by incorporating spatially correlated log-normal shadowing to better represent the local fluctuations in the radio channel observed in real-world environments. The methodology adopted involves simulating propagation losses, received power, the signal-to-interference-plus-noise ratio (SINR), analytical coverage probabilities, and the performance of multi-cellular LTE networks in urban, suburban, and rural environments. Two-dimensional coverage maps were also generated to evaluate the spatial distribution of radio performance. Internal verification of the consistency of the simulations was performed using complementary statistical metrics, including RMSE, MAE, Pearson’s correlation coefficient, the Nash-Sutcliffe index (NSE), and the Bland-Altman plot. The results show a gradual degradation in radio performance as obstacle density and interference levels increase. Rural environments generally offer more favorable propagation conditions, whereas urban environments impose greater constraints on LTE coverage and quality of service. A comparative analysis of the Okumura-Hata and COST-231 Hata models highlights the value of using them depending on the propagation conditions and frequencies under consideration. In the context of this study, the enhanced COST-231 Hata model appears, at first glance, to be a relevant approach for LTE networks operating at 1800 MHz, particularly due to its frequency range of application and the ability to incorporate corrections related to local propagation characteristics. However, its superiority over the Okumura-Hata model cannot be asserted in general terms and must be confirmed by experimental validation based on independent field measurements. Subject to this caveat, it constitutes a promising basis for the modeling and automatic optimization of LTE networks in Guinea.