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- MakaleAçık Erişim2024Scopus SJRQ2Modified REL-Based Piecewise Path Loss Modeling Approach for Shore-to-Ship Communication at 5.6 GHz
Eyuboglu, Ekrem; Hasirci Tugcu, Zeynep; Kuzulugil, Kenan; Cavdar, Ismail Hakki
The need for reliable and uninterrupted communication systems in the marine environment has become critically important with increasing maritime activities, environmental monitoring, and the spread of autonomous systems. However, the complex structure of electromagnetic wave propagation in a sea environment limits the accuracy of the existing propagation models. Thus, the Modified Round Earth Loss (REL) model was first developed in this study to estimate the path loss more accurately in shore-to-ship communication. Subsequently, a piecewise modeling approach based on the principle of two-segment data modeling was proposed. In the Modified REL model, unlike the traditional REL model, the paths and gains of the direct and reflected waves were not considered equal in the calculations. Moreover, unlike in the classical approach, the receiver height was not taken as a fixed value; the estimated best receiver height value for each measurement was included in the calculations as a representation of the effect of roughness in the sea environment. Thus, the model is better adapted to various environmental conditions. In addition, the proposed piecewise model divides the propagation medium into two regions using a break point calculated by Fresnel zone theory. The Modified REL model was used for the first region and the log-distance model was used for the second region. This method allows for more accurate modeling of signal behaviors, especially at different distances. Experimental measurements and performance evaluations conducted using four different shore-to-ship communication scenarios show that the Modified REL model shows an average improvement of up to 3% in Root Mean Square Error (RMSE) values compared to the classical REL model. Additionally, the proposed piecewise model improves the fitting error of the Modified REL model, which models the data as a single whole, by an average of 22.25%. These findings emphasize the necessity of propagation models that are sensitive and adaptable to environmental changes for maritime communication.
AtıfScopus4WoS2OpenAlex4İncele - MakaleYalnız künye2023Scopus SJRQ1A Proposed V2V Path Loss Model: Log-Ray
Kuzulugil, Kenan; Tugcu, Zeynep Hasirci; Cavdar, Ismail Hakki
Vehicle-to-vehicle (V2V) communication that has prominent involvement in the design of innovative communication solutions for the intelligent transportation system. Therefore, to develop V2V channel models, the knowledge of the propagation channel on which comprehensive research efforts have been carried is vital. In this study, we focused on the analysis and modeling of path loss characteristics for V2V communications and proposed a log-ray path loss model with the motivation of overcoming remarkable fitting errors between the two-ray model and measured data where the path loss exponent corresponds to different from 2. First, channel measurements were performed at 5.9 GHz with commercially available DSRC OBU devices for five different scenarios in typical highway and suburban environments in Gümüşhane, Turkey. Then, the large-scale characteristics of different propagation scenarios were analyzed and the proposed log-ray model performance was compared with commonly used log-distance and two-ray path loss models qualitatively and quantitatively. On the other hand, analysis of small-scale modeling and shadowing were also conducted for all scenarios and presented in the results. The findings clearly demonstrate that the proposed log-ray path loss model fits the measured data with a smaller RMSE value (2.54 dB) than the results of the log-distance (3.07 dB) and two-ray (3.72 dB) path loss models in the literature. In other words, the proposed model has approximately 17.5% and 32% increase in fitting performance according to the log-distance and the two-ray path loss models, respectively. The study results will be helpful for better performance analysis and system design of V2V communication.
AtıfScopus13WoS11OpenAlex12İncele