# Second-Order Statistical Properties of Vehicle-to-Vehicle Rician Fading Channel
## 5 Conclusions  
This paper presents a simplified 2D theoretical model of a narrow-band SGTR model for the V2V Rician fading channel, enhancing the understanding of second-order statistical properties in V2V communication systems. The model analyzes LCR and AFD in detail, demonstrating the significant impact of key parameters such as Tx-Rx movement direction, Tx-Rx distance separation, scattering mean angle, angle spread, and scattering shape and region. The model accurately captures the effects of high VDT and closely matches the theoretical results with measured data, and hence validating its accuracy for V2V system performance evaluation.  
The findings in these studies provide a clear pathway and directly influence the design of a V2V system in several ways: the SB rays exhibit increased sensitivity to Tx-Rx movement, impacting the LCR and AFD due to their inter-dependent relationship of AoA and AoD. Additionally, the variations in the angle spread and mean angle channel parameters exhibits a trend in the crossings and threshold of the LCR and AFD. Furthermore, the LCR and AFD show lower crossing rates as the Tx-Rx distance decreases, with an increasing \(K\)-factor indicating stronger LoS dominance. When comparing the LCR and AFD at a high VTD and low VTD, they consistently exhibit wider and flatter peaks, suggesting increased signal fluctuation due to multipath and rapid environmental changes.  
By understanding the detailed analysis of parameter adjustments and impact on LCR and AFD, it can guide toward the adjustments of the parameters in real-world applications; also, designers can optimize V2V communication systems for a more robust V2V network. Most importantly, the strong alignment between theoretical results and empirical data confirms model accuracy, promoting its application in real-world scenarios.  
Future research could leverage machine learning to enhance predictive capabilities and refine the model's accuracy in dynamic environments. Investigating the impact of varying environmental conditions and extending the model to multi-user scenarios in dense urban settings would provide deeper insights. Real-time implementation and testing in practical V2V systems will be crucial for validating the model's effectiveness, paving the way for more robust and reliable V2V communication solutions.  
Figure 6: Theoretical model vs. measured data for LCRs and AFDs: (**a**) plot for LCR; (**b**) plot for AFD.  
**Author Contributions:** Conceptualization, S.A., A.A., E.E. and M.C.; methodology, S.A., A.A. and E.E.; software, S.A., A.A. and E.E.; validation, S.A., A.A. and E.E.; formal analysis, S.A., A.A. and E.E.; investigation, S.A., A.A. and E.E.; resources, S.A., A.A., M.C. and E.E.; data curation, S.A. and E.E.; writing--original draft preparation, S.A., A.A. and E.E.; writing--review and editing, A.A. and E.E.; visualization, E.E.; supervision, E.E. and A.A.; project administration, M.C., A.A. and M.C.; funding acquisition, M.C., A.A. and E.E. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Data Availability Statement:** Data are contained within the article.  
**Conflicts of Interest:** The authors declare no conflicts of interest.