volume | PIER Journals

Abstract

Millimeter-wave (mmWave) frequencies are considered as candidate bands for 5G/6G mobile networks. Diffraction models are significant for predicting non-line-of-sight (NLOS) wireless channels while it is shown that the line of sight (LOS) path is usually blocked by buildings in urban area environments. A lot of investigations on the diffraction loss have been performed, and most of them just considered a one obscuring object and a short propagation distance. In this paper, we conduct a statistical analysis of the diffraction loss in the outdoor NLOS in Urban Micro Cell, considering a transmitter (TX) and a receiver (RX) which are located at an aggregation point on the roof of a building. We have focused on analyzing the diffraction loss suffered by mmWave signals when they hit one or two obscuring points located over rooftop of the buildings. The objects have different heights located at various distances between TX and RX. We have considered the bands: 28 GHz, 38 GHz, 60 GHz, 73 GHz and 100 GHz. The analysis is based on the diffraction model named the Knife Edge Diffraction (KED). We have strictly followed the ITU Recommendations ITU-R P.526-15 (10/2019). In this work, we use two schemes that characterize the KED model, namely Single KED (SKED) and Double Isolated KED (DIKED). Different scenarios are performed by varying different parameters of the channel between TX and RX. The results show that the diffraction loss is inversely proportional to the distance between the obscuring object and the transmitter, the wavelength, and the distance between the TX and RX.

1. FCC Press Release, Mar. 2019. Available: https://docs.fcc.gov/public/attachments/DOC-356588A1.pdf.
doi:10.1109/MWC.2019.8700131

2. Marcus, M. J., "Progress in opening access to spectrum above 100 GHz," IEEE Wireless Communications, Vol. 26, No. 2, 2-3, 2019.

3. Rec. ITU-R P.1411-8 "Propagation data and prediction methods for the planning of short-range outdoor radiocommunication systems and radio local area networks in the frequency range 300 MHz to 100 GHz," ITU-R Recommendation, Vol. 8, P Series, ITU, Geneva, July 2015.
doi:10.1109/TAP.2020.2970036

4. Zhan, Q., Y. Fang, M. Zhuang, et al. "Stabilized DG-PSTD method with non conformal meshes for electromagnetic waves," IEEE Transactions on Antennas and Propagation, Vol. 68, No. 6, 4714-4726, 2020.
doi:10.1109/TAP.2021.3111639

5. Zhan, Q., Y. Wang, Y. Fang, et al. "An adaptive high-order transient algorithm to solve large-scale anisotropic Maxwell's equations," IEEE Transactions on Antennas and Propagation, Vol. 70, No. 3, 2082-2092, 2021.
doi:10.1109/MVT.2015.2410341

6. Viriyasitavat, W., M. Boban, H.-M. Tsai, et al. "Vehicular communications: Survey and challenges of channel and propagation models," IEEE Vehicular Technology Magazine, Vol. 10, No. 2, 55-66, 2015.

7. Zekri, A. B., R. Ajgou, and M. Hettiri, "Impact of azimuth and elevation half power beam width on human blockage scenarios in mmWave channels," Proceedings of the IEEE 1st International Conference on Communications, Control Systems and Signal Processing (CCSSP), 41-45, IEEE, El Oued, Algeria, May 2020.

8. Ahamed, M. M. and S. Faruque, "Propagation factors affecting the performance of 5G millimeter wave radio channel," Proceeding of the IEEE International Conference on Electro Information Technology (EIT), 728-733, Grand Forks, ND, USA, May 2016.

9. Abdulrasool, A. S., J. S. Aziz, and S. J. Abou-Loukh, "Calculation algorithm for diffraction losses of multiple obstacles based on Epstein-Peterson approach," International Journal of Antennas and Propagation, Vol. 2017, Article ID 3932487, 9 pages, 2017, https://doi.org/10.1155/2017/3932487.
doi:10.1109/8.14401

10. Walfisch, J. and H. L. Bertoni, "A theoretical model of UHF propagation in urban environments," IEEE Transactions on Antennas and Propagation, Vol. 36, No. 12, 1788-1796, 1988.
doi:10.1109/JSTSP.2016.2527364

11. Hur, S., S. Baek, B. Kim, et al. "Proposal on millimeter-wave channel modeling for 5G cellular system," IEEE Journal of Selected Topics in Signal Processing, Vol. 10, No. 3, 454-469, 2016.
doi:10.1109/TAP.2013.2297164

12. Lu, J. S., H. L. Bertoni, K. A. Remley, et al. "Site-specific models of the received power for radio communication in urban street canyons," IEEE Transactions on Antennas and Propagation, Vol. 62, No. 4, 2192-2200, 2014.

13. Mcnamara, D. A. and C. Pistotius, Introduction to the Uniform Geometrical Theory of Diffraction, 488, Artech House Microwave Library, 1990.
doi:10.1109/TAP.1956.1144427

14. Keller, J., "Diffraction of a convex cylinder," IRE Transactions on Antennas and Propagation, Vol. 4, No. 3, 312-321, 1956.
doi:10.1109/PROC.1974.9651

15. Kouyoumjian, R. G. and P. H. Pathak, "A uniform geometrical theory of diffraction for an edge in a perfectly conducting surface," Proceedings of the IEEE, Vol. 62, No. 11, 1448-1461, 1974.
doi:10.1109/TAP.1980.1142396

16. Pathak, P., W. Burnside, and R. Marhefka, "A uniform GTD analysis of the diffraction of electromagnetic waves by a smooth convex surface," IEEE Transactions on Antennas and Propagation, Vol. 28, No. 5, 631-642, 1980.
doi:10.1109/TAP.1984.1143189

17. Luebbers, R., "Finite conductivity uniform GTD versus knife edge diffraction in prediction of propagation path loss," IEEE Transactions on Antennas and Propagation, Vol. 32, No. 1, 70-76, 1984.

18. Kim, K.-W., et al. "Diffraction loss model based on 28 GHz over-rooftop propagation measurements," Proceeding of the IEEE 86th Vehicular Technology Conference (VTC-Fall), Toronto, ON, Canada, September 2017.
doi:10.4218/etrij.2019-0411

19. Kim, K.-W., M.-D. Kim, J. Lee, et al. "Millimeter-wave diffraction-loss model based on over-rooftop propagation measurements," ETRI Journal, Vol. 42, No. 6, 827-836, 2020.

20. Tervo, N., et al. "Diffraction measurements around a building corner at 10 GHz," Proceeding of the IEEE 1st International Conference on 5G for Ubiquitous Connectivity, Akaslompolo, Finland, November 2014.
doi:10.1109/TAP.2017.2734159

21. Rappaport, T. S., G. R. Maccartney, S. Sun, et al. "Small-scale, local area, and transitional millimeter wave propagation for 5G communications," IEEE Transactions on Antennas and Propagation, Vol. 65, No. 12, 6474-6490, 2017.

22. Lu, J. S., et al. "Measurement and characterization of various outdoor 60 GHz diffracted and scattered paths," Proceeding of the IEEE MILCOM 2013 --- 2013 Military Communications Conference, Diego, CA, USA, November 2013.
doi:10.1109/8.660975

23. Anderson, H. R., "Building corner diffraction measurements and predictions using UTD," IEEE Transactions on Antennas and Propagation, Vol. 46, No. 2, 292-293, 1998.

24. Recommendation ITU-R P.526-15 "Propagation by diffraction,", 2019.

25. Viswanathan, M., Wireless Communications Systems in MATLAB, 2nd Ed., June 8, 2020.

26. Jacob, M., S. Priebe, A. Maltsev, et al. "A ray tracing based stochastic human blockage model for the IEEE 802.11 ad 60 GHz channel model," Proceedings of the IEEE 5th European Conference on Antennas and Propagation (EUCAP), 3084-3088, Rome, Italy, April 2011.

27. Kunisch, J. and J. Pamp, "Ultra-wideband double vertical knife-edge model for obstruction of a ray by a person," Proceeding of the IEEE International Conference on Ultra-Wideband, 17-20, Hannover, Germany, September 2008.
doi:10.1109/TMTT.2011.2178859

28. Jacob, M., S. Priebe, R. Dickhoff, et al. "Diffraction in mm and sub-mm wave indoor propagation channels," IEEE Transactions on Microwave Theory and Techniques, Vol. 60, No. 3, 833-844, 2012.

29. Ghasemi, A., A. Abedi, and F. Ghasemi, Propagation Engineering in Wireless Communications, Springer, New York, NY, USA, 2016.

30. Takada, J.-I., K. Murakami, P. Hanpinitsak, et al. "Experimental evaluation of over-the-rooftop propagation loss prediction model for the spectrum sharing at 26 GHz band," International Applied Computational Electromagnetics Society Symposium (ACES), 1-3, IEEE, Hamilton, ON, Canada, August 2021.

31. Ellis, T. and S. Weiss, "Propagation prediction for rail communications in urbanized areas," Proceedings of the 2018 Joint Rail Conference, 2018 Joint Rail Conference, Pittsburgh, Pennsylvania, USA, April 18-20, 2018, V001T03A006, ASME, https://doi.org/10.1115/JRC2018-6196.
doi:10.1109/TAP.2004.829405

32. Asen, W., "Comparison of measurements with prediction methods for propagation by diffraction at 88-108 MHz," IEEE Transactions on Antennas and Propagation, Vol. 52, No. 6, 1499-1504, 2004.
doi:10.1007/978-1-4419-9152-2

33. Sheikh, A. U. H., Wireless Communications: Theory and Techniques, Springer Science & Business Media, 2004.
doi:10.1587/transcom.2017EBP3255

34. Sasaki, M., M. Inomata, W. Yamada, et al. "Path loss model considering blockage effects of traffic signs up to 40 GHz in urban microcell environments," IEICE Transactions on Communications, Vol. 101, No. 8, 1891-1902, 2018.

Dr. Abdelbasset Bedda Zekri

Dr. Riadh Ajgou