volume | PIER Journals

Abstract

Millimeter-wave (mmWave) radio communication systems, essential to the advancement of future networks, are highly susceptible to link degradation caused by human body obstruction. This paper presents a comprehensive experimental study of fast fading phenomena induced by pedestrians crossing indoor mmWave links, specifically at 40 GHz and 60 GHz. The measurement campaign was conducted in a realistic access point to user equipment configuration, involving over 150 participants and yielding 604 fading events, of which 431 involved full line-of-sight (LOS) blockage. The analysis focuses on the statistical characterization of the deep-fade regions within these events. Results are compared with simulations based on the Knife-Edge Diffraction (KED) model to evaluate its accuracy under dynamic blockage conditions. The statistical analysis reveals that the Weibull distribution most effectively models the fast fading observed during human-induced blockage, outperforming Rician, Rayleigh, Nakagami-m, and Normal distributions - particularly at 60 GHz, where 89% of fades aligned with the Weibull model. Simulated fades using the KED model, however, did not show a strong fit with a single distribution yielding similar results to the Rician, Weibull, and Nakagami-m. These findings underscore the influence of diffracted multipath components in determining the statistical behavior of fast fading. The study confirms the limitations of existing diffraction models in capturing the full complexity of dynamic human blockage and highlights the need for refined modeling approaches. This work contributes critical insights toward the robust design and performance prediction of future indoor mmWave communication systems.

1. Schwarz, R., "WLAN at 60 GHz, a technology introduction," https://scdn.rohde-schwarz.com/ur/pws/dl downloads/dl application/application notes/1ma220/1MA220 3e WLAN 11ad WP.pdf, 2017.

2. Alejos, Ana Vázquez, Manuel García Sanchez, and Iñigo Cuinas, "Measurement and analysis of propagation mechanisms at 40 GHz: Viability of site shielding forced by obstacles," IEEE Transactions on Vehicular Technology, Vol. 57, No. 6, 3369-3380, Nov. 2008.
doi:10.1109/tvt.2008.920052 Google Scholar

3. Cuiñas, Iñigo and Manuel García Sánchez, "Permittivity and conductivity measurements of building materials at 5.8 GHz and 41.5 GHz," Wireless Personal Communications, Vol. 20, No. 1, 93-100, 2002.
doi:10.1023/a:1013886209664 Google Scholar

4. Cuiñas, Iñigo, Jean-Pierre Pugliese, Akram Hammoudeh, and Manuel García Sánchez, "Frequency dependence of dielectric constant of construction materials in microwave and millimeter-wave bands," Microwave and Optical Technology Letters, Vol. 30, No. 2, 123-124, 2001.
doi:10.1002/mop.1238 Google Scholar

5. Leonor, Nuno R., Rafael F. S. Caldeirinha, Telmo R. Fernandes, David Ferreira, and Manuel García Sánchez, "A 2D ray-tracing based model for micro- and millimeter-wave propagation through vegetation," IEEE Transactions on Antennas and Propagation, Vol. 62, No. 12, 6443-6453, Dec. 2014.
doi:10.1109/tap.2014.2362124 Google Scholar

6. Alejos, Ana V., Lourdes Pereira, M. Garcia Sanchez, and M. Dawood, "Development of 3D human tissues phantoms for analysis of frequency dispersion and human body interaction at 60 GHz," 2015 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), 368-368, Vancouver, BC, Canada, 2015.
doi:10.1109/USNC-URSI.2015.7303652

7. MacCartney, George R., Theodore S. Rappaport, and Sundeep Rangan, "Rapid fading due to human blockage in pedestrian crowds at 5G millimeter-wave frequencies," GLOBECOM 2017 --- 2017 IEEE Global Communications Conference, 1-7, Singapore, 2017.
doi:10.1109/GLOCOM.2017.8254900

8. Senic, Jelena, Anmol Bhardwaj, Camillo Gentile, Derek Caudill, Chiehping Lai, Damir Senic, Sung Yun Jun, Jack Chuang, Jian Wang, Anuraag Bodi, Raied Caromi, and Nada Golmie, "Challenges for 5G and beyond," 2022 16th European Conference on Antennas and Propagation (EuCAP), 1-5, Madrid, Spain, 2022.
doi:10.23919/EuCAP53622.2022.9769413

9. Alyosef, Ayham, Stamatia Rizou, Zaharias D. Zaharis, Pavlos I. Lazaridis, Ahmed M. Nor, Octavian Fratu, Simona Halunga, Traianos V. Yioultsis, and Nikolaos V. Kantartzis, "A survey on the effects of human blockage on the performance of mmWave communication systems," 2022 IEEE International Black Sea Conference on Communications and Networking (BlackSeaCom), 249-253, Sofia, Bulgaria, 2022.
doi:10.1109/BlackSeaCom54372.2022.9858201

10. Testolina, Paolo, Mattia Lecci, Alessandro Traspadini, and Michele Zorzi, "An open framework to model diffraction by dynamic blockers in millimeter wave simulations," 2022 20th Mediterranean Communication and Computer Networking Conference (MedComNet), 9-17, Pafos, Cyprus, 2022.
doi:10.1109/MedComNet55087.2022.9810361

11. Salous, Sana, Yubei He, Jiahao Hu, Amar Al-Jzari, and Silvi Kodra, "Human blockage measurements using multiband CW sounder," 2025 19th European Conference on Antennas and Propagation (EuCAP), 1-5, Stockholm, Sweden, 2025.
doi:10.23919/EuCAP63536.2025.10999192

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

13. Anglès-Vázquez, Albert, Erick Carreño, and Luciano S. Ahumada, "Modeling the effect of pedestrian traffic in 60-GHz wireless links," IEEE Antennas and Wireless Propagation Letters, Vol. 16, 1927-1931, 2017.
doi:10.1109/lawp.2017.2688926 Google Scholar

14. Ahumada Fierro, Luciano, Erick Carreño Maggi, Albert Anglès Vazquez, and Demian Schkolnik, "Empirical results for human-induced shadowing events for indoor 60 GHz wireless links," IEEE Access, Vol. 8, 44522-44533, 2020.
doi:10.1109/access.2020.2978453 Google Scholar

15. Jacob, Martin, Sebastian Priebe, Alexander Maltsev, Artyom Lomayev, Vinko Erceg, and Thomas Kürner, "A ray tracing based stochastic human blockage model for the IEEE 802.11 ad 60 GHz channel model," Proceedings of the 5th European Conference on Antennas and Propagation (EUCAP), 3084-3088, Rome, Italy, 2011.

16. Zhang, Peize, Pekka Kyösti, Mikkel Bengtson, Veikko Hovinen, Klaus Nevala, Joonas Kokkoniemi, and Aarno Pärssinen, "Measurement-based characterization of D-band human body shadowing," 2023 17th European Conference on Antennas and Propagation (EuCAP), 1-5, Florence, Italy, 2023.
doi:10.23919/EuCAP57121.2023.10132978

17. MacCartney, George R., Sijia Deng, Shu Sun, and Theodore S. Rappaport, "Millimeter-wave human blockage at 73 GHz with a simple double knife-edge diffraction model and extension for directional antennas," 2016 IEEE 84th Vehicular Technology Conference (VTC-Fall), 1-6, Montreal, QC, Canada, 2016.
doi:10.1109/VTCFall.2016.7881087

18. Kunisch, Jurgen and Jorg Pamp, "Ultra-wideband double vertical knife-edge model for obstruction of a ray by a person," 2008 IEEE International Conference on Ultra-Wideband, Vol. 2, 17-20, Hannover, Germany, 2008.
doi:10.1109/ICUWB.2008.4653341

19. Tran, Ngochao, Tetsuro Imai, and Yukihiko Okumura, "Study on characteristics of human body shadowing in high frequency bands: Radio wave propagation technology for future radio access and mobile optical networks," 2014 IEEE 80th Vehicular Technology Conference (VTC2014-Fall), 1-5, Vancouver, BC, Canada, 2014.
doi:10.1109/VTCFall.2014.6966190

20. Mukherjee, Swagato, Gregory Skidmore, Tarun Chawla, Anmol Bhardwaj, Camillo Gentile, and Jelena Senic, "Scalable modeling of human blockage at millimeter-wave: A comparative analysis of knife-edge diffraction, the uniform theory of diffraction, and physical optics against 60 GHz channel measurements," IEEE Access, Vol. 10, 133643-133654, 2022.
doi:10.1109/access.2022.3231812 Google Scholar

21. Bhardwaj, Anmol, Derek Caudill, Camillo Gentile, Jack Chuang, Jelena Senic, and David G. Michelson, "Geometrical-empirical channel propagation model for human presence at 60 GHz," IEEE Access, Vol. 9, 38467-38478, 2021.
doi:10.1109/access.2021.3063655 Google Scholar

22. Galeote-Cazorla, Juan E., Alejandro Ramírez-Arroyo, Salvador Moreno-Rodríguez, José-María Molina-García-Pardo, María-Teresa Martinez-Inglés, Pablo Padilla, and Juan F. Valenzuela-Valdés, "A study on W-band frequency attenuation in the presence of human blockage," 2024 18th European Conference on Antennas and Propagation (EuCAP), 1-5, Glasgow, United Kingdom, 2024.
doi:10.23919/EuCAP60739.2024.10501008

23. Rappaport, Theodore S., George R. MacCartney, Shu Sun, Hangsong Yan, and Sijia Deng, "Small-scale, local area, and transitional millimeter wave propagation for 5G communications," IEEE Transactions on Antennas and Propagation, Vol. 65, No. 12, 6474-6490, Dec. 2017.
doi:10.1109/tap.2017.2734159 Google Scholar

24. Topal, Ozan Alp, Mustafa Ozger, Dominic Schupke, Emil Björnson, and Cicek Cavdar, "mmWave communications for indoor dense spaces: Ray-tracing based channel characterization and performance comparison," ICC 2022 --- IEEE International Conference on Communications, 516-521, Seoul, Korea, 2022.
doi:10.1109/ICC45855.2022.9839280

25. Doeker, Tobias, Malte Eggers, Carla E. Reinhardt, Daniel M. Mittleman, and Thomas Kürner, "Human motion sensing through blockage and reflection measurements at 60 GHz and 300 GHz," IEEE Access, Vol. 13, 97997-98005, 2025.
doi:10.1109/access.2025.3573681 Google Scholar

26. Plouhinec, Eric and Bernard Uguen, "Knife-edge diffraction models for human body shadowing prediction," 2022 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications (APWC), 36-41, Cape Town, South Africa, 2022.
doi:10.1109/APWC49427.2022.9900051

27. Jacob, Martin, Christian Mbianke, and Thomas Kürner, "A dynamic 60 GHz radio channel model for system level simulations with MAC protocols for IEEE 802.11ad," IEEE International Symposium on Consumer Electronics (ISCE 2010), 1-5, Braunschweig, Germany, 2010.
doi:10.1109/ISCE.2010.5523241

28. "IEEE Standard on Transitions, Pulses, and Related Waveforms," 1-60, IEEE Std 181-2003, Jul. 2003.
doi:10.1109/IEEESTD.2003.94394

29. Parsons, J. D., The Mobile Radio Propagation Channel, 2nd Ed., John Wiley & Sons, Inc., 2001.

30. Shepherd, N. H., "Radio wave loss deviation and shadow loss at 900 MHz," IEEE Transactions on Vehicular Technology, Vol. 26, No. 4, 309-313, Nov. 1977.
doi:10.1109/t-vt.1977.23699 Google Scholar

31. Sagias, N. C., G. K. Karagiannidis, P. S. Bithas, and P. T. Mathiopoulos, "On the correlated weibull fading model and its applications," 2005 IEEE 62nd Vehicular Technology Conference, 2149-2153, Dallas, TX, USA, 2005.
doi:10.1109/VETECF.2005.1558500

32. Jeba, Humayra Anjumee, Anna Gaydamaka, and Dmitri Moltchanov, "Distinguishing micromobility and blockage in 6G sub-THz systems: A machine learning approach," IEEE Open Journal of the Communications Society, Vol. 6, 7810-7822, 2025.
doi:10.1109/ojcoms.2025.3599666 Google Scholar

33. Zhinuk, Fariha, Anna Gaydamaka, Dmitri Moltchanov, and Yevgeni Koucheryavy, "Spectral-based proactive blockage detection for sub-THz communications," IEEE Communications Letters, Vol. 28, No. 7, 1703-1707, Jul. 2024.
doi:10.1109/lcomm.2024.3397743 Google Scholar

34. Moerman, Arno, Olivier Caytan, Hendrik Rogier, and Sam Lemey, "Millimeter-wave distributed antenna systems for interactive virtual reality: Reducing blockage and exposure and enhancing robustness with (air-filled) substrate-integrated waveguide antennas. [Bioelectromagnetics]," IEEE Antennas and Propagation Magazine, Vol. 67, No. 4, 67-78, Aug. 2025.
doi:10.1109/map.2025.3578904 Google Scholar

35. Neha, B. S., "Human blockage modelling in mmWave link," 2025 3rd International Conference on Smart Systems for Applications in Electrical Sciences (ICSSES), 1-6, Tumakuru, India, 2025.
doi:10.1109/ICSSES64899.2025.11009610

Dr. Miguel Riobó Prieto

Dr. Manuel García Sánchez

Prof. Inigo Cuinas