volume | PIER Journals

Abstract

The Coefficient of Variation (CoV) is investigated, studied, and proposed as an alternative and important performance metric to describe the effects of handset orientation on the capacity of Multiple-Input-Multiple-Output (MIMO) systems. We combine 3-D simulated radiation patterns of a base station and handset and their associated scattering parameters in two anisotropic propagation environments. The capacity is evaluated as the handset rotates about the X-Y-Z axes using standard Euler's angles. The coefficient of variation is numerically derived by rotating the handset over the Euler angles (φ, θ, ψ) in each direction every 15° about each axis over a full sphere where each rotation involves the creation of numerous instances of the propagation environment depending on the statistical robustness of the results sought. Three antenna array geometries operating at a frequency of 2.45 GHz are examined using two different propagation channel models (TGnB and TGnF) to verify the validity of the proposed approach. The derived results suggest that the proposed CoV is an effective and practical reasonable metric in selecting the best antenna system design, where ``best'' here refers to the design with the ability to reach the highest throughput of the designs considered.

1. Lehne, P. H., K.Mahmood, A. A. Glazunov, et al. "Measuring user-induced randomness to evaluate smart phone performance in real environments," 2015 9th European Conference on Antennas and Propagation (EuCAP), 1-5, Apr. 2015.

2. Al-Wahhamy, A., N. E. Buris, H. M. Al-Rizzo, and S. Yahya, "An efficient paradigm for evaluating the channel capacity of closed-loop massive MIMO systems," Progress In Electromagnetics Research C, Vol. 98, 1-16, 2020.
doi:10.2528/PIERC19082806

3. Al-Wahhamy, A., H. Al-Rizzo, and N. E. Buris, "Efficient evaluation of massive MIMO channel capacity," IEEE Syst. J., Vol. 14, No. 1, 614-620, Mar. 2020.
doi:10.1109/JSYST.2019.2900006

4. Isaac, A. A., H. Al-Rizzo, S. Yahya, A. Al-Wahhamy, and S. Abushamleh, "Decoupling of two closely-spaced planar monopole antennas using two novel printed-circuit structures," Microw. Opt. Technol. Lett., Vol. 60, No. 12, 2954-2963, Dec. 2018.
doi:10.1002/mop.31405

5. Abbosh, A., H. Al-Rizzo, S. Yahya, and A. Al-Wahhamy, "Decoupling and MIMO performance of two planar monopole antennas with protruded strips," Microw. Opt. Technol. Lett., Vol. 60, No. 11, 2712-2718, Nov. 2018.
doi:10.1002/mop.31487

6. Isaac, A. A., H. Al-Rizzo, S. Yahya, A. Al-Wahhamy, and S. Z. Tariq, "Miniaturised MIMO antenna array of two vertical monopoles embedded inside a planar decoupling network for the 2.4 GHz ISM band," IET Microwaves, Antennas Propag., Vol. 14, No. 1, 132-140, Jan. 2020.
doi:10.1049/iet-map.2018.5069

7. Soltani, M. D., A. A. Purwita, Z. Zeng, H. Haas, and M. Safari, "Modeling the random orientation of mobile devices: Measurement, analysis and LiFi use case," IEEE Trans. Commun., Vol. 67, No. 3, 2157-2172, Mar. 2019.
doi:10.1109/TCOMM.2018.2882213

8. Soltani, M. D., H. Kazemi, M. Safari, and H. Haas, "Handover modeling for indoor Li-Fi cellular networks: The effects of receiver mobility and rotation," 2017 IEEE Wireless Communications and Networking Conference (WCNC), 1-6, Mar. 2017.

9. Purwita, A. A., M. Dehghani Soltani, M. Safari, and H. Haas, "Impact of terminal orientation on performance in LiFi systems," 2018 IEEE Wireless Communications and Networking Conference (WCNC), 1-6, Apr. 2018.

10. Almesaeed, R., A. S. Ameen, A. Doufexi, and A. R. Nix, "Exploiting the elevation dimension of MIMO system for boosting handset capacity," 2015 IEEE International Conference on Communication Workshop (ICCW), 1281-1285, Jun. 2015.
doi:10.1109/ICCW.2015.7247354

11. Mellios, E., Z. Mansor, G. S. Hilton, A. R. Nix, and J. P. McGeehan, "Impact of antenna pattern and handset rotation on macro-cell and pico-cell propagation in heterogeneous LTE networks," Proceedings of the 2012 IEEE International Symposium on Antennas and Propagation, 1-2, Jul. 2012.

12. Harrysson, F., J. Medbo, A. F. Molisch, A. J. Johansson, and F. Tufvesson, "Efficient experimental evaluation of a MIMO handset with user influence," IEEE Trans. Wirel. Commun., Vol. 9, No. 2, 853-863, Feb. 2010.
doi:10.1109/TWC.2010.02.090588

13. Buris, N. E., M. Abdul-Gaffoor, and E. Krenz, "Capacity based MIMO antenna design," 2017 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, 1695-1696, Jul. 2017.

14. Dao, M.-T., V.-A. Nguyen, Y.-T. Im, S.-O. Park, and G. Yoon, "3D polarized channel modeling and performance comparison of MIMO antenna configurations with different polarizations," IEEE Trans. Antennas Propag., Vol. 59, No. 7, 2672-2682, Jul. 2011.
doi:10.1109/TAP.2011.2152319

15. Razavi, A., A. A. Glazunov, P. S. Kildal, and J. Yang, "Characterizing polarization-MIMO antennas in Random-LOS propagation channels," IEEE Access, 2016.

16. Razavi, A. and A. A. Glazunov, "Probability of detection functions of polarization-MIMO systems in Random-LOS," IEEE Access, 2017.

17. Soltani, M. D., A. A. Purwita, Z. Zeng, H. Haas, and M. Safari, "Modeling the random orientation of mobile devices: Measurement, analysis and LiFi use case," IEEE Trans. Commun., 2019.

18. Watthanapak, W., A. Namahoot, and S. Chalermwisutkul, "Effects of reader antenna orientation on received signal strength of UHF RFID tags for handheld reader localization," 2019 Research, Invention, and Innovation Congress (RI2C), 1-4, Dec. 2019.

19. Lehne, P. H., A. A. Glazunov, K. Mahmood, and P.-S. Kildal, "Analyzing smart phones’ 3D accelerometer measurements to identify typical usage positions in voice mode," 2016 10th European Conference on Antennas and Propagation (EuCAP), 1-5, Apr. 2016.

20. Blum, J. R., D. G. Greencorn, and J. R. Cooperstock, Smartphone Sensor Reliability for Augmented Reality Applications, 127-138, Springer, Berlin, 2013.

21. Incel, O., "Analysis of movement, orientation and rotation-based sensing for phone placement recognition," Sensors, Vol. 15, No. 10, 25474-25506, Oct. 2015.
doi:10.3390/s151025474

22. Amiri Sani, A., L. Zhong, and A. Sabharwal, "Directional antenna diversity for mobile devices," Proceedings of the Sixteenth Annual International Conference on Mobile Computing and Networking — MobiCom’10, 221, 2010.
doi:10.1145/1859995.1860021

23. Dehghani Soltani, M., X. Wu, M. Safari, and H. Haas, "Access point selection in Li-Fi cellular networks with arbitrary receiver orientation," 2016 IEEE 27th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 1-6, Sep. 2016.

24. Razavi, A., A. A. Glazunov, P. Kildal, and J. Yang, "Investigation of polarization deficiencies in SIMO systems in Random-LOS propagation channels," 2015 International Symposium on Antennas and Propagation (ISAP), Vol. 1, 1-3, 2015.

25. Jazar, R. N., Theory of Applied Robotics, Springer, 2007.
doi:10.1007/978-0-387-68964-7

26. Brown, C. E., "Coefficient of variation," Applied Multivariate Statistics in Geohydrology and Related Sciences, 155-157, Springer Berlin Heidelberg, Berlin, Heidelberg, 1998.

27. Chen, Z. N., Antennas for Portable Devices, John Wiley & Sons, Ltd, 2007.
doi:10.1002/9780470319642

28. Rabinovich, V., N. Alexandrov, and B. Alkhateeb, Automotive Antenna Design and Applications, CRC Press, 2017.
doi:10.1201/9781439804094

29. Liang, Z. X., et al., "Improved hybrid leapfrog ADI-FDTD method for simulating near-field coupling effects among multiple thin wire monopole antennas on a complex platform," IEEE Trans. Electromagn. Compat., 2017.

30. Zhang, Z., Antenna Design for Mobile Devices, 2nd Ed., John Wiley & Sons (Asia) Pte Ltd, 2017.
doi:10.1002/9781119132332

31. NEBENS "MIMObit,", http://www.nebens.com, 2018.

32. CST MICROWAVE STUDIO "CST MICROWAVE STUDIO,", https://www.cst.com, 2018.

33. Singh, H. S., G. K. Pandey, P. K. Bharti, and M. K. Meshram, "A compact dual band MIMO/diversity antenna for WLAN applications," 2013 Students Conference on Engineering and Systems (SCES), 1-5, Apr. 2013.

34. Biswal, S. P. and S. Das, "Two-element printed PIFA-MIMO antenna system for WiMAX and WLAN applications," IET Microwaves, Antennas Propag., Vol. 12, No. 14, 2262-2270, Nov. 2018.
doi:10.1049/iet-map.2018.5271

35. Biswal, S. P. and S. Das, "A dual band MIMO PIFA for WLAN application," 2017 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), 121-122, Jul. 2017.

36. Chattha, H. T., M. Nasir, Q. H. Abbasi, Y. Huang, and S. S. AlJa’afreh, "Compact low-profile dual-port single wideband planar inverted-F MIMO antenna," IEEE Antennas Wirel. Propag. Lett., Vol. 12, 1673-1675, 2013.
doi:10.1109/LAWP.2013.2293765

37. Singh, A., S. K. Dash, and V. R. Gupta, "Dual feed planar inverted-F antenna for MIMO application," 2017 Innovations in Power and Advanced Computing Technologies (i-PACT), 1-4, Apr. 2017.

38. Al-Wahhamy, A., H. Al-Rizzo, and N. E. Buris, "On the modeling of antenna arrays for massive MIMO systems," 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, 1565-1566, Jul. 2018.

39. Estrada, J. H., E. A. Cano-Plata, C. Younes-Velosa, and C. L. Cortes, "Entropy and coefficient of variation (CV) as tools for assessing power quality," Ing. e Investig., 2011.

40. Krishnamoorthy, K., Handbook of Statistical Distributions with Applications, Chapman and Hall/CRC, 2016.
doi:10.1201/b19191

41. Sammarco, P. W., A.Winter, and J. C. Stewart, "Coefficient of variation of Sea Surface Temperature (SST) as an indicator of coral bleaching," Mar. Biol., Vol. 149, No. 6, 1337-1344, Sep. 2006.
doi:10.1007/s00227-006-0318-0

42. Shechtman, O., The Coefficient of Variation as an Index of Measurement Reliability, 39-49, Springer, 2013.

Dr. Abbas Al-Wahhamy

Prof. Hussain M. Al-Rizzo

Dr. Nicholas E. Buris