volume | PIER Journals

Abstract

The average downlink data-rate in massive Multiple Input Multiple Output (MIMO) networks within realistic urban environments is characterized by means of ray-tracing simulations. The links between the receivers and transmitters are mostly established through rooftop propagation, which requires special treatment due to multiple diffractions near the optical boundaries. The bidirectional ray-tracing method is utilized in order to simulate these effects accurately. The average downlink data-rate is also calculated according to an empirical rooftop propagation model and the differences as well as the similarities with the bidirectional ray-tracing results are demonstrated. Additionally, an iterative Shooting and Bouncing Rays (SBR) algorithm, which improves the computational efficiency of the bidirectional ray-tracing, is introduced. The algorithm aims to maximize the number of rays, which contribute to the result, by setting specific launch directions. The results show that noticeable improvements in the computation time are possible.

1. Fukuda, H., T. Nishimura, Y. Ogawa, and T. Ohgane, "Performance evaluation of full-dimension MIMO in indoor line-of-sight environments," IEEE Wireless Communications and Networking Conference (WCNC), 159-164, Gran Canaria, Spain, 2015.
doi:10.1109/WCNC.2015.7127462 Google Scholar

2. Ling, H., R. Chou, and S. Lee, "Shooting and bouncing rays: calculating the RCS of an arbitrarily shaped cavity," IEEE Transactions on Antennas and Propagation, Vol. 37, No. 2, 194-205, 1989.
doi:10.1109/8.18706 Google Scholar

3. Kouyoumjian, R. and P. 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/PROC.1974.9651 Google Scholar

4. Holm, P. D., "UTD diffraction coefficients for higher order wedge diffracted fields," IEEE Transactions on Antennas and Propagation, Vol. 44, No. 6, 879-888, 1996.
doi:10.1109/8.509892 Google Scholar

5. 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:10.1109/8.14401 Google Scholar

6. Kanatas, A. G., I. D. Kountouris, G. B. Kostaras, and P. Constantinou, "A UTD propagation model in urban microcellular environments," IEEE Transactions on Vehicular Technology, Vol. 46, No. 1, 185-193, 1997.
doi:10.1109/25.554751 Google Scholar

7. Taygur, M. M., I. O. Sukharevsky, and T. F. Eibert, "Computation of antenna transfer functions with a bidirectional ray-tracing algorithm utilizing antenna reciprocity," URSI Atlantic Radio Science Conference (AT-RASC), Gran Canaria, Spain, 2018. Google Scholar

8. Taygur, M. M., I. O. Sukharevsky, and T. F. Eibert, "A bidirectional ray-tracing method for antenna coupling evaluation based on the reciprocity theorem," IEEE Transactions on Antennas and Propagation, Vol. 66, No. 12, 6654-6664, 2018.
doi:10.1109/TAP.2018.2876680 Google Scholar

9. Collin, R. and F. Zucker, Antenna Theory, McGraw-Hill, New York, NY, 1969.

10. Sukharevsky, O., Electromagnetic Wave Scattering by Aerial and Ground Radar Objects, CRC Press Inc., Boca Raton, FL, 2014.
doi:10.1201/b17239

11. Gamkrelidze, R. V., Analysis I: Integral Representations and Asymptotic Methods, Springer, Berlin, 2011.

12. Xu, F. and Y.-Q. Jin, "Bidirectional analytic ray tracing for fast computation of composite scattering from electric large target over a randomly rough surface," IEEE Transactions on Antennas and Propagation, Vol. 57, No. 5, 1495-1505, 2009.
doi:10.1109/TAP.2009.2016691 Google Scholar

13. Mocker, M. S., M. Schiller, R. Brem, Z. Sun, H. Tazi, T. F. Eibert, and A. Knoll, "Combination of a full-wave method and ray tracing for radiation pattern simulations of antennas on vehicle roofs," European Conference on Antennas and Propagation (EuCAP), Lisbon, Portugal, 2015. Google Scholar

14. Schiller, M., A. Knoll, M. S. Mocker, and T. F. Eibert, "GPU accelerated ray launching for highfidelity virtual test drives of VANET applications," Conference on High Performance Computing & Simulation (HPCS), Amsterdam, Netherlands, 2015. Google Scholar

15. Brem, R. and T. F. Eibert, "A shooting and bouncing ray (SBR) modeling framework involving dielectrics and perfect conductors," IEEE Transactions on Antennas and Propagation, Vol. 63, No. 8, 3599-3609, 2015.
doi:10.1109/TAP.2015.2438318 Google Scholar

16. Brem, R. and T. F. Eibert, "Multi-radiation center transmitter models for ray tracing," IEEE Transactions on Antennas and Propagation, Vol. 60, No. 7, 3382-3388, 2012.
doi:10.1109/TAP.2012.2196956 Google Scholar

17. Yun, Z. and M. Iskander, "Ray tracing for radio propagation modeling: principles and applications," IEEE Access, Vol. 3, 1089-1100, 2015.
doi:10.1109/ACCESS.2015.2453991 Google Scholar

18. Shi, D., N. Lv, N. Wang, and Y. Gao, "An improved shooting and bouncing ray method for outdoor wave propagation prediction," ACES Journal, Vol. 32, No. 7, 581-585, 2017. Google Scholar

19. Wong, R., Asymptotic Approximations of Integrals, SIAM, Philadelphia, PA, 2001.
doi:10.1137/1.9780898719260

20. Vogler, L. E., "An attenuation function for multiple knife edge diffraction," Radio Science, Vol. 17, No. 6, 1541-1546, 1982.
doi:10.1029/RS017i006p01541 Google Scholar

21. International Telecommunications Union "Recommendation ITU-R P1411-9: Propagation data and prediction methods for the planning of short rnage outdoor radio communication systems and radio local area networks in the frequency range 300MHz to 100 GHz,", Report, 2017. Google Scholar

Mr. Mehmet Mert Taygur

Dr. Ilya O. Sukharevsky

Dr. Thomas F. Eibert