A RAY TRACING TECHNIQUE FOR COVERAGE PREDICTIONS IN MICRO CELLULAR ENVIRONMENTS

M. E. C. Rodrigues, L. A. R. Ramirez, L. A. R. Silva Mello, F. J. V. Hasselmann

Abstract


This work presents a 3D vector formulation for calculation of the field scattered by finite conductivity wedges, developed as an extension of the Uniform Theory of Diffraction (UTD) version for perfect conductors, representative of obstacles usually encountered in both indoor and outdoor environments served by cellular communication systems. Its main contribution consists, aside from the 3D vector treatment for the problem at hand, of the definition of diffraction coefficient parameters associated to virtual reflections on the wedge shadowed face. The singular behavior of diffraction coefficients thus obtained, along regions coincident with (real and virtual) geometrical shadow boundaries, as well as the resulting reciprocity of the formulation in terms of the arbitrary choice of the wedge illuminated face, indicate its adequacy. The formulation is next applied to the calculation of propagation path losses and delay profiles for typical building layouts. Implementation aspects of launching, tracing and capturing relevant optical rays as well as applying the Quadtree method for spatial (scenario) discrimination are also discussed.

Full Text:

PDF

References


R. G. Kouyoumjian and P. H. Pathak, A uniform geometrical theory of diffraction for an edge in a perfectly conducting surface, Proceedings of the IEEE, Vol. 62, 1974, pp. 1448-1461.

G. D. Maliuzhinets, Excitation, reflection and emission of of surface waves from wedges of given face impedances, Soviet Phys. Doklady, Vol. 3, 1958, pp. 752-755.

G. D. Maliuzhinets, Inversion formula for the Sommerfeld integral, Soviet Phys. Doklady, Vol. 3, 1958, pp. 52-56.

T. B. A. Senior and J. L. Volakis, Approximate boundary conditions in electromagnetics, IEE Electromagnetic Waves Series 41, 1995, Ch. 4.

M. Aïdi and J. Lavergnat, Comparison of Luebbers´ and Maliuzhinets´ wedge diffraction coefficients in urban channel modeling, in Progress in Electromagnetics Research, PIER 33, 2001, pp. 1-28.

R. J. Luebbers, A heuristic UTD slope diffraction coefficient for rough lossy wedges, IEEE Trans. Antennas Propagat., Vol. AP-37, 1989, pp. 206-211.

M. F. Cátedra and J. Pérez-Arriaga, Cell planning for wireless communications, Artech House – Mobile Communications Series, 1999.

D. A. McNamara, C. W. I. Pistorius and J. A. G. Malherbe, Introduction to the uniform geometrical theory of diffraction, Artech House, 1990, pp. 185-188.

M. E. C. Rodrigues, 3D ray tracing techniques for field calculation in indoor and outdoor environments, M. Sc. Thesis, EE Dept., PUC/Rio, 2000, in Portuguese.

L.A.R. Ramirez, Técnica de Lançamento de Raios em Três Dimensões para a Previsão de Cobertura em Ambientes Micro-celulares, M. Sc. Thesis, EE Dept., PUC/Rio, 2002, in Portuguese.

http://www.opengl.org

D. J. Cichon, T. C. Becker and M. Döttling, Ray optical prediction of outdoor and indoor coverage in urban macro and micro-cells, in IEEE VTS 46th Vehicular Technology Conference, Atlanta GA, Vol. 1, 1996, pp. 41-45.

B. E. Gschwendtner and F. M. Lanstorfer, 3-D Propagation modeling in microcell including terrain effects, in 6th IEEE Symposium on PIMRC, Vol. 2, 1995, pp 532-536.

M. G. Sánchez, L. de Haro, A. G. Pino and M. Calvo, Exhaustive ray tracing algorithm for microcellular propagation prediction models, IEE Electronics Letters, vol. 32, No. 7, 1996, pp. 624-625.

S. Y. Tan and H. S. Tan, Propagation model for microcellular communication applied to path loss measurements in Ottawa city streets, IEEE Transactions on Vehicular Technologies, Vol.44, No. 2, 1995, pp. 313-316..

D. J. Cichon, T. Zwick and J. Lähteenmäki, Ray optical indoor modeling in multifloored buildings: simulations and measurements, in IEEE Antennas and Propagation Society International Symposium Digest, vol. 1, 1995, pp. 522-525.

G. Durgin, N. Patwari and T. S. Rappaport, Improved 3D ray launching method for wireless propagation prediction, IEE Electronics Letters, Vol. 33, No. 16, 1997, pp. 1412-1413.

K. R. Schaubach, N. J. Davis and T. Rappaport, A ray tracing method for predicting path loss and delay spread in microcellular enviorements, IEEE 42nd Vehicular Technology Conference, Denver CO, vol. 2, 1992, pp. 932-935.

W. Honcharenko, H. L. Bertoni, J. L. Dailing, J. Qian and H. D. Yee, Mechanics governing UHF propagation on single floors in modern office buildings, IEEE Transactions on Vehicular Technology, vol. 41, no. 4, 1992, pp. 496-504.


Refbacks

  • There are currently no refbacks.


© Copyright 2007-2016 JMOe Brazilian Microwave and Optoelectronics Society (SBMO) and Brazilian Society of Electromagnetism (SBMag)