Relationship Between the Path Loss Exponent and the Room Absorption for Line-of-Sight Communication
Keywords:
Relationship Between the Path Loss Exponent and the Room Absorption for Line-of-Sight CommunicationAbstract
In indoor propagation, the log-distance path loss model represents the received power as declining with distance from the transmitter according to1/ r n , where r is the straight-line distance from the transmitter to the receiver. Previously, the value of the path loss exponent n has been derived from measured received signal strengths at a specific site. In this paper, the value of n is estimated from the geometry of the room and the electrical properties of the walls. Using the Sabine model, these determine the room absorption and hence the received power as a function of distance from the transmitter. Then, a least-square-error curve fit of the logdistance path loss model to the Sabine model determines the value of n . The electric field strength in a typical rectangular room is compared using ray tracing, the Sabine model, and the path loss model. Then the value of the path loss exponent is presented as a function of the power absorption coefficient of the walls, floor and ceiling of the room, for a typical ceiling height. Evaluating n from analytic information rather than from measurement enhances the usefulness of the path loss model in simulations of the coverage of antennas for the design of wireless local area network installations at specific sites.
Downloads
References
H. Hashemi, “The indoor propagation channel,”
Proc. IEEE, vol. 81, no. 7, pp. 943-968, July 1993.
R. A. Valenzuela, O. Landron, and D. L. Jacobs,
“Estimating local mean signal strength of indoor
multipath propagation,” IEEE Trans. on Vehicular
Technology, vol. 46, no. 1, pp. 203- 212, Feb. 1997.
R. A. Valenzuela, O. Landron, and D. L. Jacobs,
“Estimating local mean signal strength of indoor
multipath propagation,” IEEE Trans. on Veh. Tech ,
vol. 46, no. 1, pp. 203-212, Feb. 1997.
H. Bertoni, W. Honcharenko, L. R. Maciel, and H.
H. Xia, “UHF propagation prediction for wireless
personal communications,” Proc. IEEE, vol. 82, no.
, pp. 1333-1359, Sept. 1994.
T. S. Rappaport, Wireless Communications
Principles and Practice, 2 nd edition. New Jersey:
Prentice Hall PRT, 2002.
K. W. Cheung, J. H. M. Sau, and R. D. Murch, “A
new empirical model for indoor propagation
prediction,” IEEE Trans. on Veh. Tech., vol. 47, no.
, pp. 996-1001, Aug. 1998.
D. Lee, M. J. Neve, and K. W. Sowerby, “The
impact of structural shielding on the performance of
wireless systems in a single floor office building,”
IEEE Trans. on Wireless Comm., vol. 6, no. 5, pp.
-1795, May 2007.
D. A. Hill, “A reflectio n coefficient derivation for
the Q of a reverberation chamber,” IEEE Trans. on
EMC, vol. 38, no. 4, pp. 591-592, Nov. 1992.
C. L. Holloway, D. A. Hill, J. M. Ladbury, and G.
Koepke, “Requirements for an effective
reverberation chamber: loaded or unloaded,” IEEE
Trans. on EMC , vol. 48, no. 1, pp. 187-194, Feb.
C. L. Holloway, M. G. Cotton, and P. McKenna, “A
model for predicting the power delay profile
characteristics in a room,” IEEE Trans. on Veh.
Tech., vol. 48, no. 4, pp. 1110-1120, July 1999.
C. W. Trueman, S. S. Muhlen, D. Davis, and B.
Segal, “Field strength estimation in indoor
propagation by the Sabine method,” in Proceedings
of the 24th Annual Review of Progress in Applied
Computational Electromagnetics. Niagara Falls,
Ontario, Canada: ACES 2008, pp. 876-881.
C. W. Trueman, D. Davis, B. Segal, and W. Muneer,
“Validation of fast site-specific mean-value models
for indoor propagation,” to be published in the
Applied Computational Electromagnetics Society
Journal, April 2009.
J. B. Andersen, J. O. Nielsen, G. F. Pedersen, G.
Bauch, and M. Herdin, “Room electromagnetics,”
IEEE Ant. and Prop. Mag . vol. 49, no. 2, pp. 27-33,
April 2007
