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PropagationLoss Prediction Using Ray Tracing with a RandomPhase Technique
Satoshi TAKAHASHI Yoshihide YAMADA
Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Vol.E81A
No.7
pp.14451451 Publication Date: 1998/07/25
Online ISSN:
DOI:
Print ISSN: 09168508 Type of Manuscript: Special Section PAPER (Special Section on Fundamentals of Multidimensional Mobile Information Network) Category: Keyword: radio propagation, propagationloss prediction, ray tracing, randomphase technique, probabilitybased cell design,
Full Text: PDF(652.5KB)>>
Summary:
For mobile telecommunication systems, it is important to accurately predict the propagationpath loss in terms of the estimation of the radiowave coverage area. The propagationpath loss has been estimated in a median obtained spatially from many received amplitudes (envelopes) within a region of several tens times as long as the wavelength, rather than in the envelopes themselves. Although ray tracing can obtain the envelopes and their median that reflect the sitedependent characteristics, the estimated median sometimes does not agree with the measured one. Therefore, the accuracy improvement has been expected. In this paper, an accuracy improvement is achieved by substituting a median with random phases for the median obtained spatially from many envelopes. The characteristic function method is used to obtain the cumulative distribution function and the median analytically where the phases are randomized. In a multipath environment, the phaseestimation error accompanying the location error of the ray tracing input influences the spatially obtained median. The phaserandomizing operation reduces the effects of the phaseestimation error on the median prediction. According to our estimation, improvements in accuracy of 4. 9 dB for the maximum prediction error and 2. 9 dB for the RMS prediction error were achieved. In addition, a probabilitybased celldesign method that takes the radiowave arrival probability and the interference probability into consideration is possible by using the percentiles obtained by the characteristic function method and the celldesign examples are shown in this paper.

