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Near Site Outdoor Channel Measurement and Optimization Processing

Lukas Klozar
Department of Radio Electronics, Brno University of Technology, Purkyova 118, 612 00 Brno, Czech Republic E-mail: xkloza00@stud.feec.vutbr.cz

Abstract This poster deals with a multislope propagation channel model optimization for a near site of a transmitter in mobile communication networks. The PSO processing, of pathloss model parameters, with a criterial function based on the MSE deviation error estimation, is described.
Keywords Propagation channel, model, multislope, path loss, PSO.
1 30

M u lti s lo p e L o g D is ta n c e p ro p a g a tio n m o d e l

The multislope modeling approach is applied to simulate the higher level attenuation in near site of a transmitter. Two Coupling points, at distance 40m and 1 km define the boundaries of the simulation space. Between them the PSO processing model the parameters of a channel to the best fit with measurred data. The MSE decision technique in criteria function of PSO is applied.

P a t h lo s s [d B ]

Simulation Introduction

1 20 1 10 1 00 90 80 70 60 10
2

10

D is t a n c e [m ]

Propagation Channel Modeling


The path loss levels of Coupling points are predicted according to the Freespace propagation (40 m ~ 63dB) and Okumura-Hata prediction (1 km ~ 127 dB). Each agent of the PSO represents the breakpoint in the work space. Position of this breakpoint changes the slope n of the model. Path losses of this model PLP are compared with measured data PLM, to find one with a minimal deviation value of the MSE.
PL=10nlog10 d
MSE =
P a t h lo s s [d B ]

Fig. 1 Multislope modeling principle with one optimised breakpoint and two coupling points.
M u lti s lo p e L o g D is ta n c e p ro p a g a tio n m o d e l
1 30 1 20 1 10 1 00 90 80 70

PLM PLP 2
N1

60 10

10

D is t a n c e [m ]

Two approaches are simulated, one with single optomized breakpoint ( seeL Fig. 1 ), and another with two breakpoints =32.4420log f 20log d ( see Fig. 2).
fs 10 10

Fig. 2 Multislope modeling principle with two optimised breakpoints and two coupling points.
MSE [dB] Breakpoint distance of transmitter [m] 1.BP 41 135 41 122 2.BP 673 990 997 818 Breakpoint path loss level [dB] 1.BP 90 103 100 101 2.BP 108 110 108 111

Conclusion
The results of the modeling simulations are shown in table Tab.1 and Tab. 2. The deviation error is caused by fading effects. These affects signal propagation and causes a path loss level variation.

MSE deviation error [dB] 15.5 15.4 15.4 15.3 15.3

Breakpoint distance of transmitter [m] 192 137 947 115 106

Breakpoint path loss level [dB] 99 95 120 91 90

x 13.0 12.7 12.2 13.1

Tab. 1 Model MSE deviations for one optimised breakpoint.

Tab. 2 Model MSE deviations for two optimised breakpoint.

Acknowledgements
Thanks to prof. Dr. Ing. Z. Kolka. This paper was supported by the European Community's Seventh Framework program (FP7/2007-2013) under grant agreement no. 230126.

IEEE Workshop Vsack Cb, 08/2011

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