COST 286 Electromagnetic Compatibility (EMC) in Diffused Communication Systems Hamburg, 25th-26th November, 2004 Wroclaw University of Technology Institute of Telecommunications and Acoustics Wybrzeże Wyspiańskiego 27, Wrocław Poland Research on simulating radiowave propagation in closed environments Kamil Staniec

Technological congestion 1 /21

b g (interference) a b/g (no interference) 3.Bluetooth b/g (interference) Current measurements – mixed configurations 2 /21

Existing indoor propagation models 1. Statistical models: 1.1 Amplitude distribution 1.2 Phase distribution 1.3 Angle-of-arrival distribution 2. Empirical models 2.1 ITU-R P.1238: 2.2 Multilayer model: FAF = 15+(5  10)*k [dB] 3 /21

Indoor propagation effects 4 /21 [modified 3]

Multipath propagation 5 /21

Advantages of using ray tracing method: imitates radiowave propagation 6 /21

7 /21 patterns drawn with 642 rays Advantages of using ray tracing method: easy generation of any antenna patterns

8 /21 Advantages of using ray tracing method: radio channel power delay time profile

Indoor propagation – challenges to be solved Common assumptions in existing RT model: constant wall attentuation (irrespective of material electric parameters) walls/partitions perfectly thin presence of objects/persons not considered 9 /21

Research – our objectives Create exact analytical model that includes: persons/objects „thick” walls variable attenuation of partitions radio channel time-dispersion characteristics 10 /21

X-section of a partition wall 11 /21

Multilayer structure – influence of innacurate electric parameters 12 /21

Multilayer structure – wall attenuation vs. incidence angle 13 /21

Multilayer structure – EM wave attenuation vs. frequency 14 /21

Infinite thinnessActual thickness Thick / thin walls modeling 15 /21

Analytical calculation of multilayer wall attenuation 16 /21

Thick walls with persons (yellow) and objects (green) 17 /21 Simulated environment (example)

Optimisation 1: Environment prescanning 18 /21

Optimisation 2: look-up table in variable attenuation calculations 19 /21

Environment database preprocessing accomplished: available modes: perfectly thin walls actually thick walls inclusion of persons inclusion of furniture variable walls attenuation w/r to frequency, incidence angle, polarization (database storage) Preliminary ray tracing for „full” ray tracing optimisation purposes (av. 95% time saving) 20 /21 State of research:

e-field distribution maps in a closed environment (SOHO, vehicles, railway tunnels) information on radio channel dispersiveness - Power Delay Profile /available for each pixel/ modeling mutual AP’s interference 21 /21 Possible applications:

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