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COST 286 Electromagnetic Compatibility (EMC) in Diffused Communication Systems Hamburg , 25th-26th November, 2004. Research on simulating radiowave propagation in closed environments. Kamil Staniec. Wroclaw University of Technology Institute of Telecommunication s and Acoustics
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COST 286 Electromagnetic Compatibility (EMC) in Diffused Communication Systems Hamburg, 25th-26th November, 2004 Research on simulating radiowave propagation in closed environments Kamil Staniec Wroclaw University of Technology Institute of Telecommunications and Acoustics Wybrzeże Wyspiańskiego 27, 50-370 Wrocław Poland e-mail: kamil.staniec@pwr.wroc.pl
Current measurements – mixed configurations • 802.11b - 802.11g (interference) • 802.11a - 802.11b/g (no interference) • Bluetooth - 802.11b/g (interference) 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+(510)*k [dB] 3/21
Indoor propagation effects 4/21 [modified 3]
Advantages of using ray tracing method: imitates radiowave propagation 6/21
Advantages of using ray tracing method: easy generation of any antenna patterns patterns drawn with 642 rays 7/21
Advantages of using ray tracing method: radio channel power delay time profile 8/21
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
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
Simulated environment (example) Thick walls with persons (yellow) andobjects (green) 17/21
Optimisation 1: Environment prescanning 18/21
Optimisation 2: look-up table in variable attenuation calculations 19/21
State of research: • 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
Possible applications: • 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