uniform geometrical theory of diffraction (user body shadowing)
TRANSCRIPT
RadioTechnology LabSeoul National University
[ ]The Modeling of User Body Shadowing based on the UTD
Radio Technology Lab (prof. C.H. Kim)
Kim Changhoe
INDEX
1. Introduction
2. UTD Model
3. Experiment Model
4. Result of UTD & Experiment Model
5. Conclusion
RadioTechnology Lab
Seoul National University
RadioTechnology Lab
Seoul National University
RT
L
adioechnology
aboratory1. Introduction (1/2)
2014-11-06 3
Shadowing Effect Shadowing effect means the phenomenon that obstacle including building or
mountain attenuates the received signal power
Important when we model the channel
Human & wave propagation Human is the nearest obstacle of the mobile (receiver)
Human can disturb wave propagation in indoor environment
RadioTechnology Lab
Seoul National University
RT
L
adioechnology
aboratory1. Introduction – Problem set (2/2)
2014-11-06 4
What is the Problem ? Shadowing effect by user (specially, in a indoor environment)
Reflection, diffraction should be considered
How can We Solve ?
UTD Exact calculation
Body shadowing
effect
RadioTechnology Lab
Seoul National University
RT
L
adioechnology
aboratory2. UTD Model (1/4)
2014-11-06 5
UTD (Uniform Geometrical Theory of Diffraction)Effective method for analyzing diffraction of material
We can obtain numerical analysis values
Three types of diffraction situation (Scattering, Radiation, Coupling)
Scattering Radiation Coupling
Stick to
materialX Only Rx or Tx Tx & Rx
Concept
Figure
Tx
Rx
material
TxRx
TxRx
material material
Model
Contents
RadioTechnology Lab
Seoul National University
RT
L
adioechnology
aboratory2. UTD Model (2/4)
2014-11-06 6
Lit Zone LOS(Line-of-Sight) component
Dependent on the distance mainly
Shadow ZoneNLOS(non-LOS) component
Including the distance, material and diffraction effect should be involved
RadioTechnology Lab
Seoul National University
RT
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adioechnology
aboratory2. UTD Model – Scattering (3/4)
2014-11-06 7
When Rx is in Lit zone,
𝑬𝟎 = E-field of LOS component
R = UTD reflection coefficient, L = distance coefficient
When Rx is in Shadow zone,
E1, E2 = E field at Q1’, Q2’ respectively
T1, T2 = UTD diffraction coefficient (Q1’-Q1, Q2’-Q2)
𝑬𝑺,𝑳𝑶𝑺 = 𝑬𝟎𝑹𝑳𝒅𝒆−𝒋𝒌𝒔𝑺𝟏 + 𝑬𝟎
𝑬𝑺,𝑵𝑳𝑶𝑺 = 𝑬𝟏𝑻𝟏𝒆−𝒋𝒌𝒔𝑺𝟐
√𝒔𝑺𝟐+ 𝑬𝟐𝑻𝟐
𝒆−𝒋𝒌𝒔𝑺𝟑
√𝒔𝑺𝟑
RadioTechnology Lab
Seoul National University
RT
L
adioechnology
aboratory2. UTD Model – Radiation (4/4)
2014-11-06 8
When Rx is in Lit zone,
𝑯𝟏 = Radiaton Coefficient in Lit zone
𝑪𝟎 = propotional factor, 𝜽𝒍 = angle between LOS line and normal line of Rx
When Rx is in Shadow zone,
𝑯𝟐=Radiation coefficient in Shadow zone
𝑡1, 𝑡2= arc length respectively Q3-Rx and Q4-Rx
𝑬𝑹,𝑳𝑶𝑺 = 𝑪𝟎𝑯𝟏 𝒄𝒐𝒔𝜽𝒍𝒆−𝒋𝒌𝒔𝑹𝟏
√𝒔𝑹𝟏
𝑬𝑹,𝑵𝑳𝑶𝑺 = 𝑪𝟎𝑯𝟐[𝒆−𝒋𝒌𝒕𝟏
𝒆−𝒋𝒌𝒔𝑹𝟐
𝒔𝑹𝟐+𝒆−𝒋𝒌𝒕𝟐
𝒆−𝒋𝒌𝒔𝑹𝟑
𝒔𝑹𝟑]
RadioTechnology Lab
Seoul National University
RT
L
adioechnology
aboratory3. Experiment Model
2014-11-06 9
Experiment Model The power of received signal is measured
Rx moved from 𝜽 = 𝟎° to 𝜽 = 𝟑𝟔𝟎° at intervals of 10°
Frequency of the signal is 2.4GHz
Chest
Model
Head
Model
Rx-User
(d)15cm 2cm
Antenna
Height
(Rx)
140cm 170cm
RadioTechnology Lab
Seoul National University
RT
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adioechnology
aboratory4. Result – Chest Model (1/2)
2014-11-06 10
Received PowerMeasurement pattern is similar with the scattering model
Scattering model and data dependent on LOS and reflection component from 𝜽 = 𝟎° to SSB angle
Deep fades exist
RadioTechnology Lab
Seoul National University
RT
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adioechnology
aboratory4. Result – Head Model (2/2)
2014-11-06 11
Received PowerAlso similar pattern with Scattering Model
Scattering Model and data dependent on LOS and reflection component from 𝜽 = 𝟎° to SSB
RadioTechnology Lab
Seoul National University
RT
L
adioechnology
aboratory5. Conclusion
2014-11-06 12
UTD SimulationUser shadowing effect can be solved by UTD Scattering or Radiation
Model
Experiment data is similar with Scattering model for chest model and head model the pattern of received power
Future WorkExperiments based on the motion of user
Another band frequency (for indoor)
RadioTechnology Lab
Seoul National University
RT
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adioechnology
aboratoryReference
2014-11-06 13
[1] Kim Changhoe, Jung jaehoon, Kim Seongchul, “A Study on the Modeling of User Body Shadowing based on the UTD”, in Proc. KICS Int, Conf Commun, Jeju, Korea, June, 2014
[2] J. H. Jung, J. H. Choi, Y.H. Kim and C.H. Kim, “A Study on the User-Shadowing based on the Ray-tracing”, in Proc. KICS Int, Conf Commun, pp. 247-248, Pyeongchang, Korea, Jan, 2014
[3] D.A. Mcnamara, C.W. Pistorius, and J.A. Malherbe, “Introduction to the Uniform Geometrical Theory of Diffraction”, Boston, MA: Artech House, 1990.