Blackboard Notes
Theoretical Evidence
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saunders07wireless: 9.3
Summarized
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schwarz04wireless: 2.2 “shadow fading”
P
rdBm
d [m]
average received power due to path loss
• described by log-distance path loss model
• just depends on transmitter receiver separation
• called area mean
average received power when taking shadow fading into account
• called local mean
• depends on actual transmitter and receiver position
• however does not change rapidly when node positions are changed slightly
• variation typically in the order of many wavelengths
• decribed by log-normal shadowing model for an arbitrary transmitter receiver pair
This is called large-scale fading, slow fading, shadow fading or log-normal fading
Correlated Shadowing
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Motivation
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frey
When used in a Simulation:
For arbitrary non related transmitter receiver pairs.
Use log-normal shadowing model to generate average received power (i.e. local mean) for each pair
• compute the area mean from log-distance path loss model
• add independent Gaussian random value with mean zero and variance and variance σ
• (or just generate independent Gaussian value with mean set to area mean and variance σ) Be careful if transmitter receiver pairs t1,r1 and t2,r2 are statistically dependent!
The Gaussian values are no longer independent! (due to slow fading) see the
following discussion
Blackboard Notes
Motivation
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frey
Blackboard Notes
Correlated Shadowing Models
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saunders07wireless: 9.6
Blackboard Notes
Serial Correlation
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saunders07wireless: 9.6.1
Blackboard Notes
Serial Correlation
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saunders07wireless: 9.6.1
Blackboard Notes
How to generate two correlated Gaussian distributed random variables?
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Blackboard Notes
Simulating a whole correlated shadowing process…
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saunders07wireless: 9.6.1
Example Plot
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saunders07wireless: 9.6.1
Image source: Saunders, S., & Aragón-Zavala, A. (2007). Antennas and Propagation for Wireless Communication Systems (2nd Edition). Wiley (Fig. 9.14)
Blackboard Notes
Site‐to‐Site Correlation
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saunders07wireless: 9.6.2
Blackboard Notes
Site‐to‐Site Correlation
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saunders07wireless: 9.6.2
Blackboard Notes
Site‐to‐Site Correlation
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saunders07wireless: 9.6.2
Blackboard Notes
Site‐to‐Site Correlation
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saunders07wireless: 9.6.2
Blackboard Notes
Adapting Serial Correlation to two Mobile Nodes
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agrawal09correlated‐twc: III.A