Blackboard Notes
Two‐Ray Ground Reflection Model
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 63
schwarz04wireless: 2.2 “Path‐loss: two‐ray model”
Blackboard Notes
Two‐Ray Ground Reflection Model
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 64
schwarz04wireless: 2.2 “Path‐loss: two‐ray model”
Blackboard Notes
Two‐Ray Ground Reflection Model
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 65
schwarz04wireless: 2.2 “Path‐loss: two‐ray model”
Blackboard Notes
Two‐Ray Ground Reflection Model
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 66
schwarz04wireless: 2.2 “Path‐loss: two‐ray model”
Blackboard Notes
Two‐Ray Ground Reflection Model
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 67
schwarz04wireless: 2.2 “Path‐loss: two‐ray model”
Blackboard Notes
Log‐Distance Path Loss Model
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 68
frey
Blackboard Notes
Log‐Distance Path Loss Model
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 69
frey
Blackboard Notes
Log‐Distance Path Loss Model
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 70
frey
Blackboard Notes
Log‐Distance Path Loss Model
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 71
rappaport02wireless: 4.9.1
Model parameters discussed
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 72
rappaport02wireless: 4.9.1
Reference distance d
0• has to be in the far field
• should be less than “typical distances” of the considered system
• commonly used values
• 1km for large coverage cellular system
• much smaller (such as 100m or 1m) for microcellular systems Distance d between transmitter and receiver
Path loss PL(d
0)at reference distance d
0• computed either from free space propagation model or
• determined empirically
Path loss exponent n (often also noted as α).
Typical path loss exponents obtained in various mobile radio environments
Image source: Theodore S. Rappaport, Wireless Communications, 2nd ed., Prentice Hall, 2002, page 139
Blackboard Notes
Log‐Normal Shadowing
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 73
rappaport02wireless: 4.9.2
Blackboard Notes
Log‐Normal Shadowing
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 74
rappaport02wireless: 4.9.2
Empirical Evidence (Example)
WS 18/19 Drahtlose Kommunikation - Technische Grundlagen 75
saunders07wireless: 9.2
Driving around a base station at a constant distance.
Depicted is the local mean after subtracting the median (50%) level in decibles.
The typical shape of the probability density function of shadowing compared to the PDF of the log-normal distribution.
Image source: Saunders, S., & Aragón-Zavala, A. (2007). Antennas and Propagation for Wireless Communication Systems (2nd Edition). Wiley (Fig. 9.2 and Fig. 9.3)
