10. types of small scale fading

10. types of small scale fading

1. WIRELESS COMMUNICATION
SERIES
Types of Small Scale Fading

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3. Based on
Time Delay
Spread
Based on
Doppler
Spread
Leads to
TIME
Dispersion
Leads to
FREQUENCY
Dispersion
FLAT FADING
FREQUENCY
SELECTIVE
FADING
FAST FADING
SLOW FADING
BW of signal < BW of Channel
Delay Spread < Symbol Period
BW of signal > BW of Channel
Delay Spread > Symbol Period
High Doppler Spread
Coherence Time < Symbol Period
BW of Channel Varies FASTER than BW of signal
Low Doppler Spread
Coherence Time > Symbol Period
BW of Channel Varies SLOWER than the BW of Signal
B
s<< B
c
??????
??????≪T
s
B
s>> B
c
??????
??????≫T
s
T
c<< T
s
B
s<< B
D
T
c>> T
s
B
s>> B
D

4. Based on
Time Delay
Spread
Based on
Doppler
Spread
FLAT FADING
FREQUENCY
SELECCTIVE
FADING
FAST FADING
SLOW FADING
B
s<< B
c
??????
??????≪T
s
B
s>> B
c
??????
??????≫T
s
T
c<< T
s
B
s<< B
D
T
c>> T
s
B
s>> B
D
T
s
T
s
B
s
B
s
??????
??????
T
c
B
c
B
D
FLAT FLAT
SLOW FAST
SLOW FAST
FREQ. SEL FREQ. SEL
FAST
FREQ. SEL
SLOW
FREQ. SEL
FLAT
FAST
FLAT
SLOW
MATRIX REPRESENTATION OF FADING
AS A FUNCTION OF SYMBOL PERIOD
MATRIX REPRESENTATION OF FADING
AS A FUNCTION OF SIGNAL BW

5. FADING
SMALL SCALE
FADING
MULTIPATH
DELAY
SPREAD
FLAT FADING
FREQUENCY
SELECTIVE
FADING
DOPPLER
SPREAD
FAST FADING SLOW FADING
LARGE SCALE
FADING
PATH LOSS SHADOWING

6. Summary of Module –1
Wireless Channels
•Largescalepathloss
•Pathlossmodels:
•FreeSpace
•Two-Raymodels
•LinkBudgetdesign
•LogDistancePathLossModel
•LogNormalShadowingModel
•Smallscalefading
•Parametersofmobilemultipath
channels
•Timedispersionparameters
•Coherencebandwidth
•Dopplerspread&Coherence
time,
•fadingduetoMultipathtimedelay
spread
•flatfading
•frequencyselectivefading
•FadingduetoDopplerspread
•fastfading
•slowfading.