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2014-10-27, 07:49 AM
Radio Propagation Basics
ITU Academy
November 2013
CONTENTS
I. Introduction
SNR objectives
Definitions: dB, dBm, dBi
FREQUENCY AND SYSTEM BANDS
SPECTRUM ALLOCATION IN EUROPE
II. Basic mechanisms of propagation in the radio mobile environment
BASICS PROPAGATION MECHANISMS
PROPAGATION PHENOMENA
PROPERTIES OF RADIO MOBILE CHANNEL
SIGNAL ATTENUATION IN DIFFERENT ENVIRONMENTS
DEGRADATION UNDERGONE BY THE WAVE
ATTENUATION IN RELATION TO THE FREQUENCY
PROPAGATION IN FREE SPACE
SIMPLIFIED MODEL PATHLOSS
PATHLOSS EXPONENT VALUES
EXAMPLE: LOSSES IN FREE PACE
ATTENUATION IN COMMUNICATION PER SATELLITE
RELATION BETWEEN DB AND S/N RATIO
SHADOWING EFFECTS
PROPAGATION WITHOUT DIRECT VISION
VEGETATION IMPACT
DIFFUSION PHENOMENA
EXERCISE : APPLICATION OF WEISSBERGER FORMULA
LOSSES DUE TO BUILDING
LOSSES DUE TO WEATHER
DIFFRACTION FRESNEL ZONES (1)
DIFFRACTION FRESNEL ZONES (2)
DIFFRACTION FRESNEL ZONES (3)
DIFFRACTION FRESNEL ZONES (4)
FIRST FRESNEL ZONE
MULTIPATH
MULTIPATH : POSITIVE EFFECT
MULTIPATH : NEGATIVE EFFECT
MULTIPATH ENVIRONMENT
EXAMPLE : CALCULATION OF DELAY SPREAD
DELAY SPREAD AND COHERENCE BANDWIDTH
FREQUENCY SELECTIVITY
PROBLEM : INTERSYMBOL INTERFERENCE (1)
PROBLEM : INTERSYMBOL INTERFERENCE (2)
INTERSYMBOL INTERFERENCE (ISI)
EXAMPLE
DELAY SPREAD VALUES
EQUALIZATION AND DELAY SPREAD IN GSM
RAYLEIGH FADING (1)
RAYLEIGH FADING (2)
RAYLEIGH 2D ENVIRONMENT
FAST FADING : NARROW BAND
FADING CHARACTERISTICS
RAYLEIGH 3D ENVIRONMENT
EXAMPLE : DURATION BETWEEN FADING HOLES
AVERAGE DURATION OF A FADING HOLE
DOPPLER SHIFT (1)
DOPPLER SHIFT (2)
IMPACTS OF THE PROPAGATION INTO QPSK MODULATION
FADING TYPES
III. Interference and noise
COMMUNICATION SYSTEM EFFICIENCY AND NOISE
INTERFERENCE
INTERFERENCE IN ADJACENT CHANNELS
INTERFERENCE CO-CHANNELS
NOISE
NOISE IN THE RADIO MOBILE CHANNEL
IV. Radio Propagation Models
Simplified pathloss model
Pathloss exponent values
Free Air Space Model
Flat Landform Propagation Model
Propagation prediction models
Large scale propagation models typology
Okumura-Hata model (1)
Okumura-Hata model (2)
Okumura-Hata model (3)
Okumura-Hata model (4)
Okumura-Hata model (5)
Walfish-Ikegami/COST231 model (1)
Walfish-Ikegami/COST231 model (2)
Walfish-Ikegami/COST231 model (3)
Motley empirical model
Radio Propagation Models
Ray tracing
Knife-edge diffraction models
Deygout model (1)
Deygout model (2)
V. Propagation models calibration
General problematic
Global process
Measurements campaign
Site selection
Test Platform
Test Path
Drive test
Results example
Calibration curves
Geographical databases
Digital Terrain Models
Digital terrain map
DTM + Clutter
3D DB
Geographical eographical databases
Traffic density map
ITU Academy
November 2013
CONTENTS
I. Introduction
SNR objectives
Definitions: dB, dBm, dBi
FREQUENCY AND SYSTEM BANDS
SPECTRUM ALLOCATION IN EUROPE
II. Basic mechanisms of propagation in the radio mobile environment
BASICS PROPAGATION MECHANISMS
PROPAGATION PHENOMENA
PROPERTIES OF RADIO MOBILE CHANNEL
SIGNAL ATTENUATION IN DIFFERENT ENVIRONMENTS
DEGRADATION UNDERGONE BY THE WAVE
ATTENUATION IN RELATION TO THE FREQUENCY
PROPAGATION IN FREE SPACE
SIMPLIFIED MODEL PATHLOSS
PATHLOSS EXPONENT VALUES
EXAMPLE: LOSSES IN FREE PACE
ATTENUATION IN COMMUNICATION PER SATELLITE
RELATION BETWEEN DB AND S/N RATIO
SHADOWING EFFECTS
PROPAGATION WITHOUT DIRECT VISION
VEGETATION IMPACT
DIFFUSION PHENOMENA
EXERCISE : APPLICATION OF WEISSBERGER FORMULA
LOSSES DUE TO BUILDING
LOSSES DUE TO WEATHER
DIFFRACTION FRESNEL ZONES (1)
DIFFRACTION FRESNEL ZONES (2)
DIFFRACTION FRESNEL ZONES (3)
DIFFRACTION FRESNEL ZONES (4)
FIRST FRESNEL ZONE
MULTIPATH
MULTIPATH : POSITIVE EFFECT
MULTIPATH : NEGATIVE EFFECT
MULTIPATH ENVIRONMENT
EXAMPLE : CALCULATION OF DELAY SPREAD
DELAY SPREAD AND COHERENCE BANDWIDTH
FREQUENCY SELECTIVITY
PROBLEM : INTERSYMBOL INTERFERENCE (1)
PROBLEM : INTERSYMBOL INTERFERENCE (2)
INTERSYMBOL INTERFERENCE (ISI)
EXAMPLE
DELAY SPREAD VALUES
EQUALIZATION AND DELAY SPREAD IN GSM
RAYLEIGH FADING (1)
RAYLEIGH FADING (2)
RAYLEIGH 2D ENVIRONMENT
FAST FADING : NARROW BAND
FADING CHARACTERISTICS
RAYLEIGH 3D ENVIRONMENT
EXAMPLE : DURATION BETWEEN FADING HOLES
AVERAGE DURATION OF A FADING HOLE
DOPPLER SHIFT (1)
DOPPLER SHIFT (2)
IMPACTS OF THE PROPAGATION INTO QPSK MODULATION
FADING TYPES
III. Interference and noise
COMMUNICATION SYSTEM EFFICIENCY AND NOISE
INTERFERENCE
INTERFERENCE IN ADJACENT CHANNELS
INTERFERENCE CO-CHANNELS
NOISE
NOISE IN THE RADIO MOBILE CHANNEL
IV. Radio Propagation Models
Simplified pathloss model
Pathloss exponent values
Free Air Space Model
Flat Landform Propagation Model
Propagation prediction models
Large scale propagation models typology
Okumura-Hata model (1)
Okumura-Hata model (2)
Okumura-Hata model (3)
Okumura-Hata model (4)
Okumura-Hata model (5)
Walfish-Ikegami/COST231 model (1)
Walfish-Ikegami/COST231 model (2)
Walfish-Ikegami/COST231 model (3)
Motley empirical model
Radio Propagation Models
Ray tracing
Knife-edge diffraction models
Deygout model (1)
Deygout model (2)
V. Propagation models calibration
General problematic
Global process
Measurements campaign
Site selection
Test Platform
Test Path
Drive test
Results example
Calibration curves
Geographical databases
Digital Terrain Models
Digital terrain map
DTM + Clutter
3D DB
Geographical eographical databases
Traffic density map