Submit Search
Upload
Chapt-03.ppt
•
Download as PPT, PDF
•
0 likes
•
3 views
F
FadilWijYa
Follow
propagation .sistem transmisi dan telekomunikasi
Read less
Read more
Engineering
Slideshow view
Report
Share
Slideshow view
Report
Share
1 of 35
Download now
Recommended
Mobile Radio Propagation
Mobile Radio Propagation
Izah Asmadi
Chapt 03
Chapt 03
Anuj Sharma
chapt-03-140628235756-phpapp01.pdf
chapt-03-140628235756-phpapp01.pdf
MRehman9
Mobile Radio Propagations
Mobile Radio Propagations
METHODIST COLLEGE OF ENGG & TECH
microwave_communications1__1.pptx
microwave_communications1__1.pptx
GeoffreyAlleyne
Introduction & Wireless Transmission
Introduction & Wireless Transmission
Joe Christensen
The Wireless Channel Propagation
The Wireless Channel Propagation
Pei-Che Chang
Wc nots final unit new 7
Wc nots final unit new 7
SURESHA V
Recommended
Mobile Radio Propagation
Mobile Radio Propagation
Izah Asmadi
Chapt 03
Chapt 03
Anuj Sharma
chapt-03-140628235756-phpapp01.pdf
chapt-03-140628235756-phpapp01.pdf
MRehman9
Mobile Radio Propagations
Mobile Radio Propagations
METHODIST COLLEGE OF ENGG & TECH
microwave_communications1__1.pptx
microwave_communications1__1.pptx
GeoffreyAlleyne
Introduction & Wireless Transmission
Introduction & Wireless Transmission
Joe Christensen
The Wireless Channel Propagation
The Wireless Channel Propagation
Pei-Che Chang
Wc nots final unit new 7
Wc nots final unit new 7
SURESHA V
C cf radio propagation theory and propagation models
C cf radio propagation theory and propagation models
Tempus Telcosys
ashkkadjhasjdhkae2312433521433.pdf
ashkkadjhasjdhkae2312433521433.pdf
VidyaDufare
Chapter#5
Chapter#5
Syed Muhammad ALi Shah
LOW,MEDIUM,HIGH_Doppler_MTI.pptx
LOW,MEDIUM,HIGH_Doppler_MTI.pptx
FirstknightPhyo
Introduction to Wireless Communication
Introduction to Wireless Communication
Dilum Bandara
Lecture on mobile radio environme, nt.ppt
Lecture on mobile radio environme, nt.ppt
NanaAgyeman13
lectureradio.pdfSDFDÀDFSDSFSDFDFSFDFSFED
lectureradio.pdfSDFDÀDFSDSFSDFDFSFDFSFED
tHunh5775
LOW,MEDIUM,HIGH_Doppler_MTI.pdf
LOW,MEDIUM,HIGH_Doppler_MTI.pdf
FirstknightPhyo
mobile radio propagation and fading
mobile radio propagation and fading
GRAKESHKUMAR
Channel Models for Massive MIMO
Channel Models for Massive MIMO
CPqD
Wireless Communication Unit 3.pptx
Wireless Communication Unit 3.pptx
Karan Belsare
wireless communications
wireless communications
faisalsaad18
Antennas propagation
Antennas propagation
hrishi_tiwary
N 4-antennas propagation
N 4-antennas propagation
15010192
Amplitude Modulation using Multipliers and Envelope Detector
Amplitude Modulation using Multipliers and Envelope Detector
j naga sai
Introduction To Wireless Fading Channels
Introduction To Wireless Fading Channels
Nitin Jain
Chap 4 (large scale propagation)
Chap 4 (large scale propagation)
asadkhan1327
Third Generation Wireless Modeling in Urban Environment
Third Generation Wireless Modeling in Urban Environment
EECJOURNAL
713_Transmission_Lines-F21.ppt
713_Transmission_Lines-F21.ppt
yash919530
713_Transmission_Lines-F21.ppt
713_Transmission_Lines-F21.ppt
HalarMustafa1
VIP Call Girls Service Hitech City Hyderabad Call +91-8250192130
VIP Call Girls Service Hitech City Hyderabad Call +91-8250192130
Suhani Kapoor
247267395-1-Symmetric-and-distributed-shared-memory-architectures-ppt (1).ppt
247267395-1-Symmetric-and-distributed-shared-memory-architectures-ppt (1).ppt
ssuser5c9d4b1
More Related Content
Similar to Chapt-03.ppt
C cf radio propagation theory and propagation models
C cf radio propagation theory and propagation models
Tempus Telcosys
ashkkadjhasjdhkae2312433521433.pdf
ashkkadjhasjdhkae2312433521433.pdf
VidyaDufare
Chapter#5
Chapter#5
Syed Muhammad ALi Shah
LOW,MEDIUM,HIGH_Doppler_MTI.pptx
LOW,MEDIUM,HIGH_Doppler_MTI.pptx
FirstknightPhyo
Introduction to Wireless Communication
Introduction to Wireless Communication
Dilum Bandara
Lecture on mobile radio environme, nt.ppt
Lecture on mobile radio environme, nt.ppt
NanaAgyeman13
lectureradio.pdfSDFDÀDFSDSFSDFDFSFDFSFED
lectureradio.pdfSDFDÀDFSDSFSDFDFSFDFSFED
tHunh5775
LOW,MEDIUM,HIGH_Doppler_MTI.pdf
LOW,MEDIUM,HIGH_Doppler_MTI.pdf
FirstknightPhyo
mobile radio propagation and fading
mobile radio propagation and fading
GRAKESHKUMAR
Channel Models for Massive MIMO
Channel Models for Massive MIMO
CPqD
Wireless Communication Unit 3.pptx
Wireless Communication Unit 3.pptx
Karan Belsare
wireless communications
wireless communications
faisalsaad18
Antennas propagation
Antennas propagation
hrishi_tiwary
N 4-antennas propagation
N 4-antennas propagation
15010192
Amplitude Modulation using Multipliers and Envelope Detector
Amplitude Modulation using Multipliers and Envelope Detector
j naga sai
Introduction To Wireless Fading Channels
Introduction To Wireless Fading Channels
Nitin Jain
Chap 4 (large scale propagation)
Chap 4 (large scale propagation)
asadkhan1327
Third Generation Wireless Modeling in Urban Environment
Third Generation Wireless Modeling in Urban Environment
EECJOURNAL
713_Transmission_Lines-F21.ppt
713_Transmission_Lines-F21.ppt
yash919530
713_Transmission_Lines-F21.ppt
713_Transmission_Lines-F21.ppt
HalarMustafa1
Similar to Chapt-03.ppt
(20)
C cf radio propagation theory and propagation models
C cf radio propagation theory and propagation models
ashkkadjhasjdhkae2312433521433.pdf
ashkkadjhasjdhkae2312433521433.pdf
Chapter#5
Chapter#5
LOW,MEDIUM,HIGH_Doppler_MTI.pptx
LOW,MEDIUM,HIGH_Doppler_MTI.pptx
Introduction to Wireless Communication
Introduction to Wireless Communication
Lecture on mobile radio environme, nt.ppt
Lecture on mobile radio environme, nt.ppt
lectureradio.pdfSDFDÀDFSDSFSDFDFSFDFSFED
lectureradio.pdfSDFDÀDFSDSFSDFDFSFDFSFED
LOW,MEDIUM,HIGH_Doppler_MTI.pdf
LOW,MEDIUM,HIGH_Doppler_MTI.pdf
mobile radio propagation and fading
mobile radio propagation and fading
Channel Models for Massive MIMO
Channel Models for Massive MIMO
Wireless Communication Unit 3.pptx
Wireless Communication Unit 3.pptx
wireless communications
wireless communications
Antennas propagation
Antennas propagation
N 4-antennas propagation
N 4-antennas propagation
Amplitude Modulation using Multipliers and Envelope Detector
Amplitude Modulation using Multipliers and Envelope Detector
Introduction To Wireless Fading Channels
Introduction To Wireless Fading Channels
Chap 4 (large scale propagation)
Chap 4 (large scale propagation)
Third Generation Wireless Modeling in Urban Environment
Third Generation Wireless Modeling in Urban Environment
713_Transmission_Lines-F21.ppt
713_Transmission_Lines-F21.ppt
713_Transmission_Lines-F21.ppt
713_Transmission_Lines-F21.ppt
Recently uploaded
VIP Call Girls Service Hitech City Hyderabad Call +91-8250192130
VIP Call Girls Service Hitech City Hyderabad Call +91-8250192130
Suhani Kapoor
247267395-1-Symmetric-and-distributed-shared-memory-architectures-ppt (1).ppt
247267395-1-Symmetric-and-distributed-shared-memory-architectures-ppt (1).ppt
ssuser5c9d4b1
HARMONY IN THE NATURE AND EXISTENCE - Unit-IV
HARMONY IN THE NATURE AND EXISTENCE - Unit-IV
RajaP95
Structural Analysis and Design of Foundations: A Comprehensive Handbook for S...
Structural Analysis and Design of Foundations: A Comprehensive Handbook for S...
Dr.Costas Sachpazis
(RIA) Call Girls Bhosari ( 7001035870 ) HI-Fi Pune Escorts Service
(RIA) Call Girls Bhosari ( 7001035870 ) HI-Fi Pune Escorts Service
ranjana rawat
Analog to Digital and Digital to Analog Converter
Analog to Digital and Digital to Analog Converter
AbhinavSharma374939
Introduction to Multiple Access Protocol.pptx
Introduction to Multiple Access Protocol.pptx
upamatechverse
Software Development Life Cycle By Team Orange (Dept. of Pharmacy)
Software Development Life Cycle By Team Orange (Dept. of Pharmacy)
Suman Mia
9953056974 Call Girls In South Ex, Escorts (Delhi) NCR.pdf
9953056974 Call Girls In South Ex, Escorts (Delhi) NCR.pdf
9953056974 Low Rate Call Girls In Saket, Delhi NCR
High Profile Call Girls Nagpur Meera Call 7001035870 Meet With Nagpur Escorts
High Profile Call Girls Nagpur Meera Call 7001035870 Meet With Nagpur Escorts
Call Girls in Nagpur High Profile
OSVC_Meta-Data based Simulation Automation to overcome Verification Challenge...
OSVC_Meta-Data based Simulation Automation to overcome Verification Challenge...
Soham Mondal
Porous Ceramics seminar and technical writing
Porous Ceramics seminar and technical writing
rakeshbaidya232001
ZXCTN 5804 / ZTE PTN / ZTE POTN / ZTE 5804 PTN / ZTE POTN 5804 ( 100/200 GE Z...
ZXCTN 5804 / ZTE PTN / ZTE POTN / ZTE 5804 PTN / ZTE POTN 5804 ( 100/200 GE Z...
ZTE
Microscopic Analysis of Ceramic Materials.pptx
Microscopic Analysis of Ceramic Materials.pptx
purnimasatapathy1234
IVE Industry Focused Event - Defence Sector 2024
IVE Industry Focused Event - Defence Sector 2024
Mark Billinghurst
Sheet Pile Wall Design and Construction: A Practical Guide for Civil Engineer...
Sheet Pile Wall Design and Construction: A Practical Guide for Civil Engineer...
Dr.Costas Sachpazis
Processing & Properties of Floor and Wall Tiles.pptx
Processing & Properties of Floor and Wall Tiles.pptx
pranjaldaimarysona
High Profile Call Girls Nashik Megha 7001305949 Independent Escort Service Na...
High Profile Call Girls Nashik Megha 7001305949 Independent Escort Service Na...
Call Girls in Nagpur High Profile
(ANJALI) Dange Chowk Call Girls Just Call 7001035870 [ Cash on Delivery ] Pun...
(ANJALI) Dange Chowk Call Girls Just Call 7001035870 [ Cash on Delivery ] Pun...
ranjana rawat
VIP Call Girls Service Kondapur Hyderabad Call +91-8250192130
VIP Call Girls Service Kondapur Hyderabad Call +91-8250192130
Suhani Kapoor
Recently uploaded
(20)
VIP Call Girls Service Hitech City Hyderabad Call +91-8250192130
VIP Call Girls Service Hitech City Hyderabad Call +91-8250192130
247267395-1-Symmetric-and-distributed-shared-memory-architectures-ppt (1).ppt
247267395-1-Symmetric-and-distributed-shared-memory-architectures-ppt (1).ppt
HARMONY IN THE NATURE AND EXISTENCE - Unit-IV
HARMONY IN THE NATURE AND EXISTENCE - Unit-IV
Structural Analysis and Design of Foundations: A Comprehensive Handbook for S...
Structural Analysis and Design of Foundations: A Comprehensive Handbook for S...
(RIA) Call Girls Bhosari ( 7001035870 ) HI-Fi Pune Escorts Service
(RIA) Call Girls Bhosari ( 7001035870 ) HI-Fi Pune Escorts Service
Analog to Digital and Digital to Analog Converter
Analog to Digital and Digital to Analog Converter
Introduction to Multiple Access Protocol.pptx
Introduction to Multiple Access Protocol.pptx
Software Development Life Cycle By Team Orange (Dept. of Pharmacy)
Software Development Life Cycle By Team Orange (Dept. of Pharmacy)
9953056974 Call Girls In South Ex, Escorts (Delhi) NCR.pdf
9953056974 Call Girls In South Ex, Escorts (Delhi) NCR.pdf
High Profile Call Girls Nagpur Meera Call 7001035870 Meet With Nagpur Escorts
High Profile Call Girls Nagpur Meera Call 7001035870 Meet With Nagpur Escorts
OSVC_Meta-Data based Simulation Automation to overcome Verification Challenge...
OSVC_Meta-Data based Simulation Automation to overcome Verification Challenge...
Porous Ceramics seminar and technical writing
Porous Ceramics seminar and technical writing
ZXCTN 5804 / ZTE PTN / ZTE POTN / ZTE 5804 PTN / ZTE POTN 5804 ( 100/200 GE Z...
ZXCTN 5804 / ZTE PTN / ZTE POTN / ZTE 5804 PTN / ZTE POTN 5804 ( 100/200 GE Z...
Microscopic Analysis of Ceramic Materials.pptx
Microscopic Analysis of Ceramic Materials.pptx
IVE Industry Focused Event - Defence Sector 2024
IVE Industry Focused Event - Defence Sector 2024
Sheet Pile Wall Design and Construction: A Practical Guide for Civil Engineer...
Sheet Pile Wall Design and Construction: A Practical Guide for Civil Engineer...
Processing & Properties of Floor and Wall Tiles.pptx
Processing & Properties of Floor and Wall Tiles.pptx
High Profile Call Girls Nashik Megha 7001305949 Independent Escort Service Na...
High Profile Call Girls Nashik Megha 7001305949 Independent Escort Service Na...
(ANJALI) Dange Chowk Call Girls Just Call 7001035870 [ Cash on Delivery ] Pun...
(ANJALI) Dange Chowk Call Girls Just Call 7001035870 [ Cash on Delivery ] Pun...
VIP Call Girls Service Kondapur Hyderabad Call +91-8250192130
VIP Call Girls Service Kondapur Hyderabad Call +91-8250192130
Chapt-03.ppt
1.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 1 Chapter 3 Mobile Radio Propagation
2.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 2 Outline Speed, Wavelength, Frequency Types of Waves Radio Frequency Bands Propagation Mechanisms Radio Propagation Effects Free-Space Propagation Land Propagation Path Loss Fading: Slow Fading / Fast Fading Delay Spread Doppler Shift Co-Channel Interference The Near-Far Problem Digital Wireless Communication System Analog and Digital Signals Modulation Techniques
3.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 3 Speed, Wavelength, Frequency System Frequency Wavelength AC current 60 Hz 5,000 km FM radio 100 MHz 3 m Cellular 800 MHz 37.5 cm Ka band satellite 20 GHz 15 mm Ultraviolet light 1015 Hz 10-7 m Light speed = Wavelength x Frequency = 3 x 108 m/s = 300,000 km/s
4.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 4 Types of Waves Earth Sky wave Space wave Ground wave Troposphere (0 - 12 km) Stratosphere (12 - 50 km) Mesosphere (50 - 80 km) Ionosphere (80 - 720 km)
5.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 5 Radio Frequency Bands Classification Band Initials Frequency Range Characteristics Extremely low ELF < 300 Hz Ground wave Infra low ILF 300 Hz - 3 kHz Very low VLF 3 kHz - 30 kHz Low LF 30 kHz - 300 kHz Medium MF 300 kHz - 3 MHz Ground/Sky wave High HF 3 MHz - 30 MHz Sky wave Very high VHF 30 MHz - 300 MHz Space wave Ultra high UHF 300 MHz - 3 GHz Super high SHF 3 GHz - 30 GHz Extremely high EHF 30 GHz - 300 GHz Tremendously high THF 300 GHz - 3000 GHz
6.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 6 Propagation Mechanisms Reflection Propagation wave impinges on an object which is large as compared to wavelength - e.g., the surface of the Earth, buildings, walls, etc. Diffraction Radio path between transmitter and receiver obstructed by surface with sharp irregular edges Waves bend around the obstacle, even when LOS (line of sight) does not exist Scattering Objects smaller than the wavelength of the propagation wave - e.g. foliage, street signs, lamp posts
7.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 7 Radio Propagation Effects Transmitter d Receiver hb hm Diffracted Signal Reflected Signal Direct Signal Building
8.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 8 Free-space Propagation The received signal power at distance d: where Pt is transmitting power, Ae is effective area, and Gt is the transmitting antenna gain. Assuming that the radiated power is uniformly distributed over the surface of the sphere. Transmitter Distance d Receiver hb hm 2 r 4 P d P G A t t e
9.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 9 Antenna Gain For a circular reflector antenna Gain G = ( D / )2 = net efficiency (depends on the electric field distribution over the antenna aperture, losses, ohmic heating , typically 0.55) D = diameter thus, G = ( D f /c )2, c = f (c is speed of light) Example: Antenna with diameter = 2 m, frequency = 6 GHz, wavelength = 0.05 m G = 39.4 dB Frequency = 14 GHz, same diameter, wavelength = 0.021 m G = 46.9 dB * Higher the frequency, higher the gain for the same size antenna
10.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 10 Land Propagation The received signal power: where Gr is the receiver antenna gain, L is the propagation loss in the channel, i.e., L = LP LS LF L P G G P t r t r Fast fading Slow fading Path loss
11.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 11 Path Loss (Free-space) Definition of path loss LP : Path Loss in Free-space: where fc is the carrier frequency. This shows greater the fc , more is the loss. , r t P P P L ), ( log 20 ) ( log 20 45 . 32 ) ( 10 10 km d MHz f dB L c PF
12.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 12 Path Loss (Land Propagation) Simplest Formula: Lp = A d-α where A and α: propagation constants d : distance between transmitter and receiver α : value of 3 ~ 4 in typical urban area
13.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 13 Example of Path Loss (Free-space) Path Loss in Free-space 70 80 90 100 110 120 130 0 5 10 15 20 25 30 Distance d (km) Path Loss Lf (dB) fc=150MHz fc=200MHz fc=400MHz fc=800MHz fc=1000MHz fc=1500MHz
14.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 14 Path Loss (Urban, Suburban and Open areas) Urban area: where Suburban area: Open area: ) ( log ) ( log 55 . 6 9 . 44 ) ( ) ( log 82 . 13 ) ( log 16 . 26 55 . 69 ) ( 10 10 10 10 km d m h m h m h MHz f dB L b m b c PU city medium small for MHz f for m h MHz f for m h city e l for MHz f m h MHz f m h c m c m c m c m & , 400 , 97 . 4 ) ( 75 . 11 log 2 . 3 200 , 1 . 1 ) ( 54 . 1 log 29 . 8 arg , 8 . 0 ) ( log 56 . 1 ) ( 7 . 0 ) ( log 1 . 1 ) ( 2 10 2 10 10 10 4 . 5 28 ) ( log 2 ) ( ) ( 2 10 MHz f dB L dB L c PU PS 94 . 40 ) ( log 33 . 18 ) ( log 78 . 4 ) ( ) ( 10 2 10 MHz f MHz f dB L dB L c c PU PO
15.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 15 Path Loss Path loss in decreasing order: Urban area (large city) Urban area (medium and small city) Suburban area Open area
16.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 16 Example of Path Loss (Urban Area: Large City) Path Loss in Urban Area in Large City 100 110 120 130 140 150 160 170 180 0 10 20 30 Distance d (km) Path Loss Lpu (dB) fc=200MHz fc=400MHz fc=800MHz fc=1000MHz fc=1500MHz fc=150MHz
17.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 17 Example of Path Loss (Urban Area: Medium and Small Cities) Path Loss in Urban Area for Small & Medium Cities 100 110 120 130 140 150 160 170 180 0 10 20 30 Distance d (km) Path Loss Lpu (dB) fc=150MHz fc=200MHz fc=400MHz fc=800MHz fc=1000MHz fc=1500MHz
18.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 18 Example of Path Loss (Suburban Area) Path Loss in Suburban Area 90 100 110 120 130 140 150 160 170 0 5 10 15 20 25 30 Distance d (km) Path Loss Lps (dB) fc=150MHz fc=200MHz fc=400MHz fc=800MHz fc=1000MHz fc=1500MHz
19.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 19 Example of Path Loss (Open Area) Path Loss in Open Area 80 90 100 110 120 130 140 150 0 5 10 15 20 25 30 Distance d (km) Path Loss Lpo (dB) fc=150MHz fc=200MHz fc=400MHz fc=800MHz fc=1000MHz fc=1500MHz
20.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 20 Fading Signal Strength (dB) Distance Path Loss Slow Fading (Long-term fading) Fast Fading (Short-term fading)
21.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 21 Slow Fading The long-term variation in the mean level is known as slow fading (shadowing or log-normal fading). This fading caused by shadowing. Log-normal distribution: - The pdf of the received signal level is given in decibels by where M is the true received signal level m in decibels, i.e., 10log10m, M is the area average signal level, i.e., the mean of M, is the standard deviation in decibels , 2 1 2 2 2 M M e M p
22.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 22 Log-normal Distribution M M 2 p(M) The pdf of the received signal level
23.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 23 Fast Fading The signal from the transmitter may be reflected from objects such as hills, buildings, or vehicles. When MS far from BS, the envelope distribution of received signal is Rayleigh distribution. The pdf is where is the standard deviation. Middle value rm of envelope signal within sample range to be satisfied by We have rm = 1.777 0 , 2 2 2 2 r e r r p r . 5 . 0 ) ( m r r P
24.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 24 Rayleigh Distribution The pdf of the envelope variation r 2 4 6 8 10 P(r) 0 0.2 0.4 0.6 0.8 1.0 =1 =2 =3
25.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 25 Fast Fading (Continued) When MS far from BS, the envelope distribution of received signal is Rician distribution. The pdf is where is the standard deviation, I0(x) is the zero-order Bessel function of the first kind, is the amplitude of the direct signal 0 , 0 2 2 2 2 2 r r I e r r p r
26.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 26 Rician Distribution r Pdf p(r) r 8 6 4 2 0 0.6 0.5 0.4 0.3 0.2 0.1 0 = 2 = 1 = 0 (Rayleigh) = 1 = 3 The pdf of the envelope variation
27.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 27 Characteristics of Instantaneous Amplitude Level Crossing Rate: Average number of times per second that the signal envelope crosses the level in positive going direction. Fading Rate: Number of times signal envelope crosses middle value in positive going direction per unit time. Depth of Fading: Ratio of mean square value and minimum value of fading signal. Fading Duration: Time for which signal is below given threshold.
28.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 28 Doppler Shift Doppler Effect: When a wave source and a receiver are moving towards each other, the frequency of the received signal will not be the same as the source. When they are moving toward each other, the frequency of the received signal is higher than the source. When they are opposing each other, the frequency decreases. Thus, the frequency of the received signal is where fC is the frequency of source carrier, fD is the Doppler frequency. Doppler Shift in frequency: where v is the moving speed, is the wavelength of carrier. cos v fD D C R f f f MS Signal Moving speed v
29.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 29 Delay Spread When a signal propagates from a transmitter to a receiver, signal suffers one or more reflections. This forces signal to follow different paths. Each path has different path length, so the time of arrival for each path is different. This effect which spreads out the signal is called “Delay Spread”.
30.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 30 Moving Speed Effect Time V1 V2 V3 V4 Signal strength
31.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 31 Delay Spread Delay Signal Strength The signals from close by reflectors The signals from intermediate reflectors The signals from far away reflectors
32.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 32 Intersymbol Interference (ISI) Caused by time delayed multipath signals Has impact on burst error rate of channel Second multipath is delayed and is received during next symbol For low bit-error-rate (BER) R (digital transmission rate) limited by delay spread d. d R 2 1
33.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 33 Intersymbol Interference (ISI) Time Time Time Transmission signal Received signal (short delay) Received signal (long delay) 1 0 1 Propagation time Delayed signals
34.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 34 Coherence Bandwidth Coherence bandwidth Bc: Represents correlation between 2 fading signal envelopes at frequencies f1 and f2. Is a function of delay spread. Two frequencies that are larger than coherence bandwidth fade independently. Concept useful in diversity reception Multiple copies of same message are sent using different frequencies.
35.
Copyright © 2003,
Dr. Dharma P. Agrawal and Dr. Qing-An Zeng. All rights reserved. 35 Cochannel Interference Cells having the same frequency interfere with each other. rd is the desired signal ru is the interfering undesired signal is the protection ratio for which rd ru (so that the signals interfere the least) If P(rd ru ) is the probability that rd ru , Cochannel probability Pco = P(rd ru )
Download now