OFDM IN MOBILE COMMUNICATION

1. SUBJECT : (EC 598) OVERVIEW OF MOBILE COMMUNICATION
GAURAV BISWAS
BIT MESRA
THE OFDM BASED SYSTEMS
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2. Sr.
No.
TOPICS Slide No.
1. OFDM 4 - 7
2. OFDM APPLICATIONS 8
3. COMPONENTS OF OFDM 9
4. SYNCHRONIZATION IN OFDM 10
5. THE OFDM BASED SYSTEMS 11 - 13
6. USAGE IN ADSL 14 - 16
7. USAGE IN POWERLINE TECHNOLOGY 17 - 20
8. REFRENCES 21
INDEX
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3. • OFDM stands for (Orthogonal
frequency-division multiplexing)
• (OFDM) is a method of encoding digital
data on multiple carrier frequencies
• OFDM has developed into a popular
scheme for wideband digital
communication
OFDM
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4. OFDM
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Fig. no. 1 : OFDM Signal

5. • It is a frequency-division
multiplexing (FDM) scheme used as a
digital multi-carrier modulation method
OFDM
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6. • Block diagram of Digital muti-carrier modulation
OFDM
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Fig. no. 2 : Digital multi- carrier modulation

7. • It is used in applications such as
 Digital television
 Audio broadcasting
 DSL internet access
 Wireless networks
 Power line networks
 4G mobile communication
OFDMAPPLICATIONS
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8. • Modulator
• Serial to Parallel
Converter
• Parallel to Serial
Converter
• IFFT
• Digital to Analog
Converter
• Low Pass Filter
• Analog to digital
Converter
• FFT
• Demodulator
COMPONENTS OF OFDM
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9. • Done by three methods :
Data Aided (pilot assisted) method
Non – Data Aided (blind) method
Hybrid method
SYNCHRONIZATIONIN OFDM
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10. • Wireless Networks
 The WLAN radio interfaces IEEE
802.11a and HIPERLAN/2
 The terrestrial mobile TV systems DVB-
H, T-DMB, ISDB-T and Media FLO
forward link
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11. The wireless personal area network
Ultra-Wideband (UWB) IEEE
802.15.3a implementation suggested
by Wi-Media Alliance
The digital radio systems
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12. • Wired Version
 Mostly known as Discrete Multi-tone
Transmission (DMT)
 ADSL and VDSL broadband access
via POTS copper wiring
 Multimedia over Coax Alliance (MoCA)
home networking
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13. • Usage in ADSL
 It is used in ADSL connections that
follow the ANSI
T1.413 and G.dmt (ITU G.992.1)
standard
 DSL achieves high-speed data
connections on existing copper wires
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14.  Long copper wires suffer from
attenuation at high frequencies
 OFDM can cope with this frequency
selective attenuation and with narrow-
band interference
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15. • ADSL (Asymmetric digital subscriber line)
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Fig. no. 3 : ADSL

16. • Usage in Powerline Technology
It is used by many powerline devices to
extend digital connections through
power wiring
 Adaptive modulation is particularly
important with such a noisy channel as
electrical wiring
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17. IEEE 1901 standards include two
incompatible physical layers that both
use OFDM
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18. • Powerline technology
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Fig. no. 4 : Powerline Technology

19.  ITU-T G.hn standard, which provides high-
speed local area networking over existing
home wiring
Based on a PHY layer that specifies OFDM
with adaptive modulation and a Low-Density
Parity-Check & FEC code
THE OFDMBASEDSYSTEMS
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20. [1] Internet , Wikipedia (OFDM)
[2] Internet , Google Images
[3] Wireless Communication , Dr. Sanjay
Kumar , Edition 2015.
REFERENCES
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