26-04-2010, 10:21 AM
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Wireless Technologies :IEEE 802.11g OFDM system Convergence to 4G
Abstract:
This paper gives a brief description on Cellular Wireless Systems & Wireless Networks, and 802.11g OFDM PHY developments. System Description Development Framework Future Areas - Convergence to 4G.
Presented By:
Ms. Sasmita Rani Tripathy, Mr. Bidyut Majumdar
IACR, Rayagada
Introduction
Wireless is the next giant leap in information services. The new paradigm for connectivity enables business to operate
faster
better
more cost effectively
and more profitably
Through the use of
always on,
always connected, and
always available content and applications.
With the tremendous increase in wireless LANs, Mobile phones, PDAs, and other mobile devices, the merging of computation and telecommunication technologies is a fundamental part of modern society. Can broadly be classified into two types “ Cellular Wireless Systems and Wireless Networks
Cellular Wireless Systems Roadmap
OFDM Overview
Multi-Carrier Modulation Technique
Carrier spacing kept minimum maintaining orthogonality
Multi-path robustness due to multi-carrier
Reduction of ISI through Guard Bands
Robust against narrow-band interference
Efficient FFT based receiver structures
Simpler Frequency Domain Channel Equalization
Simpler Receiver Synchronization Techniques
High peak-to-average power levels
Susceptible to RF Front-end non-linearity
Susceptible to LO frequency offset / drift
Areas of future “ Convergence to 4G
4G is whatever that is beyond 3G
To be used for Real-Time Video Delivery and similar applications
QOS is important
Calls for more efficient Modulation, ECC and Equalization
Incorporation of Mobility and stringent Multipath including non- LOS
scenario into Wireless Networks can lead to 4G
OFDM and UWB likely candidates for 4G PHY
Space-Time Diversity, Smart Antenna Processing and Multiple-Input-
Multiple-Output (MIMO) systems are also likely to be used
CDMA with its multi-user capabilities can provide the access mechanism
Calls for implementation of a MAC layer that seamlessly integrates all the
above features of PHY
Acknowledgement:
Authors are thankful to Authorities of IACR, Rayagada for providing a scope for presentation of paper and Prof. S.P. Panigrahi for sharing his knowledge and guidance