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A Survey of Intercarrier Interference
Cancellation Schemes in MIMO-OFDM System
-- Alka Kalra and Rajesh Khanna
Orthogonal Frequency-Division Multiplexing
(OFDM) can be used in conjunction with a Multiple Input Multiple
Output (MIMO) transceiver to increase the diversity gain and/or the system capacity by exploiting spatial domain. The
combination of MIMO techniques with OFDM (MIMO-OFDM) is regarded as a promising solution to enhance the data rate of
future broadband wireless communication systems. The great finding was that the well-known
flat fading MIMO algorithms can be reused on a carrier-by-carrier basis since the channel becomes orthogonal in the frequency domain with
OFDM. This reduces the computational effort and makes MIMO-OFDM attractive for mobile applications. The performance
of wireless systems is however limited by multipath fading and interference from other users. In MIMO-OFDM
systems, instability of transmitter/receiver Radio Frequency
(RF) oscillators and the time varying fading channels can destroy
the orthogonality of subcarriers. This causes serious
Intercarrier Interference (ICI), thus leading to significant system
performance degradation which becomes more severe as the normalized
doppler frequency increases. ICI is a major
performance limiter in MIMO-OFDM systems. The ICI cancellation in
MIMO-OFDM system is an active area of research. In this
paper, a review of ICI cancellation techniques has been presented.
© 2011 IUP. All Rights Reserved.
Design and Analysis of a
Modified-Cyclic-Banyan-Based Atm/Ip
Switching Fabric Using Jenq's Model
-- V S Tripathi and S Tiwari
This paper focuses on the analysis of a large N
´ N high-performance Fast Packet switch suitable for mixed ATM and
IP traffic. It is a Banyan network using cyclic interconnection among switching elements of the same stage. We
employ deflection-routing algorithm in each switching element. The proposed routing is as simple as that of the generic
banyan network, and all the Switching Elements (SEs) have a uniform structure. To design the proposed network and to
develop its self-routing property, we observe that all the SEs of the
banyan network are arranged in a regular pattern
topologically. We, thus, present a growable switch architecture based on the topological properties of
banyan networks. As a result, we show that the new network has a far better performance than the other networks.
© 2011 IUP. All Rights Reserved.
A TDMA-Based MAC-Protocol
for Ad Hoc Networks
-- Jorma Jormakka
The paper proposes a Medium Access Control
(MAC)-protocol for medium-size-Ad Hoc networks. The protocol
supports quality-of-service over several hops by reservation of time slots. As a new feature, the protocol avoids the hidden
and exposed terminal problem by a two-hop reservation, not by the RTS/CTS protocol.
© 2011 IUP. All Rights Reserved.
A Simple Slot-Fed Cylindrical
Dielectric Resonator Antenna
-- R G Madhuri, P M Hadalgi and S L Mallikarjun
This paper experimentally studies a simple slot-fed
Cylindrical Dielectric Resonator Antenna (CDRA). The antenna
consists of a Cylindrical Dielectric Resonator
(CDR) fed by a microstrip line feed through a coupling slot. The study is carried
out by using three antennas with different Dielectric
Resonator (DR) thickness and provides dual bands with
improved bandwidth. It is observed that the impedance bandwidth increases from 37.09% to 70.9% as the thickness of DR
is increased. The return loss and radiation patterns of the proposed antennas are measured and presented.
© 2011 IUP. All Rights Reserved.
Optimization of Five-Element
Nu-Dipole Yagi-Uda Antenna Using Genetic Algorithms
-- Dauda Umar Suleiman
The paper analyzes the radiation characteristics of an optimized five-element Nu-dipole
Yagi-Uda antenna array. Integro-differential equation for the antenna array was formulated. Method of Moment
(MOM) technique was then used to convert the formulated integro-differential equation into a matrix form in order to
obtain current distribution on the array. Upon computing the current distribution on the antenna array, maximum directive
gain, input impedance(Zin) and far zone electric field
(Eq(q, f = 90°)) were obtained for uniformly perturbed directors'
element lengths and spacings. A combination of MOM and Genetic Algorithm (GA) was used to maximize directive gain as
a single objective function for the five-element
array. Directive gain and input impedance of 12.31
(dB) and Zin = 4.46 + j 27.0
(W) and 11.71 (dB) and Zin = 2.41 - j 2.70 (W) were obtained for Micro-GA and Conventional-GA, respectively.
These results were better when compared to 11.00
(dB) and Zin = 2.94 + j 7.20 (W) for the uniform perturbation. Composite objective function
comprising directive gain and input impedance produced values of 9.58
(dB) and Zin = 75.80 - j 0.60 (W) for Micro-GA and 9.60 (dB) and Zin = 75.48 + j 5.35 (W) for Conventional-GA, respectively.
© 2011 IUP. All Rights Reserved.
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