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Analysis of Flipped Secant Inverse Hyperbolic
Pulse-Based FIR Filter for WCDMA
-- A S Kang and Vishal Sharma
Due to the increasing demand for video signal processing and transmission of high speed and higher
order, FIR filters have frequently been applied for performing adaptive pulse shaping and signal equalization
on received data in real time. Pulse shaping for wireless communication over time as well as frequency
selective channels is the need of the hour for 3G and 4G systems. Due to intensive use of digital filters in video
and communication systems, high performance in speed, area and power consumption is demanded. The
rapidly increasing popularity of mobile radio services has created a series of technological challenges. One of this
is the need for power and spectrally efficient modulation schemes to meet the spectral requirements of
mobile communications. Linear modulation methods such as QAM, QPSK, and OQPSK have received much
attention due to their inherent high spectral efficiency. However, for the efficient amplification of the transmitted
signal, the Radio Frequency Amplifier is normally operated near the saturation region and, therefore, exhibits
nonlinear behavior. As a result, significant spectral spreading occurs when a signal with large envelope
variations propagates through such an amplifier and creates large envelope fluctuations. Pulse shaping plays a
crucial role in spectral shaping in the modern wireless communication to reduce the spectral bandwidth. The
present paper deals with an analysis of flipped secant inverse hyperbolic pulse-based FIR filter for WCDMA.
© 2011 IUP. All Rights Reserved.
An Energy-Efficient Full Adder Design Based
on Energy Recovery Gates and Multiplexer Architecture
-- Manoj Kumar, Sandeep K Arya and Sujata Pandey
An energy-efficient single bit full adder based on energy recovery CMOS XOR/XNOR using Clocked
Adiabatic Logic (CAL), 2N-2N2P and transmission gate multiplexer has been presented in 0.35 µm technology.
The adder using CAL (20T) XNOR/XOR and multiplexer-based architecture gives a power dissipation of
661.2466 µW, whereas the architecture based on CAL (18T) dissipates 661.315 µW. Further, the adder designed
with 2N-2N2P (16T) XNOR/XOR and multiplexer approach dissipates minimum power of 642.4407 µW.
Moreover, the effect of gate length of transistor has also been considered for the evaluation of power dissipation.
By varying the gate length of the transistor from 0.35 µm to 1 µm, an improvement of 63.25%, 67.91%
and 2.56% in power consumption has been achieved using CAL (20T) XNOR/XOR, CAL (18T) XNOR/XOR
and 2N-2N2P (16T) respectively.
© 2011 IUP. All Rights Reserved.
Failure of 220 kV Overhead Power Transmission Line Due to Lightning
--
T V Gopalan and Niyas Thayyil
This paper presents the analysis of transmission line outage due to decapping of a unit of an insulator
string and falling of conductors, and suggests remedies. Failure of the 220 kV SC transmission line due to
lightning is investigated. The transmission line has functional and physical damages due to decapping of a unit of one
of the insulator strings under severe lightning. The investigations show that the damage caused by the
lightning was mainly due to poor footing resistance of the tower that is susceptible to lightning strikes, the tower
being on a hill peak.
© 2011 IUP. All Rights Reserved.
A Comparative Study
of Three Load Flow Methods
-- R P Sharma and A K Wadhwani
This paper presents a comparative study of the new constant Jacobian matrix load flow method, fast
decoupled load flow method and novel hybrid load flow method.
A mathematical model for the new constant Jacobian matrix load flow solution method in rectangular
coordinates is first presented. In this method, the usual decoupling of real and reactive power load flow equations is
not done as in the case of fast decoupled load flow method. Some reasonable assumptions are made to make
the matrix constant, thereby avoiding the necessity of computing the matrix in every iteration. The
proposed method exhibits better Convergence Reliability (CR). Numerical results from IEEE and other system
examples are presented for the comparative study of the three load flow methods for better future planning.
© 2011 IUP. All Rights Reserved.
Differential Evolution-Based Algorithm
for Congestion Management
in a Deregulated Environment
-- R Rajathy, R Gnanadass, K Manivannan and Harish Kumar
In a restructured electricity market environment, the competition in the production and consumption of
electric energy leads to the transmission network operating at or beyond one or more transfer limits. In such
a situation, the system gets congested, resulting in an increase in the cost of electricity, putting the
system security as well as reliability in danger. The selection of generators to reschedule their output for
effective management of congestion is a crucial task for the system operator. This paper presents a Differential
Evolution (DE)-based active power flow contribution factor method for the selection and rescheduling of active
power output in order to relieve congestion.
© 2011 IUP. All Rights Reserved.
A Comparative Study of 5-Bus and 14-Bus Systems with
UPFC: A Power Flow Perspective
-- Ch. Chengaiah and R V S Satyanarayana
Controlling power flow in modern power systems can be made more flexible using the recent developments
in power electronics, and computing and control technology. The Unified Power Flow Controller (UPFC) is
a Flexible AC Transmission System (FACTS) device that can control all the three system variables, namely,
line reactance, magnitude and phase angle difference of voltage across the line. This leads to sufficient
improvement in power transfer and reduction in power loss. The performance of UPFC depends on proper control
setting achievable through a power flow analysis program. This paper presents a method to control the settings
of UPFC (Feng and Nagan, 1999) through a modified Newton-Raphson-based load flow calculation.
The proposed algorithm is developed to calculate the control setting of UPFC and the power flow between
the lines after the load flow is converged. Case studies were performed on IEEE 5-bus and 14-bus systems
to observe the effectiveness of the proposed method.
© 2011 IUP. All Rights Reserved.
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