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Panda S.,Kalam Institute of Technology | Sarangi A.,Siksha ‘O’ Anusandhan University
AEU - International Journal of Electronics and Communications | Year: 2014

This paper makes use of shuffled frog-leaping algorithm (SFLA) as a training algorithm to train multi-layer artificial neural network (ANN). Next, The SFLA ANNs are used for channel equalization. We, in this paper, also introduce SFLA for channel equalization that is formulated as an optimization problem. In short, this paper introduces a novel strategy for training of ANN and also proposes two novel approaches for channel equalization problem using shuffled frog-leaping algorithm (SFLA). The proposed strategies are tested both in time-invariant and time varying channels and interestingly yield better performance than contemporary approaches as evidenced by simulation results. © 2014 Elsevier GmbH. All rights reserved.


Panda S.,Kalam Institute of Technology | Mohapatra P.K.,Orissa Engineering College, Bhubaneswar
Applied Soft Computing Journal | Year: 2015

This paper deals with the problem of equalization of channels in a digital communication system. In the literature, arti.cial neural network (ANN) has been increasingly used for the said problem. However, traditional methods of ANN training fall short of desired performance in the problem of equalization. In this paper, we propose a recently proposed training method for ANN for the problem. This training uses directed search optimization (DSO) as a trainer to neural networks. Then, we apply the same to the problem of nonlinear channel equalization and in that way, this paper introduces a novel strategy for equalization of nonlinear channels. Proposed method of channel equalization performs better than contemporary equalization methods used in the literature, as evident from extensive simulation results presented in this paper. © 2014 Elsevier B.V. All rights reserved.


Subudhi P.K.,Maharaja Institute of Technology | Palo S.,Kalam Institute of Technology | Sahu T.,Berhampur University
Superlattices and Microstructures | Year: 2012

We analyze the strain induced changes in the low temperature multisubband electron mobility mediated through the intersubband interactions in a pseudomorphic GaAs/In xGa 1-xAs coupled double quantum well structure. We consider the non-phonon scattering mechanisms and study the effect of strain on them. We show that strain reduces the mobility due to ionized impurity (imp-) scattering μ imp but enhances the mobility due to interface roughness (IR-) scattering μ IR. For alloy disorder (AL-) scattering as long as the lowest subband is occupied, the effect of strain enhances the mobility μ AL. However, once the second subband is occupied, there is almost no change, rather decrease in μ AL for larger well widths. It is gratifying to note that for single subband occupancy, the effect of strain enhances the total mobility μ. On the other hand, for double subband occupancy, initially there is almost no change, but with increase in well width the total mobility reduces. We vary the In composition x from 0.15 to 0.2 and 0.25 and the barrier width between the two wells to analyze their effects on the mobility which shows interesting results. Our study of multisubband mobility can be utilized for the low temperature device applications. © 2012 Elsevier Ltd. All rights reserved.


Sahu T.,Indian National Institute of Engineering | Palo S.,Kalam Institute of Technology | Sahoo N.,Berhampur University
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2012

We analyze the enhancement of multisubband electron mobility due to an external electric field in a pseudomorphic GaAs/In xGa 1-xAs coupled double quantum well structure. An electric field, applied perpendicularly to the interface plane, changes the potential energy profile of the structure. This change alters the energy level, wave function as well as the occupation of a subband. By varying the field, the system can be transformed from double subband occupancy to single subband occupancy resulting in an enhancement of the mobility due to the suppression of the intersubband effects. We consider scatterings due to the ionized impurities, interface roughness and alloy disorder and study the variations in the intrasubband and intersubband scattering matrix elements as a function of the electric field. The novelty of our work is the analysis of the effect of structure parameters like well width, barrier width and doping concentration on the field dependent multisubband electron mobility. We show that a large enhancement in mobility can be achieved through application of an external electric field by suitably choosing the material parameters. © 2012 Elsevier B.V.


Palo S.,Kalam Institute of Technology | Sahoo N.,Berhampur University | Sahu T.,Indian National Institute of Engineering
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2014

We analyse the low temperature multisubband electron mobility in an Al xGa1-xAs parabolic quantum well in which the side barriers are delta doped with Si. We change the doping profile and other structure parameters to study their effect on the electron mobility μ through intersubband effects. We show that with increase in surface electron density Ns the mobility due to ionized impurity (Imp-) scattering μImp increases while due to alloy disorder (Al-) scattering μAl decreases. As long as single subband is occupied, μ is governed by both Imp- and Al-scatterings. Once double subband is occupied, μ is determined by Imp-scattering only through intersubband effects. We show that increase in μ with increase in spacer width at a certain well width can be enhanced by increasing Ns. Further we show that the mobility enhances by reducing the curvature of the parabolic potential. The mobility is more when there is doping in both of the side barriers compared to single side doping. Our results of electron mobility in a parabolic quantum well can be utilized for low temperature device application. © 2014 Elsevier B.V.


Palo S.,Kalam Institute of Technology | Sahoo N.,Berhampur University | Sahu T.,Indian National Institute of Engineering | Panda A.K.,Indian National Institute of Engineering
2014 International Conference on Advances in Electrical Engineering, ICAEE 2014 | Year: 2014

We analyze the enhancement of multisubband electron mobility in delta-doped AlxGa1-xAs parabolic quantum well structures. We show that mobility is considerably enhanced in a parabolic quantum well compared to that in a square quantum well due to shifting of subband electron wave functions towards the centre of the well through the influence of the parabolic structure potential. We analyse the interplay of different scattering mechanisms on subband mobility mediated by intersubband interactions which leads to interesting results. © 2014 IEEE.


Mishra B.,International Institute of Information Technology Bhubaneswar | Panigrahy S.K.,National Institute of Technology Rourkela | Charan Tripathy T.,Kalam Institute of Technology | Jena D.,International Institute of Information Technology Bhubaneswar | Jena S.K.,National Institute of Technology Rourkela
Proceedings of the 2011 World Congress on Information and Communication Technologies, WICT 2011 | Year: 2011

In this paper, a secure and efficient protocol for vehicular ad hoc networks has been proposed that ensures both message authentication and privacy preservation. As safety related message may contain life critical information, it is a necessity that the sender as well as the message are authentic. The proposed scheme is based on a secure elliptic curve digital signature algorithm approach. The proposed scheme supports conditional privacy, where the user's location can be revealed at the willingness of the user. Apart from this, the scheme is secure against attacks like DoS, Sybil and Grey/Black Hole attacks. From the comparison with previously proposed schemes, it is found that the proposed scheme as based on elliptic curve discrete logarithmic problem, outperforms existing algorithms based on integer factoring and discrete logarithmic problem. © 2011 IEEE.


Sarangi A.,Siksha ‘O’ Anusandhan University | Mahapatra R.K.,Kalam Institute of Technology | Panigrahi S.P.,Korea Institute of Science and Technology
Expert Systems with Applications | Year: 2011

This paper proposes two hybrid algorithms, one between particle swarm optimization (PSO) and differential evolution (DE) and second between PSO and quantum infusion (QI). This paper applies these algorithms for digital filter design. PSO algorithm is used as a basis for comparison. Extensive simulation results show the superiority of algorithms developed in this paper. © 2011 Elsevier Ltd. All rights reserved.


Sahu A.K.,Kalam Institute of Technology | Singh S.S.,KIIT University
International Journal of Engineering and Technology | Year: 2012

Wireless communication using Multiple-Input Multiple-Output (MIMO) links has emerged as one of the most significant breakthroughs in modern communications because of the huge capacity and reliability gains promised even in worst fading environment. This paper presents an overview of some important behaviors of MIMO systems under Rayleigh channel environments. This work describes the basic ideas of MIMO transmission systems and focused and investigated the BER performance. All analysis was performed under ideal identical independent fading conditions by the use of MATLAB. At the initial stage of the work we related the SNR and the error performance of MIMO systems with the diversity schemes, in the later part of the paper, implementations of different equalizers are also verified for the improvement of the BER performance. Each chapter is rounded by a number of simulations to deepen the understanding of the performance with the use of multiple antennas and equalizers in wireless communication over Rayleigh wireless radio channels. MIMO fading channels are correlated to observe mutual coupling between antenna elements. Receiver diversity is analyzed especially with the Maximal Ratio Combining(MRC) technique and fair comparison is done with Equal Gain Combining(EGC) and Selection- Combing(SC). Further study is done with integration of Maximum Likelihood (ML), Maximum Mean Square Equalization(MMSE) and Zero Forcing(ZF). All the results obtained are simulated by using the MATLAB, under Rayleigh channel conditions.


Sahu T.,Indian National Institute of Engineering | Palo S.,Kalam Institute of Technology | Panda A.K.,Indian National Institute of Engineering
Journal of Applied Physics | Year: 2013

We analyze the low temperature multisubband electron mobility in Al xGa1-xAs-GaAs parabolic double quantum well structures in which the outer barriers are delta doped with Si. The structural parabolic potential, obtained from gradual variation of the alloy fraction x (from 0 to xp), partly compensates the triangular like potential profile near the outer interfaces inducing the electrons to move towards the centre of the wells. We study the effect of interplay of ionized impurity (II) scattering and alloy disorder (AD) scattering on the subband mobility. We show that when single subband is occupied both II- and AD-scatterings govern the mobility. However, once second subband is occupied, the mobility is influenced by II-scattering mediated by intersubband effects. It is gratifying to show that the mobility is considerably enhanced in parabolic double quantum wells (0.3 ≥ xp > 0) compared to the square double quantum well structures (xp = 0) at large well widths where double subband is occupied. By increasing the electron density (Ns), the enhancement increases further. We also show that in case of a parabolic single quantum well structure large enhancement in mobility is obtained compared to that of square single quantum well structure as long as single subband is occupied, unlike the double quantum well systems. Our results of mobility in parabolic double quantum wells can be utilized for low temperature device applications. © 2013 American Institute of Physics.

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