ICTACT Journal on Communication Technology

M. Madheswaran ¹, V. Jayaprakasan ²

Affiliations
1 Centre for Advanced Research, Department of Electronics and Communication, Mahendra Engineering College, IN
2 Department of Electronics and Communication, Jawaharlal Nehru Technological University, IN

Abstract

This paper briefs an implementation of different CIC filter architectures for decimation. The different decimation filter structures are implemented using cascaded integrator-comb filter to work for the down sampling ratio of 8. The prototype is designed with MATLAB Simulink model and it is converted to VHDL code using Xilinx system generator. Prototype is implemented in Virtex VXC5VLX110T- 3ff1136 FPGA kit and simulation results and device utilization reports are generated and tabulated. Finally different architectures are compared using number of used LUTs, Registers, Power consumption etc.

Keywords

FPGA – Field Programmable Gate Arrays, SRC - Sampling Rate Conversion, DDC – Digital Down Converter, CIC - Cascaded Integrator Comb Filter.

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M. Madheswaran ¹, K. R. Kavitha ²

Affiliations
1 Mahendra Engineering College, IN
2 Department of Electronics and Communication Engineering, Sona College of Technology, IN

Abstract

The theoretical estimation of dark and illumination characteristics of InGaAs quantum dot photo detector is developed and presented in this paper. The exact potential and energy profile of the Quantum Dot is computed by obtaining the solution of 3D Poisson and Schrodinger equations using Homotopy analysis. The dark current, photo current, responsivity, detectivity and efficiency of the model are calculated by considering the structural parameters Quantum Dot density, applied voltage, length of quantum dot array, number of quantum dot array, light intensity and temperature. The results obtained show that the dark current and photo current are strongly influenced by Quantum Dot density and applied voltage. The developed model is purely physics based one and overcomes the limitations of the existing analytical models. The model is validated by comparing the results obtained with the existing models.

Keywords

Quantum Dots, Poisson Equation, Homotopy Analysis, Dark Current, Photo Current.

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M. Madheswaran ¹, R. N. Shanmugasundaram ²

Affiliations
1 Centre for Advanced Research, Department of Electronics and Communication Engineering, Mahendra Engineering College, IN
2 Department of Electronics and Communication Engineering, Vidyaa Vikas College of Engineering and Technology, IN

Abstract

Low Energy Adaptive Clustering Hierarchy (LEACH) protocol is the first hierarchical cluster based routing protocol successfully used in the Wireless Sensor Networks (WSN). In this paper, various enhancements used in the original LEACH protocol are examined. The basic operations, advantages and limitations of the modified LEACH algorithms are compared to identify the research issues to be solved and to give the suggestions for the future proposed routing algorithms of wireless networks based on LEACH routing algorithm.

Keywords

LEACH, Modified LEACH, Hierarchical Cluster Based Routing, Wireless Sensor Networks (WSN).

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M. Madheswaran ¹, P. Suresh Kumar ¹

Affiliations
1 Center for Advanced Research, Department of Electronics and Communication Engineering, Muthayammal Engineering College, IN

Abstract

Modern fighter aircrafts, ships, missiles etc need to be very low Radar Cross Section (RCS) designs, to avoid detection by hostile radars. Hence accurate prediction of RCS of complex objects like aircrafts is essential to meet this requirement. A simple and efficient numerical procedure for treating problems of wide band RCS prediction Perfect Electric Conductor (PEC) objects is developed using Method of Moment (MoM). Implementation of MoM for prediction of RCS involves solving Electric Field Integral Equation (EFIE) for electric current using the vector and scalar potential solutions, which satisfy the boundary condition that the tangential electric field at the boundary of the PEC body is zero. For numerical purposes, the objects are modeled using planar triangular surfaces patches. Set of special sub-domain type basis functions are defined on pairs of adjacent triangular patches. These basis functions yield a current representation free of line or point charges at sub-domain boundaries. Once the current distribution is obtained, dipole model is used to find Scattering field in free space. RCS can be calculated from the scattered and incident fields. Numerical results for a square plate, a cube, and a sphere are presented over a bandwidth.

Keywords

Dipole Model, Method of Moment (MoM), Perfectly Electric Conductor (PEC), Radar Cross Section (RCS), Triangular Patch Model.

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M. Madheswaran ¹, C. Venkatesh ¹

Affiliations
1 Centre for Advanced Research, Department of Electronics and Communication Engineering, Muthayammal Engineering College, IN

Abstract

Ultra wideband (UWB) communication is mainly used for short range of communication in wireless personal area networks. Orthogonal Frequency Division Multiplexing (OFDM) is being used as a key physical layer technology for Fourth Generation (4G) wireless communication. OFDM based communication gives high spectral efficiency and mitigates Inter-symbol Interference (ISI) in a wireless medium. In this paper the IEEE 802.15.3a based Multiband OFDM (MB OFDM) system is considered. The pilot based channel estimation techniques are considered to analyze the performance of MB OFDM systems over Liner Time Invariant (LTI) Channel models. In this paper, pilot based Least Square (LS) and Least Minimum Mean Square Error (LMMSE) channel estimation technique has been considered for UWB OFDM system. In the proposed method, the estimated Channel Impulse Responses (CIRs) are filtered in the time domain for the consideration of the channel delay spread. Also the performance of proposed system has been analyzed for different modulation techniques for various pilot density patterns.

Keywords

UWB, OFDM, Least Square, Wireless Channel, Least Minimum Mean Square.

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