Performance analysis was carried out to find the effect of crosstalk in a WDM system. Firstly, analysis of BER
was carried out without crosstalk. Then analysis of BER with crosstalk was done. Using equation for crosstalk,
number of channels was plotted using matlab. System parameters were optimized for a particular crosstalk.
Objective of the thesis work
Performance Analysis is carried out to find the effect of crosstalk due to optical cross connect in a DWDM
system considering a WDM based optical cross connect (OXC). An analysis is carried out to find the amount of
crosstalk due to OXC. The bit error rate performance degradation due to crosstalk is evaluated for OXC
parameter and number of wavelengths per fiber. The optimum parameters such as optimum number of channels
and hops are determined.
Performance Analysis of OFDM in Combating Multipath FadingIOSR Journals
Mobile Communication system has been on high rampage for high data transmission over wireless
medium with various challenges caused by the transmission Channel. OFDM is been discovered in recent years
to deal with this problems because of its ability to elegantly cope with multipath interference. This paper
investigates the performance of different modulation schemes using M-ary Phase Shift Keying (M-PSK) and Mary
Quadrature Amplitude Modulation (M-QAM) in information transmission with OFDM technique over Ideal
channel AWGN and worst channel Rayleigh Fading channel in terms of Bits Error Rate (BER). Analysis was
made for different types of modulation schemes BPSK, QPSK, 4-QAM and 16-QAM gray coded bit mapping.
Also, a feasibility of OFDM been used to combat multipath fading was analyzed with comparison between a
single carrier technique and OFDM multicarrier technique. Variation between SNR results with respect to BER
is plotted to show the trade off differences between the modulation schemes with the result showing that OFDM
allows data transmission with minimal error over fading channel than a Single Carrier
Mitigation of non-linear four-wave mixing phenomenon in a fully optical commu...TELKOMNIKA JOURNAL
This paper aims to point out the nonlinear phenomenon occurring in coarse/dense wavelength division multiplex (C/D-WDM) systems. This phenomenon has to betaken into account during the design of the optical network itself, as wavelengthsin the optical fiber are constantly densified. The paper points out the emergence of the non-linear four-wave mixing (FWM) phenomenonand how it relates to the dispersion in the optical fiber together with the transmit power. The output of the paper is a proposed design of the system that points to the improvement of the bit error rate (BER) with a suitable choice of dispersion and suitable transmission power.
Performance Analysis of OFDM in Combating Multipath FadingIOSR Journals
Mobile Communication system has been on high rampage for high data transmission over wireless
medium with various challenges caused by the transmission Channel. OFDM is been discovered in recent years
to deal with this problems because of its ability to elegantly cope with multipath interference. This paper
investigates the performance of different modulation schemes using M-ary Phase Shift Keying (M-PSK) and Mary
Quadrature Amplitude Modulation (M-QAM) in information transmission with OFDM technique over Ideal
channel AWGN and worst channel Rayleigh Fading channel in terms of Bits Error Rate (BER). Analysis was
made for different types of modulation schemes BPSK, QPSK, 4-QAM and 16-QAM gray coded bit mapping.
Also, a feasibility of OFDM been used to combat multipath fading was analyzed with comparison between a
single carrier technique and OFDM multicarrier technique. Variation between SNR results with respect to BER
is plotted to show the trade off differences between the modulation schemes with the result showing that OFDM
allows data transmission with minimal error over fading channel than a Single Carrier
Mitigation of non-linear four-wave mixing phenomenon in a fully optical commu...TELKOMNIKA JOURNAL
This paper aims to point out the nonlinear phenomenon occurring in coarse/dense wavelength division multiplex (C/D-WDM) systems. This phenomenon has to betaken into account during the design of the optical network itself, as wavelengthsin the optical fiber are constantly densified. The paper points out the emergence of the non-linear four-wave mixing (FWM) phenomenonand how it relates to the dispersion in the optical fiber together with the transmit power. The output of the paper is a proposed design of the system that points to the improvement of the bit error rate (BER) with a suitable choice of dispersion and suitable transmission power.
Wavelet Packet based Multicarrier Modulation for Cognitive UWB SystemsCSCJournals
Orthogonal frequency division multiplexing (OFDM) is a multi-carrier modulation (MCM) scheme where the sub carriers are orthogonal waves. The main advantages of OFDM are robustness against multi-path fading, frequency selective fading, narrowband interference, and efficient use of spectrum. Recently it is proved that MCM system optimization can be achieved by applying wavelet bases instead of conventional fourier bases. Wavelet packet based MCM (WPMCM) systems have overall the same capabilities as OFDM systems with some improved features. In this research the literature and analytic schemes of WPMCM system is addressed, a wavelet packet based cognitive ultra wideband (UWB) transceiver is proposed, and performance analysis of WPMCM in different wireless multipath channels is investigated. Simulation results show a significant enhancement in terms of BER, spectral efficiency and side-lobes suppression comparing to conventional OFDM.
Implementation and Study of Universal Filtered Multi Carrier under Carrier Fr...Editor IJAIEM
Sathiyapriya N.S
PG Student, Dept. of ECE, Periyar Maniammai University Thanjavur, Tamilnadu, India
ABSTRACT
OFDM is a matured technology and applied in various wireless standards. However they are not suitable for Uplink and this
technology is replaced by SC FDMA in 4G standards. Similarly Universal Filtered Multicarrier Communication (UFMC) is
another suitable technology for Multi user Uplink and for applications like cognitive radio. UFMC is a new, non-orthogonal,
waveform designed by Alcatel Lucent Labs which provide a much more efficient way of enabling networks to serve both
broadband users and very narrowband “short data” devices such as any embedded sensor or M2M module. In UFMC the
filtering of waveform is done on a group of subcarriers. In OFDM it is done on the whole subcarriers together. This reduces
the side lobe levels, inters carrier interference (ICI) and requires reduced filter length. Moreover Internet-of-Things where
Machine-Machine communication and applications where very tight response in time requirements are needed, OFDM
miserably fails. We examine impact of carrier frequency offset on the performance of the proposed scheme and compare the
results performance of cyclic prefix based orthogonal frequency division multiplexing(CP-OFDM) system.-
Key words: ICI,CFO,OFDM,UFMC
RECONFIGURABLE OPTICAL ADD AND DROP MULTIPLEXERS A REVIEWecijjournal
Optical multiplexing is the key function of a WDM network and reliable method for data transport networks. WDM networks configured as rings/mesh along with Optical Add-Drop Multiplexers supports added flexibility, simplicity and augment the spectral efficiency. Further enhancement achieved with Reconfigurable OADM architectures, growing briskly along with automatic network management, let the transport network to acclimatize with dynamically varying environment and flexibly respond to the transport network changes. It permits single or many wavelengths to be added and/or dropped from a
transport fiber without optical-to-electrical-to-optical domain translation. Presently ROADM technology
has revolutionized optical networking and an inseparable part of modern optical communication offering huge bandwidth for data transport at minimum expense. In this view the article presents comprehensive study for numerous generations of ROADM and their architecture and persistent development
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
An Application of Green Quality Function Deployment to Designing an Air Condi...IJERA Editor
The paper tackles a systematic and operational approach to Green Quality Function Deployment (GQFD), a customer oriented survey based quality management system with regular improvement in product development. GQFD shows balance between product development and environmental protection. GQFD is not used to determine their attributes and their levels. GQFD captures what product developers “think” would best satisfy customer needs considering Environmental factor. This research used Air Conditioner as a case study for implementation of GQFD. In the design of a new Air Conditioner, apply GQFD to find out the most important parameter and functions from customer point of view and then find out Technical Characteristics. These important parameters are then put into house of quality and make relation matrix between voice of customer and Technical Characteristics. From the result of QFD applied to Air Conditioner are short out the parameter which are require modification according to voice of customer and the result has used for new design.
Cyclic Heating Effect on Hardness of AluminumIJERA Editor
Presented work discusses research results concerning the effect of the heat treatment process. Thermal fatigue which expresses repeated heating and cooling processes affect the ductility or the brittleness of the material. In this research 70 specimens of aluminum (2 mm thickness, 85 mm length, 32 mm width) are subjected to thermal fatigue at different conditions. Heating temperatures; Th = 100, 300 and 500 ° C. Number of repeated cycles; N =1 to 100. Results are evaluated then compared to each other and to that of specimens without subjected to thermal fatigue.
Performance of Light-Weight Concrete with Plastic AggregateIJERA Editor
This study is intended to explore the suitability of recycled plastics (high density polyethylene) as coarse aggregate in concrete by conducting various tests like workability by slump test, compressive strength of cube and cylinder, splitting tensile strength test of cylinder, flexural strength of R.C.C as well as P.CC. beams to determine the properties and behaviour in concrete. Effect of replacement of coarse aggregate with various percentages (0% to 40%) of plastic aggregate on behaviour of concrete was experimentally investigated and the optimum replacement of coarse aggregate was found out. The results showed that the addition of plastic aggregate to the concrete mixture improved the properties of the resultant mix.
BER Performance of OFDM-QAM over AWGN and RICAIN Channels Using Error Correct...IJERA Editor
In this paper, the performance of OFDM - QAM system by using error correcting codes (Convolutional, Reed Solomon and Interleaving) schemes that are used to encode the data stream in wireless communications using AWGN and RICIAN channels has been reported here. OFDM is presented for wireless communications we curing basic OFDM and affined modulations, as well as techniques to improve the performance of OFDM for wireless communications. Various simulations are performed to detect the best BER performance of each of the QAM system; OFDM-QAM and OFDM-QAM with Error Correction and to use the best outcomes to model the OFDM-QAM, Their effect of improving the total BER can be noticed due to the benefits of OFDM-QAM with correcting codes.
Modeling and Analysis of Wholesale Competitive Electricity Markets: A Case Fo...IJERA Editor
Electricity markets all over the world are moving towards greater reliance on competition and this has become a global trend as a method of best practice. However, before competition is introduced in electricity markets it is imperative to model and assess the behavior of the market. The assessment includes calculating the market performance indices to determine the levels of market power exploitation by the Generating Companies (GenCos) that will participate in the market. This paper presents a study on modeling and analysis of wholesale competitive electricity market for a developing country to help regulators assess and predict market behaviour. It involves modeling and simulation of the Zambian power system network in Agent-Based Modeling of Electricity Systems (AMES) using real system data to pick out critical information that enables us to assess the status of the market. The results indicate that market power exploitation is prevalent for the two largest GenCos assessed.
Wavelet Packet based Multicarrier Modulation for Cognitive UWB SystemsCSCJournals
Orthogonal frequency division multiplexing (OFDM) is a multi-carrier modulation (MCM) scheme where the sub carriers are orthogonal waves. The main advantages of OFDM are robustness against multi-path fading, frequency selective fading, narrowband interference, and efficient use of spectrum. Recently it is proved that MCM system optimization can be achieved by applying wavelet bases instead of conventional fourier bases. Wavelet packet based MCM (WPMCM) systems have overall the same capabilities as OFDM systems with some improved features. In this research the literature and analytic schemes of WPMCM system is addressed, a wavelet packet based cognitive ultra wideband (UWB) transceiver is proposed, and performance analysis of WPMCM in different wireless multipath channels is investigated. Simulation results show a significant enhancement in terms of BER, spectral efficiency and side-lobes suppression comparing to conventional OFDM.
Implementation and Study of Universal Filtered Multi Carrier under Carrier Fr...Editor IJAIEM
Sathiyapriya N.S
PG Student, Dept. of ECE, Periyar Maniammai University Thanjavur, Tamilnadu, India
ABSTRACT
OFDM is a matured technology and applied in various wireless standards. However they are not suitable for Uplink and this
technology is replaced by SC FDMA in 4G standards. Similarly Universal Filtered Multicarrier Communication (UFMC) is
another suitable technology for Multi user Uplink and for applications like cognitive radio. UFMC is a new, non-orthogonal,
waveform designed by Alcatel Lucent Labs which provide a much more efficient way of enabling networks to serve both
broadband users and very narrowband “short data” devices such as any embedded sensor or M2M module. In UFMC the
filtering of waveform is done on a group of subcarriers. In OFDM it is done on the whole subcarriers together. This reduces
the side lobe levels, inters carrier interference (ICI) and requires reduced filter length. Moreover Internet-of-Things where
Machine-Machine communication and applications where very tight response in time requirements are needed, OFDM
miserably fails. We examine impact of carrier frequency offset on the performance of the proposed scheme and compare the
results performance of cyclic prefix based orthogonal frequency division multiplexing(CP-OFDM) system.-
Key words: ICI,CFO,OFDM,UFMC
RECONFIGURABLE OPTICAL ADD AND DROP MULTIPLEXERS A REVIEWecijjournal
Optical multiplexing is the key function of a WDM network and reliable method for data transport networks. WDM networks configured as rings/mesh along with Optical Add-Drop Multiplexers supports added flexibility, simplicity and augment the spectral efficiency. Further enhancement achieved with Reconfigurable OADM architectures, growing briskly along with automatic network management, let the transport network to acclimatize with dynamically varying environment and flexibly respond to the transport network changes. It permits single or many wavelengths to be added and/or dropped from a
transport fiber without optical-to-electrical-to-optical domain translation. Presently ROADM technology
has revolutionized optical networking and an inseparable part of modern optical communication offering huge bandwidth for data transport at minimum expense. In this view the article presents comprehensive study for numerous generations of ROADM and their architecture and persistent development
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
An Application of Green Quality Function Deployment to Designing an Air Condi...IJERA Editor
The paper tackles a systematic and operational approach to Green Quality Function Deployment (GQFD), a customer oriented survey based quality management system with regular improvement in product development. GQFD shows balance between product development and environmental protection. GQFD is not used to determine their attributes and their levels. GQFD captures what product developers “think” would best satisfy customer needs considering Environmental factor. This research used Air Conditioner as a case study for implementation of GQFD. In the design of a new Air Conditioner, apply GQFD to find out the most important parameter and functions from customer point of view and then find out Technical Characteristics. These important parameters are then put into house of quality and make relation matrix between voice of customer and Technical Characteristics. From the result of QFD applied to Air Conditioner are short out the parameter which are require modification according to voice of customer and the result has used for new design.
Cyclic Heating Effect on Hardness of AluminumIJERA Editor
Presented work discusses research results concerning the effect of the heat treatment process. Thermal fatigue which expresses repeated heating and cooling processes affect the ductility or the brittleness of the material. In this research 70 specimens of aluminum (2 mm thickness, 85 mm length, 32 mm width) are subjected to thermal fatigue at different conditions. Heating temperatures; Th = 100, 300 and 500 ° C. Number of repeated cycles; N =1 to 100. Results are evaluated then compared to each other and to that of specimens without subjected to thermal fatigue.
Performance of Light-Weight Concrete with Plastic AggregateIJERA Editor
This study is intended to explore the suitability of recycled plastics (high density polyethylene) as coarse aggregate in concrete by conducting various tests like workability by slump test, compressive strength of cube and cylinder, splitting tensile strength test of cylinder, flexural strength of R.C.C as well as P.CC. beams to determine the properties and behaviour in concrete. Effect of replacement of coarse aggregate with various percentages (0% to 40%) of plastic aggregate on behaviour of concrete was experimentally investigated and the optimum replacement of coarse aggregate was found out. The results showed that the addition of plastic aggregate to the concrete mixture improved the properties of the resultant mix.
BER Performance of OFDM-QAM over AWGN and RICAIN Channels Using Error Correct...IJERA Editor
In this paper, the performance of OFDM - QAM system by using error correcting codes (Convolutional, Reed Solomon and Interleaving) schemes that are used to encode the data stream in wireless communications using AWGN and RICIAN channels has been reported here. OFDM is presented for wireless communications we curing basic OFDM and affined modulations, as well as techniques to improve the performance of OFDM for wireless communications. Various simulations are performed to detect the best BER performance of each of the QAM system; OFDM-QAM and OFDM-QAM with Error Correction and to use the best outcomes to model the OFDM-QAM, Their effect of improving the total BER can be noticed due to the benefits of OFDM-QAM with correcting codes.
Modeling and Analysis of Wholesale Competitive Electricity Markets: A Case Fo...IJERA Editor
Electricity markets all over the world are moving towards greater reliance on competition and this has become a global trend as a method of best practice. However, before competition is introduced in electricity markets it is imperative to model and assess the behavior of the market. The assessment includes calculating the market performance indices to determine the levels of market power exploitation by the Generating Companies (GenCos) that will participate in the market. This paper presents a study on modeling and analysis of wholesale competitive electricity market for a developing country to help regulators assess and predict market behaviour. It involves modeling and simulation of the Zambian power system network in Agent-Based Modeling of Electricity Systems (AMES) using real system data to pick out critical information that enables us to assess the status of the market. The results indicate that market power exploitation is prevalent for the two largest GenCos assessed.
Flow analysis of centrifugal pump using CFX solver and remedies for cavitatio...IJERA Editor
In this scholarly thesis pertinent to the working of centrifugal pump, a CFD solver namely CFX is employed in order to simulate fluid flow characteristics with well-defined constraints and boundary conditions defining the problem. Stringent solid model is meticulously prepared encompassing the present day usage and constructional features of a centrifugal pump and is constrained with various boundary conditions having fixed domain in order to evaluate plots and results. To spearhead and facilitate this analysis program a numerical approximation tool with high degree of convergence rate called ANSYS 15.0 software is used. The ASNYS software avoids tedious calculations presumably impending in the design procedure and uses ultimate numerical tool to approximate the solution of the partial differential equations associated with continuity, momentum and energy phases of a flow problem in a 3-D model. This exquisite feature of ANSYS enables designer to optimize the design procedure in an iterative manner based on the final plots of post-processing phase. In addition, the scholarly writing also constitutes the appraisal of the most debilitating and painstaking problem retarding the efficiency of the centrifugal pump known as cavitation. Possible remedies for overcoming this problem will be indirectly inferred from the various plots and figures derived from the post-processing phase of the design process.
Automatic Selection of Open Source Multimedia Softwares Using Error Back-Prop...IJERA Editor
Open source opens a new era to provide license of the software for the user at free of cost which is advantage over paid licensed software. In Multimedia applications there are many versions of software are available and there is a problem for the user to select compatible software for their own system. Most of the time while surfing for software a huge list of software opens in response. The selection of particular software which is pretty suitable for the system from a real big list is the biggest challenge that is faced by the users. This work has been done that focuses on the existing open source software that are widely used and to design an automatic system for selection of particular open source software according to the compatibility of users own system. In this work, error back-propagation based neural network is designed in MATLAB for automatic selection of open source software. The system provides the open source software name after taking the information from user. Regression coefficient of 0.93877 is obtained and the results shown are up to the mark and can be utilized for the fast and effective software search.
Summary of fracture mechanics problems analysis method in ABAQUSIJERA Editor
Fracture mechanics is the study of the strength of the materials or structures with crack and crack propagation regularity of a discipline. There are a lot of analysis function of ABAQUS, including fracture analysis. ABAQUS is very easy to use and easy to establish a model of the complicated problem. In order to effectively study of strong discontinuity problems such as crack, provides two methods of simulating the problem of cracks of ABAQUS. This paper describes the two methods respectively, and compare two methods.
Numerical Study of Star Anchor Plate Embedded in Cohesive SoilIJERA Editor
Indonesia as an archipelago country has a very long coastline about 90.000 kms. Specifically for shore and offshore, there are many buildings utilizing structures including floating deck, mooring dolphin, offshore platforms etc. Those requires a solution to maintain the stability of the structures due to the vertical movement of tides and horizontal movement of currents, wind and waves. To maintain the stability due to buoyant force, structure of anchors are needed. Various types of the anchor have been widely used such as drag, helical, anchor plate circular shape and square. This study aims to do the development of new modifications of a plate anchor type star with 4 leaves with an area of a fixed and diameter equivalent different on any variations. Ultimate pullout capacity was obtained by using numerical geomechanics analysis within finite difference method. A perfectly plastic soil model was used with a tresca yield criterion. Results are presented including break-out factors based on various anchor shapes and embedment depth. Our findings are also compared with previous numerical and empirical solutions.
Implementation of Secured Car Parking Management System Using Verilog HDLIJERA Editor
Present days usage of motor vehicles are increased day by day, it causes the pollution, traffic congestion and parking place problems. In this paper we proposed a secured car parking management system using Verilog HDL. This system has two main modules Module-1: Slot identification for parking and LCD display screens, Module-2: Security indicator will provide security to the car, if unauthorized person want to vacant the car. These modules are modeled in Verilog HDL and implemented on FPGA.
The present research work deals is to model new fore wheel bearing of agricultural machine used for ploughing which fail in regular usage. This bearing takes three formulations. They are bearing through Material Change Break Down Analysis The design is done in CATIA and Break Even Analysis is done in ANSYS. And find which one among the Bearing through Design or Bearing through Material Change is solution for the problem aimed for. Break Down Analysis is done in each of the cases to find the maximum forces to be applied on the bearings to get the maximum load that can be bared by the bearings. The objective of our project is to find the solution for the regular failure of bearings of machine through different material. Here we are using three materials i.e. steel, tungsten, zinc
Smart Prediction Of Surface Finishing Quality Of En-8 Work Piece By Ann ModelIJERA Editor
Turning is a material removal process a subtractive form of machining which is used to create parts of circular
or rotational form of desired geometry/shape by removing unwanted material. Accuracy of any process depends
on involvement of operational variables. The operating parameters that contribute to turning process are Cutting
speed, Depth of cut, Feed rate. Vibrations, tool life, tool wear, surface finish and cutting forces etc are also in
direct relation with values selected for process parameters. So to improve the efficiency of process and quality
of the product it is necessary to control the process parameters. We have considered surface roughness the
parameters with main focus as it dictates the aesthetics and sometimes ergonomical characteristics of the
product. In this work a neural network is created using feed forward back propagation technique for simulation
of the process using the Matlab Neural network toolbox. So with assurance of accuracy of the predictive
capabilities of the neural network it was then used for optimization.
Windows used in FIR Filters optimized for Far-side Stop band Attenuation (FSA...IJERA Editor
It has been proposed that the Exponential window provides better side-lobe roll-off ratio than Kaiser window
which is very useful for some applications such as beam forming, filter design, and speech processing. In this
paper the second application i.e. design of digital nonrecursive Finite Impulse Response (FIR) filter by using
Exponential window is proposed. The far-end stopband attenuation is most significant parameter when the
signal to be filtered has great concentration of spectral energy. The filter should be designed in such a way so
that it can provide better far-end stopband attenuation (amplitude of last ripple in stopband). Digital FIR filter
designed by Kaiser window has a better far-end stopband attenuation than filter designed by the other previously
well known adjustable windows such as Dolph-Chebyshev and aramaki, which are special cases of
Ultraspherical windows, but obtaining a digital filter which performs higher far-end stopband attenuation than
Kaiser window will be useful. In this paper, the design of nonrecursive digital FIR filter has been proposed by
using Exponential window. It provides better far-end stopband attenuation than filter designed by well known
Kaiser window, which is the advantage of filter designed by Exponential window. The proposed schemes were
simulated on commercially available software and the results show the close agreement with proposed theory.
A Novel Wideband Circularly Polarized Antenna for Worldwide UHF Band RFID Rea...IJERA Editor
This paper presents A Novel Wideband Circularly Polarized Antenna for Worldwide UHF Band RFID Reader
Applications with simple, compact structure. An air-substrate truncated patch antenna is used to achieve the
circularly polarized characteristic. The impedance and AR bandwidth of proposed antenna are 840-960 MHz
(VSWR less than 1.5) and (AR less than 3), respectively. Proposed antenna has a good radiation performance
with gain more than 8 dB. And it is a good choice for UHF RFID applications.
Synthesis, Electrical and Optical Properties of Nickel Sulphate Hexa Hydrate ...IJERA Editor
L-Arginine doped Nickel SulphateHexa Hydrate (NSH) single crystalswere grown by slow evaporation
techniquefor different molar concentrations, viz., (0.2 to 1 mole% in steps of 0.2).The grown crystals were
subjected to various studies.XRD data were collected from powder samples of the crystals.ACelectrical
measurementswerecarriedoutatvarioustemperaturesrangingfrom40-750C. Resultsindicate anincrease
oftheelectricalparameterswiththeincreaseoftemperature.The dielectric value suggests that the L-Arginine doped
NSH single crystal is good for microelectronic application. The UV-Vis-NIR spectral studies were performed to
analyze the optical absorption of the grown crystals in the range 200 – 1100nm. Results obtained were
presented.
Delay Optimization of Low Power Reversible Gate using MOS Transistor Level de...IJERA Editor
In Semiconductor industry has witnessed and explosive growth of integration of sophisticated multimedia base
application onto mobile electronic gadget since the last decade. The critical concern in this aspect is to reduce the
power consumption beyond a certain range of operating frequency. An important factor in the design of VLSI
circuits is the choices of reversible logic. Basically conventionally digital circuits have been implemented using
the logic gates, which were irreversible in nature only NOT gate are reversible. These irreversible gates produce
energy loss due to the information bits lost during the operation information loss occurs because the total number
of output signals generated is less than total number of input signals applied. In reversible if the input vector can
be uniquely recovered from the output vector and if there is a one to one correspondence between its input and
output logic. This paper present a new representation of existing reversible gate in MOS transistor. The MOS
transistor designing using a gate diffusion input. Those new representation of MOS transistor has a hoping future
in design of low power consumption circuits and high speed application.
Antagonism of lactic acid bacteria against pathogenic agents not related to g...IJERA Editor
Oar researchhas provedthat lactic acid bacteria possess the wide spectrum of antagonistic activity. They inhibit the
growth of not only agents of intestinal infections but also agents ofdiseases not related to gastrointestinal tract.
TNM Method Results Compared with Finite Element Analysis for a 30 KW SCIM MotorIJERA Editor
The Thermal network model (TNM) of ten node 37 thermal resistances is considered as the highly detailed one
for thermal distribution of all the TNM models. This model is reported to be the one that can take care of most
of the complexities in geometry and estimation of convective heat transfer coefficients. Results obtained for the
30 KW motor using the above TNM model have been compared with that of Finite element Analysis using
ANSYS. Listing of the MATLAB programs is presented as annexure.
Influence of Different Parameters on Heat Pipe PerformanceIJERA Editor
In electrical and electronic industry due to miniaturization of electronic components heat density increases
which, in turns increases the heat flux inside it. Scientist and many researchers are doing lot of work in this field
for thermal management of devices. Heat pipe is a device that is used in electronic circuit (micro and power
electronics), spacecraft & electrical components for cooling purpose. It is based on the principle of evaporation
and condensation of working fluid. Heat pipe made up of three main parts are evaporator, adiabatic and
condenser sections. In this working fluid vaporise at evaporator and transfers heat to condenser by adiabatic
section where heat release to surrounding. Vapour flows possible from evaporator to condenser section due to
vapour pressure difference exist between them. Use of heat pipe material, type of working fluid & its property,
wick structure, orientation, filled ratio, operating condition, dimensions of pipe has a prominent effect on heat
pipe performance. Variation of these parameters for minimum thermal resistance gives better performance.
Modeling and Simulation of Wavelength-Routed optical Networksijceronline
All-optical Wavelength Division Multiplexing (WDM) networks providing extremely large bandwidths are among the most promising solutions to the increasing need for high-speed data transport. A lightpath has a specific route and one or more wavelengths through which the information is routed from the source to the destination node. In wavelength-routed optical networks, data are transmitted solely in the optical domain along lightpaths from source to destination without being converted into the electronic form and each lightpath is allowed to use the same wavelength on all the links along its path. This restriction is known as the wavelength continuity constraint. And it leads to an issue called as blocking in networks. Optical wavelength conversion with suitable Routing and wavelength assignment (RWA) can increase the performance and capacity of optical networks by eliminating this restriction and relaxing the wavelength continuity constraint. In this research, we analyze the problem of placing a limited number of wavelength converters in a mesh network using Weighted Maximum Segment Length (WMSL) converter placement algorithm. It employs Least-Loaded Routing and First-Fit (LLR-FF) RWA algorithm. It is tested on varying number of nodes in network and its respective blocking probabilities are calculated. The proposed algorithm provides the minimum blocking probability on optimal wavelength converters placement.
Optimal Channel and Relay Assignment in Ofdmbased Multi-Relay Multi-Pair Two-...ijcnes
Efficient utilization of radio resources in wireless networks is crucial and has been investigated extensively. This letter considers a wireless relay network where multiple user pairs conduct bidirectional communications via multiple relays based on orthogonal frequency-division multiplexing (OFDM) transmission. The joint optimization of channel and relay assignment, including subcarrier pairing, subcarrier allocation as well as relay selection, for total throughput maximization is formulated as a combinatorial optimization problem. Using a graph theoretical approach, we solve the problem optimally in polynomial time by transforming it into a maximum weighted bipartite matching (MWBM) problem. Simulation studies are carried out to evaluate the network total throughput versus transmit power per node and the number of relay nodes
PERFORMANCE ANALYSIS OF ULTRAWIDEBAND WDM-ROF TECHNIQUEIAEME Publication
The demand for high capacity and wideband telecommunication channels for longdistance communication increases exponentially. The standard C and L bands have limited bandwidth and capacity. That promotes intensive research and development in wideband wavelength division multiplexing, intending to achieve low BER and highquality factors. We used four channels from various bands in the proposed wideband WDM method: O (1355 nm), E (1427 nm), L (1595 nm), and U (1595 nm) (1665 nm). We adjusted the laser intensity from -10 to 10 dBm and the optical fiber length from 20 to 80 km for the wideband WDM performance analysis. Raman preamplifiers and FBG have been incorporated into the receiver to improve the quality factor and BER of the received signal. This study established 40 Gbps data transmission over a unique ultrawideband of 310 nm. The Q factor and BER for the four channels are 7.345; 19.949; 7.831; 5.486 and 1.006e-13; 7.281e-89; 2.395e-15; 2.038e-08 at a laser power of -5 dBm/80km, respectively. The proposed technique is simulated and analyzed using optical simulation software Optisystem 13.
Performance Analysis of OFDM in Combating Multipath FadingIOSR Journals
Abstract: Mobile Communication system has been on high rampage for high data transmission over wireless medium with various challenges caused by the transmission Channel. OFDM is been discovered in recent years to deal with this problems because of its ability to elegantly cope with multipath interference. This paper investigates the performance of different modulation schemes using M-ary Phase Shift Keying (M-PSK) and M-ary Quadrature Amplitude Modulation (M-QAM) in information transmission with OFDM technique over Ideal channel AWGN and worst channel Rayleigh Fading channel in terms of Bits Error Rate (BER). Analysis was made for different types of modulation schemes BPSK, QPSK, 4-QAM and 16-QAM gray coded bit mapping. Also, a feasibility of OFDM been used to combat multipath fading was analyzed with comparison between a single carrier technique and OFDM multicarrier technique. Variation between SNR results with respect to BER is plotted to show the trade off differences between the modulation schemes with the result showing that OFDM allows data transmission with minimal error over fading channel than a Single Carrier. Keywords: OFDM, Single Carrier, AWGN, Rayleigh fading, BER, M-ary PSK, M-ary QAM
Abstract: The growing demand on wireless communication service has created the necessity to support higher data rates for multimedia services. .As next generation wireless communication networks are expected to provide broadband multimedia services such as voice, web browsing, video conferencing etc. For high data rate achievement one must enhance the capacity of the wireless communication system. The capacity of a communication system can be enhanced by using OFDM system. OFDM is commonly used for communication system due to its high transmission rate and robustness against multipath fading So as to enhance the capacity of fading channels the OFDM system are combined to form hybrid system. Capacity is the measure of maximum information that can be transmitted reliably over a channel. This paper review on different channel capacity enhancement techniques used in OFDM system is SVD (Singular Value Decomposition), water Filling algorithm.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
RECONFIGURABLE OPTICAL ADD AND DROP MULTIPLEXERS A REVIEW ecij
Optical multiplexing is the key function of a WDM network and reliable method for data transport networks. WDM networks configured as rings/mesh along with Optical Add-Drop Multiplexers supports added flexibility, simplicity and augment the spectral efficiency. Further enhancement achieved with
Reconfigurable OADM architectures, growing briskly along with automatic network management, let the transport network to acclimatize with dynamically varying environment and flexibly respond to the transport network changes. It permits single or many wavelengths to be added and/or dropped from a
transport fiber without optical-to-electrical-to-optical domain translation. Presently ROADM technology has revolutionized optical networking and an inseparable part of modern optical communication offering huge bandwidth for data transport at minimum expense. In this view the article presents comprehensive study for numerous generations of ROADM and their architecture and persistent development.
Design and Performance Study of MMDWDM Systemselelijjournal
The rising need for bandwidth created innumerable efforts from academic and industry group towards development of most efficient optical communication networks. In order to compete it numerous investigators have designed their own novel schemes. In this view the paper presents multiple modulation dense wavelength division multiplexed transmission designed links each with a total capacity of 640Gbps and with channel to channel to spacing of 100Ghz, employing multiple modulation schemes such as non return to zero rectangular, non return to zero raised cosine, return to zero rectangular, non return to zero raised cosine, return to zero soliton, return to zero Super Gaussian. The optical transmission performance characteristics like bit error rate, Q parameter at the output have been investigated by simulating different systems for a fixed transmission length of 260kilometers. Results show that transmission performance of DWDM system with non return to zero raised cosine scheme has been better with quality factor ranging from 16 to 23dB and bit error rate ranging from 10-11 to 10-40 for detected channels at selected transmission reach (260KM) and other schemes with good performance were RZ Super Guassian DWDM and RZ Soliton DWDM systems for the same transmission reach. The transmission parameter jitter have been also investigated for each system which depict that jitter effect is more severe for return to zero systems as compared to non return to zero DWDM systems. From the performance analysis for different optical links involving different modulation schemes it can be articulated that novel modulation scheme generally improves the transmission performance and must for modern optical communication systems operating at high bit rate and longer reach.
Wireless communication system with frequency selective channel OFDM modulatio...TELKOMNIKA JOURNAL
This paper introduces the design and implementation of a wireless communication system with MATLAB based on orthognal frequency division multiplexing technique (OFDM). The constructed system is consisting of transmitter, fading channel and receiver. At the transmitter, the transmitted signal first modulated with PSK modulation, and then multiplexed with OFDM technique to achieve a higher bit rates transmission. The signal was then transmitted through a frequency selective channel with 6 taps. In the receiver parity. The received faded signal processed to be de-multiplexed and de-modulated. Then, a frequency domain equalizer was adopted to remove the fading noise and the inter-symbol interference from the received signal that introduced due to the fading channel. In order to inspect the performance of the frequency equilizer, bit error rate for the overall system was calculated at the receiving point and to recover the original information signal. The simulation results of the designed system as well as the frequency equilizer showed a robustness against the frequency selective faded channel effects. The maximum obtained bit error rate was around 10-5, which means that original signal was effectively recovered.
Performance evaluation of VLC system using new modulation approachjournalBEEI
We propose a modified OFDM modulation based on multiband scheme for visible light communications (VLC) system. The method called catenated-OFDM VLC system can efficiently boost the propagation distance and combat multipath induced the inter symbol interference and inter carrier interference. Design parameters such as number of optical bands, input power, distance and data rate are varied to see their effect on the system performances. Simulation analysis is done using Optisys software Ver. 11.0. The results show that the proposed system offers a good performance at longer transmission distance of 12 m for input power of 2 dBm in case of Band=3 with 10 Gbps data rate. BER curves also indicates that the proposed system can be operated at very high data rate of 15 Gbps. This exhibits the ability of the proposed system to be one of the candidate for future optical wireless communication system.
ESTIMATION OF SYMBOL TIMING AND CARRIER FREQUENCY OFFSET USING SYNCHRONIZATI...Michael George
OFDM/OQAM is preferred as multicarrier system which operates over a multipath channel. By using the multipath channel the signal-to-noise ratio. In earlier, sub carriers are used to transmit the signals. Nowadays, FFT and DFT are used for transmitting the signals based upon the bit values. AWGN is a channel used to identify the noise produced at the output by adding the noise in the blind signal. By reducing subcarriers the noise and timing are reduced. FFT bit value was increased which provides better performance. In the multicarrier system, the error and noise was reduced by increasing the bit value.
Similar to Single Mode Optical Fiber in Rof System Using DWDM (20)
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
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• Remote control system for accessing CCR and allied system over serial or TCP.
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Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
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• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
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Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
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Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
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The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
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It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
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Single Mode Optical Fiber in Rof System Using DWDM
1. K. Nishanth Rao et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 8, (Part - 5) August 2015, pp.141-148
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Single Mode Optical Fiber in Rof System Using DWDM
K. Nishanth Rao, B. Kalpana, S.V.S Prasad
Assistant Professor, Dept of ECE, MLR Institute of Technology, Hyderabad
M. Tech Student, Dept of ECE, MLR Institute of Technology, Hyderabad
Associate Professor, HOD of ECE, MLR Institute of Technology, Hyderabad.
Abstract
Performance analysis was carried out to find the effect of crosstalk in a WDM system. Firstly, analysis of BER
was carried out without crosstalk. Then analysis of BER with crosstalk was done. Using equation for crosstalk,
number of channels was plotted using matlab. System parameters were optimized for a particular crosstalk.
Objective of the thesis work
Performance Analysis is carried out to find the effect of crosstalk due to optical cross connect in a DWDM
system considering a WDM based optical cross connect (OXC). An analysis is carried out to find the amount of
crosstalk due to OXC. The bit error rate performance degradation due to crosstalk is evaluated for OXC
parameter and number of wavelengths per fiber. The optimum parameters such as optimum number of channels
and hops are determined.
I. INTRODUCTION
OPTICAL wavelength division multiplexing
(WDM) networks are very promising due to their
large bandwidth, their large flexibility and the
possibility to upgrade the existing optical fiber
networks to WDM networks. WDM has already been
introduced in commercial systems. All-optical cross
connects (OXC), however, have not yet been used for
the routing of the signals in any of these commercial
systems. Several OXC topologies have been
introduced, but their use has so far been limited to
field trials, usually with a small number of input–
outputfibers and wavelength channels. The fact, that
in practical systems many signals and wavelength
channels could influence each other and cause
significant crosstalk in the optical cross connect, has
probably prevented the use of OXC‘s in commercial
systems. The crosstalk levels in OXC configurations
presented so far are generally so high that they give
rise to a significant signal degradation and to an
increased bit error probability. Because of the
complexity of an OXC, different sources of crosstalk
exist, which makes it difficult to optimize the
component parameters for minimum total crosstalk.
In this paper, the crosstalk with the bit error rate and
without bit error rate is calculated and compared with
each other, and the influence of the component
crosstalk on the total crosstalk is identified. We
present an analytical approximation for the total
crosstalk level in a WDM system, which makes the
component parameter optimization considerably
easier.
II. OPTICAL MULTIPLEXING
SCHEMES
A. Orthogonal frequency-division multiplexing
(OFDM):
Orthogonal frequency-division multiplexing
(OFDM) — essentially identical to Coded OFDM
(COFDM) and Discrete multi-tone modulation
(DMT) — is a frequency-division multiplexing
(FDM) scheme utilized as a digital multi-carrier
modulation method. A large number of closely-
spaced orthogonal sub-carriers are used to carry data.
The data is divided into several parallel data streams
or channels, one for each sub-carrier. Each sub-
carrier is modulated with a conventional modulation
scheme (such as quadrature amplitude modulation or
phase-shift keying) at a low symbol rate, maintaining
total data rates similar to conventional single-carrier
modulation schemes in the same bandwidth.OFDM
has developed into a popular scheme for wideband
digital communication, whether wireless or over
copper wires, used in applications such as digital
television and audio broadcasting, wireless
networking and broadband internet access.
The primary advantage of OFDM over single-
carrier schemes is its ability to cope with severe
channel conditions — for example, attenuation of
high frequencies in a long copper wire, narrowband
interference and frequency-selective fading due to
multipath — without complex equalization filters.
Channel equalization is simplified because OFDM
may be viewed as using many slowly-modulated
narrowband signals rather than one rapidly-
modulated wideband signal. The low symbol rate
makes the use of a guard interval between symbols
affordable, making it possible to handle time-
spreading and eliminate intersymbol interference
RESEARCH ARTICLE OPEN ACCESS
2. K. Nishanth Rao et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 8, (Part - 5) August 2015, pp.141-148
www.ijera.com 142 | P a g e
(ISI). This mechanism also facilitates the design of
Single Frequency Networks (SFNs), where several
adjacent transmitters send the same signal
simultaneously at the same frequency, as the signals
from multiple distant transmitters may be combined
constructively, rather than interfering as would
typically occur in a traditional single-carrier system.
B. Wavelength-Division Multiplexing (WDM):
In fiber optic communications, wavelength-
division multiplexing (WDM) is a technology which
multiplexes multiple optical carrier signals on a
single optical fiber by using different wavelengths
(colours) of laser light to carry different signals. This
allows for a multiplication in capacity, in addition to
enabling bidirectional communications over one
strand of fiber. This is a form of frequency division
multiplexing (FDM) but is commonly called
wavelength division multiplexing.
The term wavelength-division multiplexing is
commonly applied to an optical carrier (which is
typically described by its wavelength), whereas
frequency-division multiplexing typically applies to a
radio carrier (which is more often described by
frequency). However, since wavelength and
frequency are inversely proportional, and since radio
are both forms of electromagnetic radiation, the two
terms are equivalent in this context.
A WDM system uses a multiplexer at the
transmitter to join the signals together, and a
demultiplexer at the receiver to split them apart. With
the right type of fiber it is possible to have a device
that does both simultaneously, and can function as an
optical add-drop multiplexer. The optical filtering
devices used have traditionally been etalons, stable
solid-state single-frequency Fabry-Perot
interferometers in the form of thin-film-coated
optical glass.
As explained before, WDM enables the
utilization of a significant portion of the available
fiber bandwidth by allowing many independent
signals to be transmitted simultaneously on one fiber,
with each signal located at a different wavelength.
Routing and detection of these signals can be
accomplished independently, with the wavelength
determining the communication path by acting as the
signature address of the origin, destination or routing.
Components are therefore required that are
wavelength selective, allowing for the transmission,
recovery, or routing of specific wavelengths.
In a simple WDM system each laser must emit
light at a different wavelength, with all the lasers
light multiplexed together onto a single optical fiber.
After being transmitted through a high-bandwidth
optical fiber, the combined optical signals must be
demultiplexed at the receiving end by distributing the
total optical power to each output port and then
requiring that each receiver selectively recover only
one wavelength by using a tunable optical filter. Each
laser is modulated at a given speed, and the total
aggregate capacity being transmitted along the high-
bandwidth fiber is the sum total of the bit rates of the
individual lasers. An example of the system capacity
enhancement is the situation in which ten 2.5-Gbps
signals can be transmitted on one fiber, producing a
system capacity of 25 Gbps. This wavelength-
parallelism circumvents the problem of typical
optoelectronic devices, which do not have
bandwidths exceeding a few gigahertz unless they are
exotic and expensive. The speed requirements for the
individual optoelectronic components are, therefore,
relaxed, even though a significant amount of total
fiber bandwidth is still being utilized.
Figure .1: Diagram Of A Simple WDM System
C. DWDM System
Dense wavelength division multiplexing, or
DWDM for short, refers originally to optical signals
multiplexed within the 1550 nm band so as to
leverage the capabilities (and cost) of erbium doped
fiber amplifiers (EDFAs), which are effective for
wavelengths between approximately 1525-1565 nm
(C band), or 1570-1610 nm (L band). EDFAs were
originally developed to replace SONET/SDH optical-
electrical-optical (OEO) regenerators, which they
have made practically obsolete. EDFAs can amplify
any optical signal in their operating range, regardless
of the modulated bit rate. In terms of multi-
wavelength signals, so long as the EDFA has enough
pump energy available to it, it can amplify as many
optical signals as can be multiplexed into its
amplification band (though signal densities are
limited by choice of modulation format). EDFAs
therefore allow a single-channel optical link to be
upgraded in bit rate by replacing only equipment at
the ends of the link, while retaining the existing
EDFA or series of EDFAs through a long haul route.
Furthermore, single-wavelength links using EDFAs
can similarly be upgraded to WDM links at
reasonable cost. The EDFAs cost is thus leveraged
across as many channels as can be multiplexed into
the 1550 nm band.
3. K. Nishanth Rao et al. Int. Journal of Engineering Research and Applications www.ijera.com
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Figure.2: Multichannel DWDM transmission system
D. Transponder
Transponders receive optical signals and send
them out carrying digital information at predefined
wavelengths in accordance with the ITU-T guidelines
(see reference table on pages 75 to 79) . A single
channel transmitter typically consists of a high power
distributed feedback (DFB) laser followed by a
modulator and power amplifier (also referred to as a
post-amplifier or booster). Direct modulation of the
laser is only possible up to 2.5 Gbps. For higher
transmission rates as a result of laser chirp, an
external modulator must be used. DFB lasers offer
greater precision than Fabry-Perot (FP) lasers, the
latter of which emits harmonics close to the main
peak rendering them unsuitable for DWDM systems.
In DWDM systems both fixed and uneable laser
sources can be utilized. In networks with dense
channel spacing, transponder temperature must be
stabilized. This can be enabled with the use of
thermo-electric coolers.
E. Multiplexer (MUX)
MUX are deployed in DWDM systems to
combine the signals at different wavelengths onto a
single fiber through which they then travel
simultaneously. Each wavelength carries its own
information and represents a channel. An ideal MUX
requires uniformly high transmission across the
passband with a very high drop at the edge.
F. Fiber
The fiber is one of the most critical components
of a DWDM system as it provides the physical
transportation medium. Optical fibers consist of both
core and cladding. The core is the inner, light-guiding
section and is surrounded by the cladding. As the
refractive index of the core is higher than that of the
cladding, light entering it at an angle – or numerical
aperture – is fully reflected (almost 100 percent) off
the core/cladding boundary and propagates down the
length of the fiber. Optical fibers can be divided into
multimode and singlemode fibers, each
approximately the size of a human hair, with an outer
diameter of 125 μm. Core size however differs. The
diameter of multimode fibers range from between 50
μm and 62.5 μm, whilst for singlemode fibers it is
between 7 and 10 μm. Light propagates down the
fiber core in a stable path known as a mode. In
multimode fibers, multiple paths arise making them
unsuitable for use in long haul DWDM transmission.
In DWDM systems the fibers can be used either
unidirectionally (signals transmitted in one direction
only per fiber) or bi-directionally (signals traveling in
both directions).
G. Amplifier
Amplifiers boost signals traveling down a fiber
so they can cover longer spans. In the early stages of
fiber optic telecommunications, lasers emitted
relatively low power which led to the signal having to
be frequently electrically regenerated (figure 7).
These amplifiers receive the optical signal and
convert it into an electrical signal (O/E conversion)
which is then reshaped, retimed and amplified again.
This is the so called 3R regenerator. Finally, the
signal is converted back to an optical signal (E/O
conversion). Optical fiber amplifiers (OFAs) can be
used to provide a more economical solution. These
can work solely in the optical domain, performing a
1R (optical reamplification only) regeneration. OFAs
simultaneously amplify each wavelength of the
DWDM signal without the need for demultiplexing
and remultiplexing. One major advantage of OFAs is
their transparency to signal speed and data type.
Three types of OFAs are deployed in DWDM
systems: erbium doped fiber amplifier (EDFA),
semiconductor optical amplifiers (SOA) and Raman
fiber amplifiers (RFA). In DWDM systems, the
multiplexed signal has to be demultiplexed before
each channel is regenerated, emitted by a laser and
then multiplexed again. This is a process which is
both complex and expensive.
H. Demultiplexer (DEMUX)
DEMUXs unscramble multiplexed channels
before they are fed into their corresponding receivers.
They work similarly to MUXs but operate in the
reverse direction. It is common to preamplify optical
signals before they are separated by the optical filters
of the demultiplexer. The performance of a MUX or
DEMUX is related to its capability to filter each
incoming signal. The Bragg grating is currently the
most popular technique used in DWDM systems.
I. Receiver
Receivers are used to convert optical signals into
electrical signals. The light pulses transmitted over
the optical fiber are received by a light sensitive
device known as a photo diode which is made of
semi-conductor material.
J. Limitations of WDM
Crosstalk will be one of the major limitations for
the introduction of OXC in all optical networks. In
4. K. Nishanth Rao et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN: 2248-9622, Vol. 5, Issue 8, (Part - 5) August 2015, pp.141-148
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this paper the influence of the components on the
total OXC crosstalk is investigated.
K. Crosstalk
Crosstalk occurs in devices that filter and
separate wavelengths. A small proportion of the
optical power that should have ended up in a
particular channel(on a particular filter output)
actually ends up in an adjacent (or another)
channel.Crosstalk is critically important in WDM
systems. When signals from one channel arrive in
another they become noise in the other channel. This
can have serious effects on the signal-to-noise ratio
and hence on the error rate of the system. Crosstalk is
usually quoted as the ―worst case‖ condition. This is
where the signal in one channel is right at the edge of
its allowed band. Crosstalk is quoted as the
loss in dB between the input level of the signal and
its (unwanted) signal strength in the adjacent channel.
A figure of 30 dB is widely considered to be an
acceptable level for most systems.
Figure. 3:Defination of Cross talk
L. Types of crosstalk
Different kinds of crosstalk exist, depending on
their source. First one has to make a distinction
between interband crosstalk and intraband crosstalk.
Interband crosstalk: Interband crosstalk is the
crosstalk situated in wavelengths outside the channel
slot (wavelengths outside the optical bandwidth).
This crosstalk can be removed with narrow-band
filters and it produces no beating during detection, so
it is less harmful. In a WDM networks, interband
crosstalk appears from channels of different
wavelengths.
Intraband Crosstalk: The crosstalk within the same
wavelength slot is called intraband crosstalk.(fig 1.2).
It cannot be removed by an optical filter and
therefore accumulates through the network. Since it
cannot be removed, one has to prevent the crosstalk.
In this paper intraband crosstalk is studied since the
network performance will be limited by this kind of
crosstalk. Intraband crosstalk occurs when the signal
and the interferer has the closely-valued wavelengths.
Intraband however, can be coherent or incoherent
crosstalk. If the signal crosstalk mixing takes place
within the laser coherence length, then intraband
crosstalk is defined as coherent. Otherwise incoherent
crosstalk will appear.
Figure.5: Interband and Intraband Crosstalk
Moreover, within the intraband crosstalk, a
distinction between incoherent and coherent crosstalk
has to be made. These types of crosstalk are not well
defined in literature and therefore a definition is
given here. To make a distinction between both types
of intraband crosstalk one has to look at the
consequences. The interference of the signal channel
and the crosstalk channel at the detector results in a
beat term.
III. ANALYSIS OF CROSSTALK IN
WDM SYSTEM
Firstly the block diagrams representing the
system block diagram and WDM system with Hops.
Secondly, analysis of Bit Error Rate without
Crosstalk, which is in ideal case, is given. Then
analysis of Bit Error Rate with Cross talk using
equations in both the cases is given.
A. WDM system block diagram
Figure.6: Sample WDM System
The above block diagram shows a simple WDM
system. Here L numbers of signals are multiplexed in
a channel in a multiplexer from transmitters. N
number of channels are going through Optical Cross
connect and each channel are demultiplexed using a
demultiplexer and the receiver receives the desired
signal.
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IV. SYSTEM BLOCK DIAGRAM WITH
HOPS
The above diagram shows a WDM system block
diagram with hops. Here three hops are shown. L
number of signals are multiplexed and passed
through a optical fiber. Which is demultiplexed to get
the desired signal and a new signal is multiplexed by
the transmitter. The signal passes through optical
fiber again. This way hops are used.
A. Block diagram of optical cross connect
Figure.7: Schematic illustration of conventional OXC
node
The above diagram shows an optical cross
connect where M input fibers are coming. The cross
connect switches the signal to the desired location to
pass on the other side to be demultiplexed.
B. Block diagram of oxc crosstalk
Figure.8: Schematic illustration of conventional OXC
node
The above diagram shows the crosstalk in the
Optical switch. In the switch, signal from input 1 is
connected with output 3. And signal from input 3 is
connected to output 1. But it can be seen that in
output 3, a little portion of input 3 has entered along
with the signal 1. Similarly at output 1 a little portion
of input 1 has entered along with the signal 3. this
unwanted portion of signal that enters in the output of
the Optical Cross connect is the crosstalk due to
OXC.
C. Analysis of Bit Error Rate without Crosstalk
Bit Error Rate can be calculated with and
without Crosstalk using some equations. In this
section the ideal case is shown. So Crosstalk is taken
to be zero. Equation for crosstalk is given is the next
section. Bit Error Rate: The number of bit errors that
occur within the space of one second. This
measurement is one of the prime considerations in
determining signal quality. The higher the data
transmission rate the greater the standard.
The BER is an indication of how often data has
to be retransmitted because of an error. Too high a
BER may indicate that a slower data rate would
actually improve overall transmission time for a
given amount of transmitted data since the BER
might be reduced, lowering the number of packets
that had to be resent.
For most practical WDM networks, this
requirement of BER is 10
-12
(~ 10
-9
to 10
-12
), which
means that a maximum one out of every 10
12
bits can
be corrupted during transmission. Therefore, BER is
considered an important figure of merit for WDM
networks; all designs are based to adhere to that
quality.
BER in WDM system is calculated by the equation:
BER =. 5 erfc (Q/√2) (eq. 1) Here Q is a function
proportional to the receiver signal-to-noise ratio
(SNR).
D. Analysis of Bit Error Rate with Crosstalk
In practical case zero crosstalk is not possible. So
BER is calculated with equation 1 taking in the value
of σc
BER =. 5 erfc (Q/√2) (eq. 1)
Here Q is a function proportional to the receiver
signal-to-noise ratio (SNR).
It is expressed as:
Q = (Rd * Ps) ^2/√(σase^2 + σc^2)
V. RESULTS AND DISCUSSION
BER or Bit Error Rate is plotted as a function of
input power (Pin) in dbm in Figure: 1 Here the value
of Rb(bit rate) is 10GHz. The Pin is taken from range
-8 dbm to 100 dbm. The resulting graph of BER VS
Pin is plotted bellow. It is seen that without crosstalk
the BER increase with increase in Pin.
Figure 9
This is the plot of BER vs power in dbm for
different bandwidths. Here for without crosstalk
different values of bandwidth(B) is taken and has
been shown in graph. The input power is taken from
range -8 dbm to -1 dbm. Then the corresponding
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values of BER are plotted against Pin for the
corresponding different values of B.
Figure.10: BER vs input power for different
Bandwidth.
The resulting graph of BER VS Pin is plotted
above. We have plotted this graph for three different
bandwidths. It is seen that the BER increases with
increase in Pin. It is also shown that to use more
bandwidth we need more input power. For example,
when we use 4*Rb as our bandwidth, we need -
1.2dbm power where we need 0.1 dbm input power
to use 6*Rb as bandwidth. At the same time BER
also increase with increase in bandwidth.
A. BER with Crosstalk
BER or bit error rate is plotted as a function of input
power (Pin) in dbm in Figure: 3.
Figure.11: BER vs Input power in dbm
In this graph we have plotted BER against Input
power in dbm when crosstalk is available. Now we
have plotted the graph of BER against input power in
dbm for different crosstalk. Different values of
crosstalk have been taken here for a fixed bandwidth
and analysis the graphs for different crosstalk. The
input power is taken from range -5dbm to 20dbm.
Figure 12: BER vs input power in dbm for different
crosstalk.
Here we show that BER increase for increasing
crosstalk. For using more input power we get more
crosstalk. For example, when 1.8 dbm is used as
input power, the crosstalk is and for 9.1dbm input
power, crosstalk is. At the same time BER is also
increasing.
Figure below shows Crosstalk plotted against
number of channel using in WDM system. The input
power is taken from the range -8dbm to 20 dbm.
Effective adjacent and non adjacent both are taken
0.5. We have plotted this graph for 2 hoops and 10
channels.
Figure 13: crosstalk vs number of channel
From this graph it can be said that crosstalk
increase if we use more channels. The graph of
crosstalk vs number of channel is plotted for different
number of hops. In this graph we have changed the
value of M for the same input power, which is -8dbm
to 20 dbm and for 10 channels.
Figure 14: crosstalk vs number of channels
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It can be said that if we increase the number of
hop then crosstalk also increases. Another way it can
be analyzed that for a fixed number of crosstalk if we
use more hops, the number of channel decrease and
in another way we can use more channels for less
hops. Now from the figure 4, for one bit error rate we
can find the power penalty from the input power.
Power penalty is the difference between two powers.
So for calculating power penalty we need to calculate
the difference of input power with crosstalk from the
power without crosstalk.Power penalty vs crosstalk is
plotted here.
Figure 15: power penalty vs crosstalk
From this graph we can be able to find out the
crosstalk for different power penalty.
Figure 16: power penalty vs crosstalk.
For example, it can be said that for 8.1 power
penalty relative crosstalk is -40 db, which is 0.0004.
in this way we can find crosstalk for a given power
penalty. After finding the amount of crosstalk we can
find the number of channels and number of hops can
be used for that particular crosstalk from figure 6
which is crosstalk vs number of channels.
For this graph we are able to find out the number
of channels and hops for related crosstalk. For
example for power penalty 8.1db we got the
corresponding crosstalk to be -40db which is 10^(-4).
From the above graph, we can find combinations of
hops and channels. Here, the combinations are :
Hoops Channels
6 9.6 = 10(approx.)
10 8.7 = 9 (approx.)
14 8.2 = 8 (approx.)
18 7.8 = 8 (approx.)
22 7.4 = 7 (approx.)
26 7.2 = 7 (approx.)
Numbers of channel are plotted against number
of hops.
This graph can be plotted manually too. Which is
given below. This graph shows different
combinations of hops and channels for a crosstalk 10
^ (-4) which we got for power penalty 8.1 db. From
this graph any combination can be used for this
power penalty. Similarly, we can plot a graph for
hops and channels for any power penalty and
corresponding crosstalk. Therefore a relationship
between hops and channels is established using this
graph.
VI. CONCLUSION
In this thesis paper, we have used some basic
equations to optimize the relation between hoops and
channels. No new equation were derived or used to
form this relationship. The graph was plotted
manually using the graphs plotted with the basic
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equations of BER and Crosstalk in matlab software.
At first a graph for BER vs. Pin was plotted using
BER equation. Then a graph of crosstalk vs. number
of channels was plotted for different number of hops.
From this graph power penalty was found out. This
power penalty was used to plot a graph of power
penalty vs. crosstalk. From this graph we have taken
a particular crosstalk. And from the graph of
crosstalk vs. channel, the combination of hoops and
channels were found out. Which were plot manually
to get the final graph. The graphs are shown in the
Result section.
In this final graph, we have shown that for a
particular Power Penalty, combination of hoops and
channels can be plotted. The user can use any
combination as required by the system. Hence, we
can conclude that by this process we can find number
of hoops and channels for a given Power penalty.
FUTURE WORK
Further research can be carried out to evaluate
the performance of a WDM network with OXC using
different topologies of the OXC and to find a
topology with optimum system performance. Work
can be carried out to evaluate the performance of a
WDM system with bi-directional OXC and find the
limitations due to crosstalk and optimum system
parameters. Work can be carried out with precoding
techniques to minimize the effect of Bit noise due to
crosstalk and signal in a WDM system.
REFERENCES
[1]. ‗Performance Limitations of Optical Cross
Connect without Wavelength Converter due
to Crosstalk‘ by M. S, Islam, S.P.
Majumder, Ngee Thiam Sim
[2]. ‗Crosstalk in WDM Communication‘ by
Idelfonso Tafur Monry, EdwardbTangdiong
ga
[3]. ‗Analysis of Signal Distortion and Crosstalk
Penalties Induced By Optical Filters in
Optical Networks.‘ By John D. Downie, A.
Boh Ruffin
[4]. ‗Optical Crosstalk in Fiber Radio WDM
Networks‘ by David Castleford,
Ampalavanapillai Nirmalathas, Dalama
Nobak, Rodney S. Tucke.