The document analyzes the characterization of physical layer impairments on optical fiber transmission systems. It discusses both linear and nonlinear impairments such as chromatic dispersion, polarization mode dispersion, fiber attenuation, and crosstalk. Linear impairments are modeled using an analytical linear channel model. The quality of transmission is highly affected by these physical layer impairments. Characterization of impairments is important for developing digital signal processing techniques to compensate for them and improve throughput.
Signal quality of dispersion managed quasi linear high bit rateIAEME Publication
This document summarizes a research paper that investigates the performance of a quasi-linear optical fiber transmission system using two dispersion management models: DCF-SMF and SMF-DCF. Simulation results show that the SMF-DCF model provides better signal quality than the DCF-SMF model. Specifically, the SMF-DCF model allows transmission over longer distances, with lower transmission power, at higher bit rates, and is more tolerant of residual dispersion than the DCF-SMF model. The research aims to improve the design of high-capacity optical transmission systems operating from 40-160 Gbps.
Este en un informe en ingles que muestra el impacto que tiene las ondas 5G en la biología humana, se recomienda traducirlo para poder entenderlo en sub totalidad
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
This document reviews the OFDM-IDMA technique and its implementations. It begins with introductions to OFDM and OFDM-IDMA. OFDM-IDMA uses interleaving instead of spreading sequences to distinguish users, avoiding bandwidth expansion without coding gain. The document then summarizes various implementations of OFDM-IDMA using discrete wavelet transform, MIMO systems, and implementations on FPGA. It also discusses implementations using finite Radon transform and discrete wavelet transform. Finally, it proposes future work on implementing OFDM-IDMA using Radon transform and performing comparative analysis of wavelet, FFT, and Radon-based OFDM-IDMA systems over AWGN and Rayleigh fading channels.
Simulation of Few Mode Fiber Communication System Using Adaptive Recursive le...rahulmonikasharma
The document summarizes research on simulation of few mode fiber communication systems using adaptive algorithms. It discusses using the recursive least squares (RLS) algorithm to improve convergence speed but with increased complexity compared to frequency domain least mean square (FD-LMS) algorithms. The FD-LMS algorithm is used as a reference. A step size controller is also proposed to improve convergence behavior. Previous studies on adaptive frequency domain equalization schemes and use of normalized frequency domain adaptive filters to increase convergence speed over long transmission distances are also summarized.
1) The document analyzes the effect of intercarrier interference (ICI) on single carrier orthogonal frequency division multiplexing (SC-OFDM) systems.
2) It proposes a novel magnitude-keyed modulation scheme that provides SC-OFDM immunity to ICI. This outperforms other modulation schemes like OFDM, SC-OFDM, and MC-CDMA that use phase shift keying or quadrature amplitude modulation in environments with severe ICI.
3) The analysis shows that the effect of ICI on SC-OFDM signals is simply a phase offset on each data symbol, whereas ICI introduces interference between subcarriers for OFDM. Therefore, SC-OFDM has significantly better performance
Integrated DWDM and MIMO-OFDM System for 4G High Capacity Mobile Communicatio...CSCJournals
This document describes a simulation of an integrated 64-channel dense wavelength division multiplexing (DWDM) system with multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) technology for high-capacity 4G mobile communication. The DWDM transmitter is designed to transmit baseband non-return-to-zero signals over fiber at 10 Gbps per channel for a total of 640 Gbps. After transmission over fiber with dispersion compensation, the signals are input to the MIMO-OFDM system. Space-time block coding is used to provide diversity in the MIMO-OFDM system. The performance is analyzed in terms of bit error rate with signal-to-noise ratio, achieving a desirable B
1) The document describes a study on improving channel capacity for radio propagation in ocean vessels using MIMO-OFDM systems.
2) It proposes using 16-QAM modulation, Alamouti SFBC coding, and a Rayleigh fading channel model to increase channel capacity and signal reliability despite metal reflections.
3) Simulation results show MIMO techniques like spatial multiplexing and Alamouti coding improve channel capacity and lower bit error rates compared to SISO in engine room and coupled compartment environments.
Signal quality of dispersion managed quasi linear high bit rateIAEME Publication
This document summarizes a research paper that investigates the performance of a quasi-linear optical fiber transmission system using two dispersion management models: DCF-SMF and SMF-DCF. Simulation results show that the SMF-DCF model provides better signal quality than the DCF-SMF model. Specifically, the SMF-DCF model allows transmission over longer distances, with lower transmission power, at higher bit rates, and is more tolerant of residual dispersion than the DCF-SMF model. The research aims to improve the design of high-capacity optical transmission systems operating from 40-160 Gbps.
Este en un informe en ingles que muestra el impacto que tiene las ondas 5G en la biología humana, se recomienda traducirlo para poder entenderlo en sub totalidad
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
This document reviews the OFDM-IDMA technique and its implementations. It begins with introductions to OFDM and OFDM-IDMA. OFDM-IDMA uses interleaving instead of spreading sequences to distinguish users, avoiding bandwidth expansion without coding gain. The document then summarizes various implementations of OFDM-IDMA using discrete wavelet transform, MIMO systems, and implementations on FPGA. It also discusses implementations using finite Radon transform and discrete wavelet transform. Finally, it proposes future work on implementing OFDM-IDMA using Radon transform and performing comparative analysis of wavelet, FFT, and Radon-based OFDM-IDMA systems over AWGN and Rayleigh fading channels.
Simulation of Few Mode Fiber Communication System Using Adaptive Recursive le...rahulmonikasharma
The document summarizes research on simulation of few mode fiber communication systems using adaptive algorithms. It discusses using the recursive least squares (RLS) algorithm to improve convergence speed but with increased complexity compared to frequency domain least mean square (FD-LMS) algorithms. The FD-LMS algorithm is used as a reference. A step size controller is also proposed to improve convergence behavior. Previous studies on adaptive frequency domain equalization schemes and use of normalized frequency domain adaptive filters to increase convergence speed over long transmission distances are also summarized.
1) The document analyzes the effect of intercarrier interference (ICI) on single carrier orthogonal frequency division multiplexing (SC-OFDM) systems.
2) It proposes a novel magnitude-keyed modulation scheme that provides SC-OFDM immunity to ICI. This outperforms other modulation schemes like OFDM, SC-OFDM, and MC-CDMA that use phase shift keying or quadrature amplitude modulation in environments with severe ICI.
3) The analysis shows that the effect of ICI on SC-OFDM signals is simply a phase offset on each data symbol, whereas ICI introduces interference between subcarriers for OFDM. Therefore, SC-OFDM has significantly better performance
Integrated DWDM and MIMO-OFDM System for 4G High Capacity Mobile Communicatio...CSCJournals
This document describes a simulation of an integrated 64-channel dense wavelength division multiplexing (DWDM) system with multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) technology for high-capacity 4G mobile communication. The DWDM transmitter is designed to transmit baseband non-return-to-zero signals over fiber at 10 Gbps per channel for a total of 640 Gbps. After transmission over fiber with dispersion compensation, the signals are input to the MIMO-OFDM system. Space-time block coding is used to provide diversity in the MIMO-OFDM system. The performance is analyzed in terms of bit error rate with signal-to-noise ratio, achieving a desirable B
1) The document describes a study on improving channel capacity for radio propagation in ocean vessels using MIMO-OFDM systems.
2) It proposes using 16-QAM modulation, Alamouti SFBC coding, and a Rayleigh fading channel model to increase channel capacity and signal reliability despite metal reflections.
3) Simulation results show MIMO techniques like spatial multiplexing and Alamouti coding improve channel capacity and lower bit error rates compared to SISO in engine room and coupled compartment environments.
Outage performance users located outside D2D coverage area in downlink cellul...journalBEEI
Device-to-device (D2D) communication has been proposed to employ the proximity between two devices to enhance the overall spectrum utilization of a crowded cellular network. With the help of geometric probability tools, this framework considers the performance of cellular users under spatial separation with the D2D pair is investigated. The measurement results and analytical expression of outage probability show that the proposed frameworks improve the outage performance at a high signal-tonoise ratio (SNR) at the base station. Results also interpret that the distances between nodes in the D2D-assisted network make slight impacts on the performance of the cellular user.
Peak to Average Power Ratio Reduction in Mc Cdma System by Using Pulse Shapin...IOSR Journals
Abstract: One of the drawback of multicarrier code division multiple access (MC CDMA) is the high peak to
average power ratio (PAPR). In this paper A novel scheme based on pulse shaping described for PAPR
reduction. Here three different pulse shaping filters (Raised cosine, Sinc power pulse and Nyqist pulse) are
described for PAPR reduction in MC CDMA system. The method is based on the proper selection of the pulses
for shaping the different sub carriers of the MC CDMA modulation scheme. It is shown by computer simulation
that the scheme achieves the significant improvement in PAPR reduction in MC CDMA system. Its
implementation complexity is much low in comparison to the previous published methods. Thus pulse shaping
technique can be used not only to shape the spectrum of the transmitted signal but also to reduce its PAPR. In
computer simulation It is observed that by using nyquist pulse near about 6.8 db PAPR is obtained. Which is
considerable PAPR reduction than a PAPR value of Original MC CDMA signal
Keywords: MC CDMA, PAPR, PULSE SHAPING, BPSK
Beamforming for Multiuser Massive MIMO Systems: Digital versus Hybrid Analog-...T. E. BOGALE
The document compares digital and hybrid analog-digital beamforming for multiuser massive MIMO systems. It describes the system model and problem formulation. Digital beamforming requires many RF chains and ADCs which is expensive for massive MIMO. Hybrid beamforming uses limited RF chains by employing analog beamforming at the transmitter with phase shifters. The document proposes a hybrid beamforming algorithm that minimizes the mean square error between the estimated signals of digital and hybrid beamforming. Simulation results show the proposed hybrid approach achieves similar performance as digital beamforming using fewer RF chains and phase shifters. It concludes hybrid beamforming provides significant savings in hardware complexity over digital beamforming for multiuser massive MIMO systems.
A NEW HYBRID DIVERSITY COMBINING SCHEME FOR MOBILE RADIO COMMUNICATION SYSTEM...ijcsit
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced
system complexity.
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced system complexity.
Comparatively analysis of FBG optical fiber in 25 & 35 Gbps DCDM based Commun...IJERD Editor
This document compares the performance of a 25 Gbps and 35 Gbps optical communication system using duty cycle division multiplexing (DCDM) with and without fiber Bragg grating (FBG) optical filtering. It describes the DCDM technique which allows multiple users to transmit simultaneously using different duty cycles. The document presents the system design using a 5 user DCDM system and evaluates the performance based on signal-to-noise ratio, Q-factor, and bit error rate. It is observed that using an FBG filter improves the system performance for both the 25 Gbps and 35 Gbps systems.
PERFORMANCE ANALYSIS OF QOS PARAMETERS LIKE PSNR, MAE & RMSE USED IN IMAGE TR...Journal For Research
Wireless designers constantly seek to improve the spectrum efficiency/capacity, coverage of wireless networks and link reliability. In this direction, Space-time wireless technology that uses multiple antennas along with appropriate signaling and receiver techniques that offers a powerful tool for improving the wireless performance is used in this thesis work. A special version of STBC called ‘Alamouti code’ is used. PSK modulation scheme is used for modulation of data. In this thesis work, the Space-Time Block Codes (STBC) is used in WLAN wireless network that uses multiple numbers of antennas at both transmitter and receiver. The STBC which includes the Alamouti Scheme for 2 transmit antenna and a different number of receiving antenna has been studied, simulated and analyzed. The simulation has been done in MATLAB. Throughput and several parameter performance has been analyzed using the MATLAB.A sample image is transmitted to compare the performance of various parameters like RMSE, PSNR, MAE etc. All the parameters are plotted against SNR (in dB) values ranging from -18 to 30. Various observations being made for the improvement in various parameters with increasing SNR and/or with changing diversity scheme. AWGN channel is used here for communication of sampled image data.
Performance Analysis of Massive MIMO Downlink System with Imperfect Channel S...IJRES Journal
We investigate the ergodic sum rate and required transmit power of a single-cell massive
multiple-input multiple-output (MIMO) downlink system. The system considered in this paper is based on two
linear beamforming schemes, that is, maximum ratio transmission (MRT) beamforming and zero-forcing (ZF)
beamforming. What’s more, we use minimum mean square error (MMSE) channel estimation to get imperfect
channel state information (CSI). Compared with the perfect CSI case, both theoretical analysis and simulation
results show that the system performance is different when the imperfect CSI is taken into account.
A new look on CSI imperfection in downlink NOMA systemsjournalBEEI
- The document analyzes the performance of downlink non-orthogonal multiple access (NOMA) systems under imperfect channel state information (CSI) and Nakagami-m fading.
- It derives closed-form expressions for the outage probability of two users in such NOMA systems considering the joint impact of imperfect CSI and Nakagami-m fading.
- Monte Carlo simulations are conducted to verify the accuracy of the analytical outage probability expressions derived for the two users under the system and channel models considered.
techInvestigations with mode division multiplexed transmissionelelijjournal
This article presents proposed topology for mode division multiplexed link with SPDML and VCSEL, modulate electrical signal of 820nm wavelength. Transmission performance has been investigated for numerous modes, bit rates (2.5 to 10Gbps), transmission lengths of MMF (1 to 100km) and attenuation factor in conjunction with parabolic operational mode. Results illustrated successful performance up to nine modes in mode-division multiplexed transmission. Performance is improved at low data rates, illustrated higher OSNR with lower BER,-5dB attenuation factor. Though, at higher bit rate and longer
transmission length received OSNR is unsteady. It further inferred that transmission with large number of multiplexed modes result in degraded performance, augmented with minimization of mode coupling losses.Mode division multiplexed multimode optical communication can be a viable option for supplementary capacity augment in the preexisting and future fiber optic communication links.
Ofdm mimo and v-blast algorithm-key to high speed wireless communicationIAEME Publication
This document provides an overview of OFDM-MIMO technology for high-speed wireless communication. It discusses how OFDM divides a high-rate data stream into parallel lower-rate substreams that are transmitted over multiple carriers. MIMO is then used to further improve data rates and quality of service by exploiting multiple antennas at the transmitter and receiver. The document also describes V-BLAST, an algorithm used in MIMO systems to separate simultaneously transmitted signals at the receiver through ordered cancellation.
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
This document analyzes the performance of M-QAM modulation in OFDM systems. It begins with an introduction to OFDM and how it addresses issues like intersymbol interference caused by multipath fading. It then describes M-QAM and M-PSK modulation schemes used in OFDM. Through MATLAB simulations, it evaluates the bit error rate performance of different modulation orders in AWGN and frequency selective Rayleigh fading channels. The results show that higher order QAM in OFDM provides better performance with lower bit error rates than PSK, especially at higher SNR values. Therefore, QAM is determined to be a better choice than PSK for high data rate transmission using OFDM.
This document examines using a Minimum-Mean-Square-Error (MMSE) adaptive algorithm reception technique for 6th derivative Ultra-wideband (UWB) Gaussian pulse shape signals compared to a conventional UWB Rake receiver. The MMSE adaptive algorithm is more efficient due to its ability to adapt to changes in the IEEE 802.15.3a UWB multipath channel model. Performance is evaluated for Direct-Sequence and Time-Hopping transmission schemes over the channel in the presence of narrowband interference and multiple access interference from other UWB users. Simulation results show the MMSE adaptive algorithm receiver has better performance than the UWB Rake receiver due to its adaptability.
Circularly polarized antenna array based on hybrid couplers for 5G devicesjournalBEEI
This paper depicts a wideband circularly polarized (CP) antenna for 5G devices. The antenna array has a 3D structure including four simple printed dipole elements with directional radiations, high gain, and high efficiency. It achieves a CP by using the sequential rotation (SR) feeding based on 90°-3dB hybrid couplers in the proposed feeding network. The antenna array bandwidth is wide, 26.7%, with an operating frequency band from 3.35 GHz to 4.35 GHz. The antenna achieves a high peak gain of 10.73 dBi and high efficiency of 93.75%. Besides, the antenna gain is stable over the operating bandwidth (BW). At the centre operating frequency of 3.75 GHz, the angle of circular polarization is 51°. The antenna is designed and fabricated on the Rogers 4003 C substrate. The measured S11 is well matching with the simulation results. With the above characteristics, the proposed antenna can be a suitable candidate for 5G devices.
Performance Evaluation of PAPR Reduction with SER and BER by Modified Clippin...ijcsse
This paper work focuses on performance analysis of PAPR reduction of orthogonal frequency division multiplexing (OFDM) using amplitude clipping & filtering based design. Now a days one of the most proficient multi-carrier transmission techniques widely used today is orthogonal frequency division multiplexing (OFDM) which has been implemented by the next generation wireless communication technology: Long Term Evolution (LTE). Extra robustness to multipath fading and impulse noise is provided OFDM. It eliminates inter symbol interference (ISI) & inter carrier interference (ICI) with certain procedure. Therefore peak to average power ratio (PAPR) is the basic problem with OFDM. However in this paper we proposed a reduction procedure of the PAPR by using clipping and filtering. Here we use a composed high pass , low pass & Chevyshev band pass filter II after amplitude clipping to reduce the PAPR. The performance of the system in terms of bit error rate (BER) and symbol error rate (SER) is also investigated as a new filter based clipping method is proposed. Our proposed clipping method with and composed high pass the Chevyshev bandpass filter II in PAPR performance of the system with a little compromise of BER & SER showing the significant improvement in Quadrature Amplitude Modulation (QAM).
A Potent MIMO–OFDM System Designed for Optimum BER and its Performance Anal...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
In this work, high-speed transmission over the long-haul optical channel using orthogonal frequency division multiplexing (OFDM) was investigated. Furthermore, we recommend mixing polarization division multiplexing (PDM) with coherent OFDM (CO-OFDM) and quadrature amplitude modulation (16-QAM) to improve spectral efficiency (SE) while transmitting over a wavelength division multiplexing (WDM) system.
An 800 Gb/s WDM PDM-CO-OFDM-16QAM transmission system with various channel spacing of 100 GHz, 50 GHz, and 25 GHz is examined utilizing the OptiSystem (2021) version 18.0 software package over ten spans of 60 km standard single-mode fiber (SSMF). Different channel spacing WDM systems have been compared in terms of performance and SE. The results reveal that the WDM system with 100 GHz channel spacing has a longer transmission range and needs minimal optical signal to noise ratio (OSNR) at the reception. The 25 GHz channel spacing WDM system exceeds the others in terms of SE. Further, the effect of ultra-low loss and large effective area fiber in lowering span loss and nonlinear effects for
25 GHz channel spacing WDM system is investigated. The findings show that the system performance with the new fiber outperforms the SSMF.
The acceptable bit error rate (BER) for this study is 0.033 (20% concatenated forward error correction (FEC) threshold).
Performance analysis of adaptive filter channel estimated MIMO OFDM communica...IJECEIAES
Advanced Communication Systems are wideband systems to support multiple applications such as audio, video and data so and so forth. These systems require high spectral efficiency and data rates. In addition, they should provide multipath fading and inter-symbol interference (ISI) free transmission. Multiple input multiple output orthogonal frequency division multiplexing (MIMO OFDM) meets these requirements Hence, MIMOOFDM is the most preferable technique for long term evaluation advanced (LTEA). The primary objective of this paper is to control bit error rate (BER) by proper channel coding, pilot carriers, adaptive filter channel estimation schemes and space time coding (STC). A combination of any of these schemes results in better BER performance over individual schemes. System performance is analyzed for various digital modulation schemes. In this paper, adaptive filter channel estimated MIMO OFDM system is proposed by integrating channel coding, adaptive filter channel estimation, digital modulation and space time coding. From the simulation results, channel estimated 2×2 MIMO OFDM system shows superior performance over individual schemes.
Transmitting audio via fiber optics under nonlinear effects and optimized tun...IJECEIAES
The ability of fiber optic to overcome the signal transmission problems is making it a dominant transmission medium. Despite of this major positive attribute of optic fibers, there is still a downside for using the fiber optic communication; that is the nonlinearity problem. For the first time, a design of an audio signal is suggested and executed in MATLAB with integration with OptiSystem TM Software .The audio signal then transmitted in different shapes of modulation signals (NRZ, RZ, & RC) for different distances (100 km & 75 km) via a fiber optic media to be received in a receiving part of the simulated system. Three tests are used to do so. The first is the Quality-facto (Q-Factor) against the received power, second test is eye diagram performance and finally is the measuring of the amplitude of output (received) signal for each modulation signal shape using the Oscilloscope Visualizer. The NZR modulation signal was found to be the best one of the three used signals’ types in all three tests. The Q-factor for NRZ pulse shape (=12) was higher than that for RZ (=10) and RC (=8) for a 100 km distance at the same received power level.
Digital signal processing techniques for lti fiber impairment compensationeSAT Journals
Abstract Coherent detection is one of the active research areas for the development of high speed, high spectral efficient optical communication network. Digital signal processing is the important technique for compensating the fiber transmission impairments because of number of advantages such as signal can be amplified, delayed, splitted and manipulated without degrading the signal quality. This paper presents DSP compensation algorithms for linear time invariant (LTI) impairment such as chromatic dispersion (CD) and polarization mode dispersion (PMD) in optical fiber communication. We presented a mathematical framework for compensation of LTI fiber impairments. This paper also focuses the different compensation methods both in time and frequency domain for chromatic dispersion compensation. These DSP techniques confirm that coherent detection with high data rates will become feasible in future for compensating transmission impairments. Keywords: Coherent Detection, Chromatic Dispersion, Polarization Mode Dispersion
Modelling and QoS-Achieving Solution in full-duplex Cellular SystemsIJCNCJournal
The global bandwidth scarcity and the ever-growing demand for fast wireless services have motivated the quest for new techniques that enhance the spectral efficiency (SE) of wireless systems. Most conventional SE increasing methods (e.g., adaptive modulation and coding) have already been exhausted. Single-channel full-duplex (SCFD) communication is a new attractive approach in which each node may simultaneously receive and transmit over the same frequency channel, and thus, it has the potential to double the current SE figures. In this paper, we derive a model for the signal-to-interference-plus-noise ratio (SINR) in a SCFD-based cellular system with imperfect self-interference cancellation. Furthermore, given a set of uplink and downlink quality of service requirements, we answer the following two fundamental questions. First, is this set achievable in the SCFD-based cellular system? Second, if the given set is achievable, what is the optimal achieving policy? To that end, we provide a unified model for the SCFD-based cellular system, and give insights in the matrix of interference channel gains. Simulation results suggest that depending on the locations of the users, a combination of full-duplex and half-duplex modes over the whole network is more favourable policy
Outage performance users located outside D2D coverage area in downlink cellul...journalBEEI
Device-to-device (D2D) communication has been proposed to employ the proximity between two devices to enhance the overall spectrum utilization of a crowded cellular network. With the help of geometric probability tools, this framework considers the performance of cellular users under spatial separation with the D2D pair is investigated. The measurement results and analytical expression of outage probability show that the proposed frameworks improve the outage performance at a high signal-tonoise ratio (SNR) at the base station. Results also interpret that the distances between nodes in the D2D-assisted network make slight impacts on the performance of the cellular user.
Peak to Average Power Ratio Reduction in Mc Cdma System by Using Pulse Shapin...IOSR Journals
Abstract: One of the drawback of multicarrier code division multiple access (MC CDMA) is the high peak to
average power ratio (PAPR). In this paper A novel scheme based on pulse shaping described for PAPR
reduction. Here three different pulse shaping filters (Raised cosine, Sinc power pulse and Nyqist pulse) are
described for PAPR reduction in MC CDMA system. The method is based on the proper selection of the pulses
for shaping the different sub carriers of the MC CDMA modulation scheme. It is shown by computer simulation
that the scheme achieves the significant improvement in PAPR reduction in MC CDMA system. Its
implementation complexity is much low in comparison to the previous published methods. Thus pulse shaping
technique can be used not only to shape the spectrum of the transmitted signal but also to reduce its PAPR. In
computer simulation It is observed that by using nyquist pulse near about 6.8 db PAPR is obtained. Which is
considerable PAPR reduction than a PAPR value of Original MC CDMA signal
Keywords: MC CDMA, PAPR, PULSE SHAPING, BPSK
Beamforming for Multiuser Massive MIMO Systems: Digital versus Hybrid Analog-...T. E. BOGALE
The document compares digital and hybrid analog-digital beamforming for multiuser massive MIMO systems. It describes the system model and problem formulation. Digital beamforming requires many RF chains and ADCs which is expensive for massive MIMO. Hybrid beamforming uses limited RF chains by employing analog beamforming at the transmitter with phase shifters. The document proposes a hybrid beamforming algorithm that minimizes the mean square error between the estimated signals of digital and hybrid beamforming. Simulation results show the proposed hybrid approach achieves similar performance as digital beamforming using fewer RF chains and phase shifters. It concludes hybrid beamforming provides significant savings in hardware complexity over digital beamforming for multiuser massive MIMO systems.
A NEW HYBRID DIVERSITY COMBINING SCHEME FOR MOBILE RADIO COMMUNICATION SYSTEM...ijcsit
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced
system complexity.
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced system complexity.
Comparatively analysis of FBG optical fiber in 25 & 35 Gbps DCDM based Commun...IJERD Editor
This document compares the performance of a 25 Gbps and 35 Gbps optical communication system using duty cycle division multiplexing (DCDM) with and without fiber Bragg grating (FBG) optical filtering. It describes the DCDM technique which allows multiple users to transmit simultaneously using different duty cycles. The document presents the system design using a 5 user DCDM system and evaluates the performance based on signal-to-noise ratio, Q-factor, and bit error rate. It is observed that using an FBG filter improves the system performance for both the 25 Gbps and 35 Gbps systems.
PERFORMANCE ANALYSIS OF QOS PARAMETERS LIKE PSNR, MAE & RMSE USED IN IMAGE TR...Journal For Research
Wireless designers constantly seek to improve the spectrum efficiency/capacity, coverage of wireless networks and link reliability. In this direction, Space-time wireless technology that uses multiple antennas along with appropriate signaling and receiver techniques that offers a powerful tool for improving the wireless performance is used in this thesis work. A special version of STBC called ‘Alamouti code’ is used. PSK modulation scheme is used for modulation of data. In this thesis work, the Space-Time Block Codes (STBC) is used in WLAN wireless network that uses multiple numbers of antennas at both transmitter and receiver. The STBC which includes the Alamouti Scheme for 2 transmit antenna and a different number of receiving antenna has been studied, simulated and analyzed. The simulation has been done in MATLAB. Throughput and several parameter performance has been analyzed using the MATLAB.A sample image is transmitted to compare the performance of various parameters like RMSE, PSNR, MAE etc. All the parameters are plotted against SNR (in dB) values ranging from -18 to 30. Various observations being made for the improvement in various parameters with increasing SNR and/or with changing diversity scheme. AWGN channel is used here for communication of sampled image data.
Performance Analysis of Massive MIMO Downlink System with Imperfect Channel S...IJRES Journal
We investigate the ergodic sum rate and required transmit power of a single-cell massive
multiple-input multiple-output (MIMO) downlink system. The system considered in this paper is based on two
linear beamforming schemes, that is, maximum ratio transmission (MRT) beamforming and zero-forcing (ZF)
beamforming. What’s more, we use minimum mean square error (MMSE) channel estimation to get imperfect
channel state information (CSI). Compared with the perfect CSI case, both theoretical analysis and simulation
results show that the system performance is different when the imperfect CSI is taken into account.
A new look on CSI imperfection in downlink NOMA systemsjournalBEEI
- The document analyzes the performance of downlink non-orthogonal multiple access (NOMA) systems under imperfect channel state information (CSI) and Nakagami-m fading.
- It derives closed-form expressions for the outage probability of two users in such NOMA systems considering the joint impact of imperfect CSI and Nakagami-m fading.
- Monte Carlo simulations are conducted to verify the accuracy of the analytical outage probability expressions derived for the two users under the system and channel models considered.
techInvestigations with mode division multiplexed transmissionelelijjournal
This article presents proposed topology for mode division multiplexed link with SPDML and VCSEL, modulate electrical signal of 820nm wavelength. Transmission performance has been investigated for numerous modes, bit rates (2.5 to 10Gbps), transmission lengths of MMF (1 to 100km) and attenuation factor in conjunction with parabolic operational mode. Results illustrated successful performance up to nine modes in mode-division multiplexed transmission. Performance is improved at low data rates, illustrated higher OSNR with lower BER,-5dB attenuation factor. Though, at higher bit rate and longer
transmission length received OSNR is unsteady. It further inferred that transmission with large number of multiplexed modes result in degraded performance, augmented with minimization of mode coupling losses.Mode division multiplexed multimode optical communication can be a viable option for supplementary capacity augment in the preexisting and future fiber optic communication links.
Ofdm mimo and v-blast algorithm-key to high speed wireless communicationIAEME Publication
This document provides an overview of OFDM-MIMO technology for high-speed wireless communication. It discusses how OFDM divides a high-rate data stream into parallel lower-rate substreams that are transmitted over multiple carriers. MIMO is then used to further improve data rates and quality of service by exploiting multiple antennas at the transmitter and receiver. The document also describes V-BLAST, an algorithm used in MIMO systems to separate simultaneously transmitted signals at the receiver through ordered cancellation.
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
This document analyzes the performance of M-QAM modulation in OFDM systems. It begins with an introduction to OFDM and how it addresses issues like intersymbol interference caused by multipath fading. It then describes M-QAM and M-PSK modulation schemes used in OFDM. Through MATLAB simulations, it evaluates the bit error rate performance of different modulation orders in AWGN and frequency selective Rayleigh fading channels. The results show that higher order QAM in OFDM provides better performance with lower bit error rates than PSK, especially at higher SNR values. Therefore, QAM is determined to be a better choice than PSK for high data rate transmission using OFDM.
This document examines using a Minimum-Mean-Square-Error (MMSE) adaptive algorithm reception technique for 6th derivative Ultra-wideband (UWB) Gaussian pulse shape signals compared to a conventional UWB Rake receiver. The MMSE adaptive algorithm is more efficient due to its ability to adapt to changes in the IEEE 802.15.3a UWB multipath channel model. Performance is evaluated for Direct-Sequence and Time-Hopping transmission schemes over the channel in the presence of narrowband interference and multiple access interference from other UWB users. Simulation results show the MMSE adaptive algorithm receiver has better performance than the UWB Rake receiver due to its adaptability.
Circularly polarized antenna array based on hybrid couplers for 5G devicesjournalBEEI
This paper depicts a wideband circularly polarized (CP) antenna for 5G devices. The antenna array has a 3D structure including four simple printed dipole elements with directional radiations, high gain, and high efficiency. It achieves a CP by using the sequential rotation (SR) feeding based on 90°-3dB hybrid couplers in the proposed feeding network. The antenna array bandwidth is wide, 26.7%, with an operating frequency band from 3.35 GHz to 4.35 GHz. The antenna achieves a high peak gain of 10.73 dBi and high efficiency of 93.75%. Besides, the antenna gain is stable over the operating bandwidth (BW). At the centre operating frequency of 3.75 GHz, the angle of circular polarization is 51°. The antenna is designed and fabricated on the Rogers 4003 C substrate. The measured S11 is well matching with the simulation results. With the above characteristics, the proposed antenna can be a suitable candidate for 5G devices.
Performance Evaluation of PAPR Reduction with SER and BER by Modified Clippin...ijcsse
This paper work focuses on performance analysis of PAPR reduction of orthogonal frequency division multiplexing (OFDM) using amplitude clipping & filtering based design. Now a days one of the most proficient multi-carrier transmission techniques widely used today is orthogonal frequency division multiplexing (OFDM) which has been implemented by the next generation wireless communication technology: Long Term Evolution (LTE). Extra robustness to multipath fading and impulse noise is provided OFDM. It eliminates inter symbol interference (ISI) & inter carrier interference (ICI) with certain procedure. Therefore peak to average power ratio (PAPR) is the basic problem with OFDM. However in this paper we proposed a reduction procedure of the PAPR by using clipping and filtering. Here we use a composed high pass , low pass & Chevyshev band pass filter II after amplitude clipping to reduce the PAPR. The performance of the system in terms of bit error rate (BER) and symbol error rate (SER) is also investigated as a new filter based clipping method is proposed. Our proposed clipping method with and composed high pass the Chevyshev bandpass filter II in PAPR performance of the system with a little compromise of BER & SER showing the significant improvement in Quadrature Amplitude Modulation (QAM).
A Potent MIMO–OFDM System Designed for Optimum BER and its Performance Anal...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
In this work, high-speed transmission over the long-haul optical channel using orthogonal frequency division multiplexing (OFDM) was investigated. Furthermore, we recommend mixing polarization division multiplexing (PDM) with coherent OFDM (CO-OFDM) and quadrature amplitude modulation (16-QAM) to improve spectral efficiency (SE) while transmitting over a wavelength division multiplexing (WDM) system.
An 800 Gb/s WDM PDM-CO-OFDM-16QAM transmission system with various channel spacing of 100 GHz, 50 GHz, and 25 GHz is examined utilizing the OptiSystem (2021) version 18.0 software package over ten spans of 60 km standard single-mode fiber (SSMF). Different channel spacing WDM systems have been compared in terms of performance and SE. The results reveal that the WDM system with 100 GHz channel spacing has a longer transmission range and needs minimal optical signal to noise ratio (OSNR) at the reception. The 25 GHz channel spacing WDM system exceeds the others in terms of SE. Further, the effect of ultra-low loss and large effective area fiber in lowering span loss and nonlinear effects for
25 GHz channel spacing WDM system is investigated. The findings show that the system performance with the new fiber outperforms the SSMF.
The acceptable bit error rate (BER) for this study is 0.033 (20% concatenated forward error correction (FEC) threshold).
Performance analysis of adaptive filter channel estimated MIMO OFDM communica...IJECEIAES
Advanced Communication Systems are wideband systems to support multiple applications such as audio, video and data so and so forth. These systems require high spectral efficiency and data rates. In addition, they should provide multipath fading and inter-symbol interference (ISI) free transmission. Multiple input multiple output orthogonal frequency division multiplexing (MIMO OFDM) meets these requirements Hence, MIMOOFDM is the most preferable technique for long term evaluation advanced (LTEA). The primary objective of this paper is to control bit error rate (BER) by proper channel coding, pilot carriers, adaptive filter channel estimation schemes and space time coding (STC). A combination of any of these schemes results in better BER performance over individual schemes. System performance is analyzed for various digital modulation schemes. In this paper, adaptive filter channel estimated MIMO OFDM system is proposed by integrating channel coding, adaptive filter channel estimation, digital modulation and space time coding. From the simulation results, channel estimated 2×2 MIMO OFDM system shows superior performance over individual schemes.
Transmitting audio via fiber optics under nonlinear effects and optimized tun...IJECEIAES
The ability of fiber optic to overcome the signal transmission problems is making it a dominant transmission medium. Despite of this major positive attribute of optic fibers, there is still a downside for using the fiber optic communication; that is the nonlinearity problem. For the first time, a design of an audio signal is suggested and executed in MATLAB with integration with OptiSystem TM Software .The audio signal then transmitted in different shapes of modulation signals (NRZ, RZ, & RC) for different distances (100 km & 75 km) via a fiber optic media to be received in a receiving part of the simulated system. Three tests are used to do so. The first is the Quality-facto (Q-Factor) against the received power, second test is eye diagram performance and finally is the measuring of the amplitude of output (received) signal for each modulation signal shape using the Oscilloscope Visualizer. The NZR modulation signal was found to be the best one of the three used signals’ types in all three tests. The Q-factor for NRZ pulse shape (=12) was higher than that for RZ (=10) and RC (=8) for a 100 km distance at the same received power level.
Digital signal processing techniques for lti fiber impairment compensationeSAT Journals
Abstract Coherent detection is one of the active research areas for the development of high speed, high spectral efficient optical communication network. Digital signal processing is the important technique for compensating the fiber transmission impairments because of number of advantages such as signal can be amplified, delayed, splitted and manipulated without degrading the signal quality. This paper presents DSP compensation algorithms for linear time invariant (LTI) impairment such as chromatic dispersion (CD) and polarization mode dispersion (PMD) in optical fiber communication. We presented a mathematical framework for compensation of LTI fiber impairments. This paper also focuses the different compensation methods both in time and frequency domain for chromatic dispersion compensation. These DSP techniques confirm that coherent detection with high data rates will become feasible in future for compensating transmission impairments. Keywords: Coherent Detection, Chromatic Dispersion, Polarization Mode Dispersion
Modelling and QoS-Achieving Solution in full-duplex Cellular SystemsIJCNCJournal
The global bandwidth scarcity and the ever-growing demand for fast wireless services have motivated the quest for new techniques that enhance the spectral efficiency (SE) of wireless systems. Most conventional SE increasing methods (e.g., adaptive modulation and coding) have already been exhausted. Single-channel full-duplex (SCFD) communication is a new attractive approach in which each node may simultaneously receive and transmit over the same frequency channel, and thus, it has the potential to double the current SE figures. In this paper, we derive a model for the signal-to-interference-plus-noise ratio (SINR) in a SCFD-based cellular system with imperfect self-interference cancellation. Furthermore, given a set of uplink and downlink quality of service requirements, we answer the following two fundamental questions. First, is this set achievable in the SCFD-based cellular system? Second, if the given set is achievable, what is the optimal achieving policy? To that end, we provide a unified model for the SCFD-based cellular system, and give insights in the matrix of interference channel gains. Simulation results suggest that depending on the locations of the users, a combination of full-duplex and half-duplex modes over the whole network is more favourable policy
This document describes a simulation of transmitting 20 channels of either 10 Gbps or 20 Gbps data over 80 km spans of conventional single mode fiber using wavelength division multiplexing in the L-band spectrum region. Both pre-compensation and post-compensation techniques for dispersion were considered. Post-compensation provided better performance with transmission distances of up to 720 km for a total throughput of 200 Gbps and 320 km for 400 Gbps, and lower bit error rates compared to pre-compensation. Non-linear effects and amplified spontaneous emission noise were also accounted for in the simulation.
The document discusses Coherent Optical OFDM (CO-OFDM) and analyzes its performance at different data rates such as 1Gbps, 20Gbps, and 100Gbps. 4QAM-OFDM signals are generated and transmitted through 250km of fiber. The results show that distortions in the OFDM spectrum and QAM constellations increase as the data rate increases, due to nonlinearities in the fiber. CO-OFDM has advantages over other modulation formats as it provides both coherent detection and OFDM modulation, but its performance is affected by fiber nonlinearities at high data rates due to its high peak-to-average power ratio.
Performance evaluation of 4-quadrature amplitude modulation over orthogonal ...IJECEIAES
Orthogonal frequency division multiplexing (OFDM) is a multicarrier modulation (MCM) technique that divides the wide bandwidth into parallel narrow bands, each of which is modulated by orthogonal subcarriers. Currently, OFDM is a high-spectral efficiency modulation technique that is used in a variety of wired and wireless applications. The transmitted signal in a wireless communication channel spreads from transmitter to receiver through multiple reflective paths. This triggers multipath fading, which causes variations in the received signal's amplitude and phase. Slow/fast and frequency-selective/frequency-nonselective are the main types of multipath fading channels. Therefore, in this paper, we proposed new models for modeling multipath fading channels, such as the exponential fading channel and the Gamma fading channel. In addition, new bit-error-rate (BER) derivations have been derived. The performance of the OFDM system over proposed channel models has been evaluated using Monte-Carlo simulation and compared to the Rayleigh fading channel model. The obtained results via simulations show that the exponential fading channel at a rate parameter (λ=0.5) outperforms the Rayleigh fading channel by 6 dB for all values of Eb/No, while the Gamma fading channel at (α=2) outperforms the Rayleigh fading channel by 3 dB for all values of Eb/No.
Intersymbol interference distortion cancellation using a modified maximal rat...Alexander Decker
The document describes a modified maximum ratio combiner (MRC) receiver for correcting intersymbol interference (ISI) distortion in mobile wireless channels. The modified MRC uses a single radio frequency (RF) chain and matched filter, whereas a conventional MRC uses multiple RF chains and matched filters depending on the number of propagation paths. The two received signal paths are combined using MRC at the RF stage before being processed through the single RF chain and matched filter. Simulation results showed the modified MRC provides approximately the same bit error rate performance as the conventional MRC, but with relatively lower complexity and processing time since it requires fewer hardware components. Therefore, the modified MRC is a lower cost alternative for mitigating ISI distortion in
Comparative ber analysis of mitigation of ici through sc,ml and ekf methods i...IAEME Publication
This document summarizes a research paper that was published in the International Journal of Electronics and Communication Engineering & Technology. The paper investigates methods to mitigate inter-carrier interference (ICI) in OFDM systems, which is caused by frequency offsets. It compares the performance of three ICI mitigation techniques: self-cancellation, maximum likelihood estimation, and an extended Kalman filter method. Through simulations, the paper shows that these three techniques are effective at reducing the effects of ICI. For high frequency offsets and higher order modulation schemes, the maximum likelihood and extended Kalman filter methods perform better than self-cancellation.
Performance of Wideband Mobile Channel with Perfect Synchronism BPSK vs QPSK ...Editor Jacotech
Direct-sequence code-division multiple access (DS-CDMA) is
currently the subject of much research as it is a promising
multiple access capability for third and fourth generations
mobile communication systems. The synchronous DS-CDMA
system is well known for eliminating the effects of multiple
access interference (MAI) which limits the capacity and
degrades the BER performance of the system. In this paper,
we investigate the bit error rate (BER) performance of a
synchronous DS-CDMA system over a wideband mobile
radio channel. The BER performance is affected by the
difference in path length ΔL and the number of arriving
signals N. Furthermore, the effect of these parameters is
examined on the synchronous DS-CDMA system for different
users’ number as well as different processing gain Gp. In this
environment and under the above conditions the performances
of the BPSK (Binary Phase Shift Keying) and the QPSK
(Quadrature Phase Shift Keying) modulations are compared.
The promising simulation results showed the possibility of
applying this system to the wideband mobile radio channel.
The document describes a novel multi-segment cylindrical dielectric resonator antenna (DRA) for broadband operation. The proposed antenna structure consists of three stacked cylindrical dielectric segments made of different materials and fed by a microstrip line. Simulation results show the antenna achieves a bandwidth of 2GHz from 6.5-8.5GHz, with a resonant frequency of 7.408GHz and reflection coefficient of -66.01dB. The multi-segment cylindrical DRA design offers potential for wireless applications requiring broadband performance such as WLAN and WiMAX systems.
Performance enhancement of maximum ratio transmission in 5G system with multi...IJECEIAES
This document summarizes a research paper that proposes improving the performance of 5G systems using maximum ratio transmission (MRT) with multi-user multiple-input multiple-output (MU-MIMO) by incorporating weighted overlap-add (WOLA) precoding. It compares the proposed WOLA-MRT system to a standard MRT system with orthogonal frequency-division multiplexing (OFDM). Simulation results show the proposed system achieves approximately 60% higher throughput and a 2% lower bit error rate than the standard system, demonstrating significant performance enhancements for 5G massive MIMO networks.
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.
Empirical analysis of polarization division multiplexing-dense wavelength di...IJECEIAES
This paper exemplifies dense wavelength division multiplexing combined with polarization division multiplexing with C-band frequency range-based single-mode fiber. In the proposed link, 32 independent channels with 16 individual wavelengths are multiplexed with two different angles of polarization. Each carrying 130 Gbps dual-polarization data with 200 GHz channel spacing claiming a net transmission rate of 4.16 Tbits/s with spectral efficiency of 69% with 20% side-mode-suppression-ratio (SMSR) and optical signal to noise ratio (OSNR) 40.7. The performance of the proposed techniques has been analyzed using optimized system parameters securing a minimum bit error rate (BER) 10-9 at a transmission distance up to 50 km.
CHANNEL ESTIMATION AND MULTIUSER DETECTION IN ASYNCHRONOUS SATELLITE COMMUNIC...ijwmn
In this paper, we propose a new method of channel estimation for asynchronous additive white Gaussian noise channels in satellite communications. This method is based on signals correlation and multiuser interference cancellation which adopts a successive structure. Propagation delays and signals amplitudes are jointly estimated in order to be used for data detection at the receiver. As, a multiuser detector, a single stage successive interference cancellation (SIC) architecture is analyzed and integrated to the channel estimation technique and the whole system is evaluated. The satellite access method adopted is the direct sequence code division multiple access (DS CDMA) one. To evaluate the channel estimation and the detection technique, we have simulated a satellite uplink with an asynchronous multiuser access.
Third Generation Wireless Modeling in Urban EnvironmentEECJOURNAL
The global mobile communication is fast growing in industry. This paper recommends appropriate settings to evaluate the performance of wireless mobile system deploying third generation networks in an urban environment. To meet this aim, a case Study of Sulaimanyia city is considered for this study by establishing suitable radio channel models. The work presents a statistical channel model, where fixed and nomadic analysis services are considered in the simulated radio coverage scenario. The cartographic dataset had been collected, and Matlab Software was used for showing the analysis and simulation results. Statistical channel models are derived that combine standard parameters such as separation distance, operating frequency and terminal height with more advanced and innovative parameters such as distance dependent shadowing and LOS probability.
Study of Polarization Mode Dispersion in the Optical Digital Connection to Hi...ijcnac
Polarization Mode Dispersion (PMD) is a factor which limits the bit rate of the optical transmissions. The PMD is such an effect which is time broadening due to the dependence of the group velocity to the signal polarization. The deformation effects of the impulses become considerable from 40 Gb/s. This paper, we reviews the degrade PMD effect in the telecommunications optical connections to high bit rate, due to the evolution of quality factor (Q) according to the fiber length, bit rate and PMD coefficient , well as the impact PMD on the degree of polarization and electrical power, we discuss also the representation of the polarization state and PMD vector on the Poincare sphere.
PERFORMANCE EVALUATION OF MC-CDMA SYSTEM OVER RAYLEIGH FADING CHANNELIJCSES Journal
Multi Carrier Code Division Multiple Access (MC-CDMA) is a well known technique for high speed
wireless data transmission .Two advanced technology was included in the MC-CDMA structure, such as
orthogonal frequency division multiplex (OFDM) and the code division multiple access (CDMA),so that it
benefits from the robustness of OFDM against multipath environment and from the capability of multiuser
multiplexing services that is achieved via (CDMA) system. MC-CDMA is a multicarrier spread spectrum
system which is classified as the candidate scheme for future mobile radio systems. In this paper MCCDMA
system, with Rayleigh fading channel and 16QAM array modulation, was simulated to investigate
the effects of different parameters on the system performance, such as processing gain; number of paths;
number of users; interleaving; and coding ratio.MC-CDMA performances can be considerably improved
by proper selection of these parameters. As expected, results show that MC-CDMA has a better performance over CDMA system.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Similar to CHARACTERIZATION OF PHYSICAL LAYER IMPAIRMENTS IMPACT ON OPTICAL FIBER TRANSMISSION SYSTEMS (20)
Submission Deadline: 30th September 2022
Acceptance Notification: Within Three Days’ time period
Online Publication: Within 24 Hrs. time Period
Expected Date of Dispatch of Printed Journal: 5th October 2022
MODELING AND ANALYSIS OF SURFACE ROUGHNESS AND WHITE LATER THICKNESS IN WIRE-...IAEME Publication
White layer thickness (WLT) formed and surface roughness in wire electric discharge turning (WEDT) of tungsten carbide composite has been made to model through response surface methodology (RSM). A Taguchi’s standard Design of experiments involving five input variables with three levels has been employed to establish a mathematical model between input parameters and responses. Percentage of cobalt content, spindle speed, Pulse on-time, wire feed and pulse off-time were changed during the experimental tests based on the Taguchi’s orthogonal array L27 (3^13). Analysis of variance (ANOVA) revealed that the mathematical models obtained can adequately describe performance within the parameters of the factors considered. There was a good agreement between the experimental and predicted values in this study.
A STUDY ON THE REASONS FOR TRANSGENDER TO BECOME ENTREPRENEURSIAEME Publication
The study explores the reasons for a transgender to become entrepreneurs. In this study transgender entrepreneur was taken as independent variable and reasons to become as dependent variable. Data were collected through a structured questionnaire containing a five point Likert Scale. The study examined the data of 30 transgender entrepreneurs in Salem Municipal Corporation of Tamil Nadu State, India. Simple Random sampling technique was used. Garrett Ranking Technique (Percentile Position, Mean Scores) was used as the analysis for the present study to identify the top 13 stimulus factors for establishment of trans entrepreneurial venture. Economic advancement of a nation is governed upon the upshot of a resolute entrepreneurial doings. The conception of entrepreneurship has stretched and materialized to the socially deflated uncharted sections of transgender community. Presently transgenders have smashed their stereotypes and are making recent headlines of achievements in various fields of our Indian society. The trans-community is gradually being observed in a new light and has been trying to achieve prospective growth in entrepreneurship. The findings of the research revealed that the optimistic changes are taking place to change affirmative societal outlook of the transgender for entrepreneurial ventureship. It also laid emphasis on other transgenders to renovate their traditional living. The paper also highlights that legislators, supervisory body should endorse an impartial canons and reforms in Tamil Nadu Transgender Welfare Board Association.
BROAD UNEXPOSED SKILLS OF TRANSGENDER ENTREPRENEURSIAEME Publication
Since ages gender difference is always a debatable theme whether caused by nature, evolution or environment. The birth of a transgender is dreadful not only for the child but also for their parents. The pain of living in the wrong physique and treated as second class victimized citizen is outrageous and fully harboured with vicious baseless negative scruples. For so long, social exclusion had perpetuated inequality and deprivation experiencing ingrained malign stigma and besieged victims of crime or violence across their life spans. They are pushed into the murky way of life with a source of eternal disgust, bereft sexual potency and perennial fear. Although they are highly visible but very little is known about them. The common public needs to comprehend the ravaged arrogance on these insensitive souls and assist in integrating them into the mainstream by offering equal opportunity, treat with humanity and respect their dignity. Entrepreneurship in the current age is endorsing the gender fairness movement. Unstable careers and economic inadequacy had inclined one of the gender variant people called Transgender to become entrepreneurs. These tiny budding entrepreneurs resulted in economic transition by means of employment, free from the clutches of stereotype jobs, raised standard of living and handful of financial empowerment. Besides all these inhibitions, they were able to witness a platform for skill set development that ignited them to enter into entrepreneurial domain. This paper epitomizes skill sets involved in trans-entrepreneurs of Thoothukudi Municipal Corporation of Tamil Nadu State and is a groundbreaking determination to sightsee various skills incorporated and the impact on entrepreneurship.
DETERMINANTS AFFECTING THE USER'S INTENTION TO USE MOBILE BANKING APPLICATIONSIAEME Publication
The banking and financial services industries are experiencing increased technology penetration. Among them, the banking industry has made technological advancements to better serve the general populace. The economy focused on transforming the banking sector's system into a cashless, paperless, and faceless one. The researcher wants to evaluate the user's intention for utilising a mobile banking application. The study also examines the variables affecting the user's behaviour intention when selecting specific applications for financial transactions. The researcher employed a well-structured questionnaire and a descriptive study methodology to gather the respondents' primary data utilising the snowball sampling technique. The study includes variables like performance expectations, effort expectations, social impact, enabling circumstances, and perceived risk. Each of the aforementioned variables has a major impact on how users utilise mobile banking applications. The outcome will assist the service provider in comprehending the user's history with mobile banking applications.
ANALYSE THE USER PREDILECTION ON GPAY AND PHONEPE FOR DIGITAL TRANSACTIONSIAEME Publication
Technology upgradation in banking sector took the economy to view that payment mode towards online transactions using mobile applications. This system enabled connectivity between banks, Merchant and user in a convenient mode. there are various applications used for online transactions such as Google pay, Paytm, freecharge, mobikiwi, oxygen, phonepe and so on and it also includes mobile banking applications. The study aimed at evaluating the predilection of the user in adopting digital transaction. The study is descriptive in nature. The researcher used random sample techniques to collect the data. The findings reveal that mobile applications differ with the quality of service rendered by Gpay and Phonepe. The researcher suggest the Phonepe application should focus on implementing the application should be user friendly interface and Gpay on motivating the users to feel the importance of request for money and modes of payments in the application.
VOICE BASED ATM FOR VISUALLY IMPAIRED USING ARDUINOIAEME Publication
The prototype of a voice-based ATM for visually impaired using Arduino is to help people who are blind. This uses RFID cards which contain users fingerprint encrypted on it and interacts with the users through voice commands. ATM operates when sensor detects the presence of one person in the cabin. After scanning the RFID card, it will ask to select the mode like –normal or blind. User can select the respective mode through voice input, if blind mode is selected the balance check or cash withdraw can be done through voice input. Normal mode procedure is same as the existing ATM.
IMPACT OF EMOTIONAL INTELLIGENCE ON HUMAN RESOURCE MANAGEMENT PRACTICES AMONG...IAEME Publication
There is increasing acceptability of emotional intelligence as a major factor in personality assessment and effective human resource management. Emotional intelligence as the ability to build capacity, empathize, co-operate, motivate and develop others cannot be divorced from both effective performance and human resource management systems. The human person is crucial in defining organizational leadership and fortunes in terms of challenges and opportunities and walking across both multinational and bilateral relationships. The growing complexity of the business world requires a great deal of self-confidence, integrity, communication, conflict and diversity management to keep the global enterprise within the paths of productivity and sustainability. Using the exploratory research design and 255 participants the result of this original study indicates strong positive correlation between emotional intelligence and effective human resource management. The paper offers suggestions on further studies between emotional intelligence and human capital development and recommends for conflict management as an integral part of effective human resource management.
VISUALISING AGING PARENTS & THEIR CLOSE CARERS LIFE JOURNEY IN AGING ECONOMYIAEME Publication
Our life journey, in general, is closely defined by the way we understand the meaning of why we coexist and deal with its challenges. As we develop the "inspiration economy", we could say that nearly all of the challenges we have faced are opportunities that help us to discover the rest of our journey. In this note paper, we explore how being faced with the opportunity of being a close carer for an aging parent with dementia brought intangible discoveries that changed our insight of the meaning of the rest of our life journey.
A STUDY ON THE IMPACT OF ORGANIZATIONAL CULTURE ON THE EFFECTIVENESS OF PERFO...IAEME Publication
The main objective of this study is to analyze the impact of aspects of Organizational Culture on the Effectiveness of the Performance Management System (PMS) in the Health Care Organization at Thanjavur. Organizational Culture and PMS play a crucial role in present-day organizations in achieving their objectives. PMS needs employees’ cooperation to achieve its intended objectives. Employees' cooperation depends upon the organization’s culture. The present study uses exploratory research to examine the relationship between the Organization's culture and the Effectiveness of the Performance Management System. The study uses a Structured Questionnaire to collect the primary data. For this study, Thirty-six non-clinical employees were selected from twelve randomly selected Health Care organizations at Thanjavur. Thirty-two fully completed questionnaires were received.
Living in 21st century in itself reminds all of us the necessity of police and its administration. As more and more we are entering into the modern society and culture, the more we require the services of the so called ‘Khaki Worthy’ men i.e., the police personnel. Whether we talk of Indian police or the other nation’s police, they all have the same recognition as they have in India. But as already mentioned, their services and requirements are different after the like 26th November, 2008 incidents, where they without saving their own lives has sacrificed themselves without any hitch and without caring about their respective family members and wards. In other words, they are like our heroes and mentors who can guide us from the darkness of fear, militancy, corruption and other dark sides of life and so on. Now the question arises, if Gandhi would have been alive today, what would have been his reaction/opinion to the police and its functioning? Would he have some thing different in his mind now what he had been in his mind before the partition or would he be going to start some Satyagraha in the form of some improvement in the functioning of the police administration? Really these questions or rather night mares can come to any one’s mind, when there is too much confusion is prevailing in our minds, when there is too much corruption in the society and when the polices working is also in the questioning because of one or the other case throughout the India. It is matter of great concern that we have to thing over our administration and our practical approach because the police personals are also like us, they are part and parcel of our society and among one of us, so why we all are pin pointing towards them.
A STUDY ON TALENT MANAGEMENT AND ITS IMPACT ON EMPLOYEE RETENTION IN SELECTED...IAEME Publication
The goal of this study was to see how talent management affected employee retention in the selected IT organizations in Chennai. The fundamental issue was the difficulty to attract, hire, and retain talented personnel who perform well and the gap between supply and demand of talent acquisition and retaining them within the firms. The study's main goals were to determine the impact of talent management on employee retention in IT companies in Chennai, investigate talent management strategies that IT companies could use to improve talent acquisition, performance management, career planning and formulate retention strategies that the IT firms could use. The respondents were given a structured close-ended questionnaire with the 5 Point Likert Scale as part of the study's quantitative research design. The target population consisted of 289 IT professionals. The questionnaires were distributed and collected by the researcher directly. The Statistical Package for Social Sciences (SPSS) was used to collect and analyse the questionnaire responses. Hypotheses that were formulated for the various areas of the study were tested using a variety of statistical tests. The key findings of the study suggested that talent management had an impact on employee retention. The studies also found that there is a clear link between the implementation of talent management and retention measures. Management should provide enough training and development for employees, clarify job responsibilities, provide adequate remuneration packages, and recognise employees for exceptional performance.
ATTRITION IN THE IT INDUSTRY DURING COVID-19 PANDEMIC: LINKING EMOTIONAL INTE...IAEME Publication
Globally, Millions of dollars were spent by the organizations for employing skilled Information Technology (IT) professionals. It is costly to replace unskilled employees with IT professionals possessing technical skills and competencies that aid in interconnecting the business processes. The organization’s employment tactics were forced to alter by globalization along with technological innovations as they consistently diminish to remain lean, outsource to concentrate on core competencies along with restructuring/reallocate personnel to gather efficiency. As other jobs, organizations or professions have become reasonably more appropriate in a shifting employment landscape, the above alterations trigger both involuntary as well as voluntary turnover. The employee view on jobs is also afflicted by the COVID-19 pandemic along with the employee-driven labour market. So, having effective strategies is necessary to tackle the withdrawal rate of employees. By associating Emotional Intelligence (EI) along with Talent Management (TM) in the IT industry, the rise in attrition rate was analyzed in this study. Only 303 respondents were collected out of 350 participants to whom questionnaires were distributed. From the employees of IT organizations located in Bangalore (India), the data were congregated. A simple random sampling methodology was employed to congregate data as of the respondents. Generating the hypothesis along with testing is eventuated. The effect of EI and TM along with regression analysis between TM and EI was analyzed. The outcomes indicated that employee and Organizational Performance (OP) were elevated by effective EI along with TM.
INFLUENCE OF TALENT MANAGEMENT PRACTICES ON ORGANIZATIONAL PERFORMANCE A STUD...IAEME Publication
By implementing talent management strategy, organizations would have the option to retain their skilled professionals while additionally working on their overall performance. It is the course of appropriately utilizing the ideal individuals, setting them up for future top positions, exploring and dealing with their performance, and holding them back from leaving the organization. It is employee performance that determines the success of every organization. The firm quickly obtains an upper hand over its rivals in the event that its employees having particular skills that cannot be duplicated by the competitors. Thus, firms are centred on creating successful talent management practices and processes to deal with the unique human resources. Firms are additionally endeavouring to keep their top/key staff since on the off chance that they leave; the whole store of information leaves the firm's hands. The study's objective was to determine the impact of talent management on organizational performance among the selected IT organizations in Chennai. The study recommends that talent management limitedly affects performance. On the off chance that this talent is appropriately management and implemented properly, organizations might benefit as much as possible from their maintained assets to support development and productivity, both monetarily and non-monetarily.
A STUDY OF VARIOUS TYPES OF LOANS OF SELECTED PUBLIC AND PRIVATE SECTOR BANKS...IAEME Publication
Banking regulations act of India, 1949 defines banking as “acceptance of deposits for the purpose of lending or investment from the public, repayment on demand or otherwise and withdrawable through cheques, drafts order or otherwise”, the major participants of the Indian financial system are commercial banks, the financial institution encompassing term lending institutions. Investments institutions, specialized financial institution and the state level development banks, non banking financial companies (NBFC) and other market intermediaries such has the stock brokers and money lenders are among the oldest of the certain variants of NBFC and the oldest market participants. The asset quality of banks is one of the most important indicators of their financial health. The Indian banking sector has been facing severe problems of increasing Non- Performing Assets (NPAs). The NPAs growth directly and indirectly affects the quality of assets and profitability of banks. It also shows the efficiency of banks credit risk management and the recovery effectiveness. NPA do not generate any income, whereas, the bank is required to make provisions for such as assets that why is a double edge weapon. This paper outlines the concept of quality of bank loans of different types like Housing, Agriculture and MSME loans in state Haryana of selected public and private sector banks. This study is highlighting problems associated with the role of commercial bank in financing Small and Medium Scale Enterprises (SME). The overall objective of the research was to assess the effect of the financing provisions existing for the setting up and operations of MSMEs in the country and to generate recommendations for more robust financing mechanisms for successful operation of the MSMEs, in turn understanding the impact of MSME loans on financial institutions due to NPA. There are many research conducted on the topic of Non- Performing Assets (NPA) Management, concerning particular bank, comparative study of public and private banks etc. In this paper the researcher is considering the aggregate data of selected public sector and private sector banks and attempts to compare the NPA of Housing, Agriculture and MSME loans in state Haryana of public and private sector banks. The tools used in the study are average and Anova test and variance. The findings reveal that NPA is common problem for both public and private sector banks and is associated with all types of loans either that is housing loans, agriculture loans and loans to SMES. NPAs of both public and private sector banks show the increasing trend. In 2010-11 GNPA of public and private sector were at same level it was 2% but after 2010-11 it increased in many fold and at present there is GNPA in some more than 15%. It shows the dark area of Indian banking sector.
EXPERIMENTAL STUDY OF MECHANICAL AND TRIBOLOGICAL RELATION OF NYLON/BaSO4 POL...IAEME Publication
An experiment conducted in this study found that BaSO4 changed Nylon 6's mechanical properties. By changing the weight ratios, BaSO4 was used to make Nylon 6. This Researcher looked into how hard Nylon-6/BaSO4 composites are and how well they wear. Experiments were done based on Taguchi design L9. Nylon-6/BaSO4 composites can be tested for their hardness number using a Rockwell hardness testing apparatus. On Nylon/BaSO4, the wear behavior was measured by a wear monitor, pinon-disc friction by varying reinforcement, sliding speed, and sliding distance, and the microstructure of the crack surfaces was observed by SEM. This study provides significant contributions to ultimate strength by increasing BaSO4 content up to 16% in the composites, and sliding speed contributes 72.45% to the wear rate
ROLE OF SOCIAL ENTREPRENEURSHIP IN RURAL DEVELOPMENT OF INDIA - PROBLEMS AND ...IAEME Publication
The majority of the population in India lives in villages. The village is the back bone of the country. Village or rural industries play an important role in the national economy, particularly in the rural development. Developing the rural economy is one of the key indicators towards a country’s success. Whether it be the need to look after the welfare of the farmers or invest in rural infrastructure, Governments have to ensure that rural development isn’t compromised. The economic development of our country largely depends on the progress of rural areas and the standard of living of rural masses. Village or rural industries play an important role in the national economy, particularly in the rural development. Rural entrepreneurship is based on stimulating local entrepreneurial talent and the subsequent growth of indigenous enterprises. It recognizes opportunity in the rural areas and accelerates a unique blend of resources either inside or outside of agriculture. Rural entrepreneurship brings an economic value to the rural sector by creating new methods of production, new markets, new products and generate employment opportunities thereby ensuring continuous rural development. Social Entrepreneurship has the direct and primary objective of serving the society along with the earning profits. So, social entrepreneurship is different from the economic entrepreneurship as its basic objective is not to earn profits but for providing innovative solutions to meet the society needs which are not taken care by majority of the entrepreneurs as they are in the business for profit making as a sole objective. So, the Social Entrepreneurs have the huge growth potential particularly in the developing countries like India where we have huge societal disparities in terms of the financial positions of the population. Still 22 percent of the Indian population is below the poverty line and also there is disparity among the rural & urban population in terms of families living under BPL. 25.7 percent of the rural population & 13.7 percent of the urban population is under BPL which clearly shows the disparity of the poor people in the rural and urban areas. The need to develop social entrepreneurship in agriculture is dictated by a large number of social problems. Such problems include low living standards, unemployment, and social tension. The reasons that led to the emergence of the practice of social entrepreneurship are the above factors. The research problem lays upon disclosing the importance of role of social entrepreneurship in rural development of India. The paper the tendencies of social entrepreneurship in India, to present successful examples of such business for providing recommendations how to improve situation in rural areas in terms of social entrepreneurship development. Indian government has made some steps towards development of social enterprises, social entrepreneurship, and social in- novation, but a lot remains to be improved.
OPTIMAL RECONFIGURATION OF POWER DISTRIBUTION RADIAL NETWORK USING HYBRID MET...IAEME Publication
Distribution system is a critical link between the electric power distributor and the consumers. Most of the distribution networks commonly used by the electric utility is the radial distribution network. However in this type of network, it has technical issues such as enormous power losses which affect the quality of the supply. Nowadays, the introduction of Distributed Generation (DG) units in the system help improve and support the voltage profile of the network as well as the performance of the system components through power loss mitigation. In this study network reconfiguration was done using two meta-heuristic algorithms Particle Swarm Optimization and Gravitational Search Algorithm (PSO-GSA) to enhance power quality and voltage profile in the system when simultaneously applied with the DG units. Backward/Forward Sweep Method was used in the load flow analysis and simulated using the MATLAB program. Five cases were considered in the Reconfiguration based on the contribution of DG units. The proposed method was tested using IEEE 33 bus system. Based on the results, there was a voltage profile improvement in the system from 0.9038 p.u. to 0.9594 p.u.. The integration of DG in the network also reduced power losses from 210.98 kW to 69.3963 kW. Simulated results are drawn to show the performance of each case.
APPLICATION OF FRUGAL APPROACH FOR PRODUCTIVITY IMPROVEMENT - A CASE STUDY OF...IAEME Publication
Manufacturing industries have witnessed an outburst in productivity. For productivity improvement manufacturing industries are taking various initiatives by using lean tools and techniques. However, in different manufacturing industries, frugal approach is applied in product design and services as a tool for improvement. Frugal approach contributed to prove less is more and seems indirectly contributing to improve productivity. Hence, there is need to understand status of frugal approach application in manufacturing industries. All manufacturing industries are trying hard and putting continuous efforts for competitive existence. For productivity improvements, manufacturing industries are coming up with different effective and efficient solutions in manufacturing processes and operations. To overcome current challenges, manufacturing industries have started using frugal approach in product design and services. For this study, methodology adopted with both primary and secondary sources of data. For primary source interview and observation technique is used and for secondary source review has done based on available literatures in website, printed magazines, manual etc. An attempt has made for understanding application of frugal approach with the study of manufacturing industry project. Manufacturing industry selected for this project study is Mahindra and Mahindra Ltd. This paper will help researcher to find the connections between the two concepts productivity improvement and frugal approach. This paper will help to understand significance of frugal approach for productivity improvement in manufacturing industry. This will also help to understand current scenario of frugal approach in manufacturing industry. In manufacturing industries various process are involved to deliver the final product. In the process of converting input in to output through manufacturing process productivity plays very critical role. Hence this study will help to evolve status of frugal approach in productivity improvement programme. The notion of frugal can be viewed as an approach towards productivity improvement in manufacturing industries.
A MULTIPLE – CHANNEL QUEUING MODELS ON FUZZY ENVIRONMENTIAEME Publication
In this paper, we investigated a queuing model of fuzzy environment-based a multiple channel queuing model (M/M/C) ( /FCFS) and study its performance under realistic conditions. It applies a nonagonal fuzzy number to analyse the relevant performance of a multiple channel queuing model (M/M/C) ( /FCFS). Based on the sub interval average ranking method for nonagonal fuzzy number, we convert fuzzy number to crisp one. Numerical results reveal that the efficiency of this method. Intuitively, the fuzzy environment adapts well to a multiple channel queuing models (M/M/C) ( /FCFS) are very well.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Design and optimization of ion propulsion dronebjmsejournal
Electric propulsion technology is widely used in many kinds of vehicles in recent years, and aircrafts are no exception. Technically, UAVs are electrically propelled but tend to produce a significant amount of noise and vibrations. Ion propulsion technology for drones is a potential solution to this problem. Ion propulsion technology is proven to be feasible in the earth’s atmosphere. The study presented in this article shows the design of EHD thrusters and power supply for ion propulsion drones along with performance optimization of high-voltage power supply for endurance in earth’s atmosphere.
Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
Rainfall intensity duration frequency curve statistical analysis and modeling...bijceesjournal
Using data from 41 years in Patna’ India’ the study’s goal is to analyze the trends of how often it rains on a weekly, seasonal, and annual basis (1981−2020). First, utilizing the intensity-duration-frequency (IDF) curve and the relationship by statistically analyzing rainfall’ the historical rainfall data set for Patna’ India’ during a 41 year period (1981−2020), was evaluated for its quality. Changes in the hydrologic cycle as a result of increased greenhouse gas emissions are expected to induce variations in the intensity, length, and frequency of precipitation events. One strategy to lessen vulnerability is to quantify probable changes and adapt to them. Techniques such as log-normal, normal, and Gumbel are used (EV-I). Distributions were created with durations of 1, 2, 3, 6, and 24 h and return times of 2, 5, 10, 25, and 100 years. There were also mathematical correlations discovered between rainfall and recurrence interval.
Findings: Based on findings, the Gumbel approach produced the highest intensity values, whereas the other approaches produced values that were close to each other. The data indicates that 461.9 mm of rain fell during the monsoon season’s 301st week. However, it was found that the 29th week had the greatest average rainfall, 92.6 mm. With 952.6 mm on average, the monsoon season saw the highest rainfall. Calculations revealed that the yearly rainfall averaged 1171.1 mm. Using Weibull’s method, the study was subsequently expanded to examine rainfall distribution at different recurrence intervals of 2, 5, 10, and 25 years. Rainfall and recurrence interval mathematical correlations were also developed. Further regression analysis revealed that short wave irrigation, wind direction, wind speed, pressure, relative humidity, and temperature all had a substantial influence on rainfall.
Originality and value: The results of the rainfall IDF curves can provide useful information to policymakers in making appropriate decisions in managing and minimizing floods in the study area.
Software Engineering and Project Management - Introduction, Modeling Concepts...Prakhyath Rai
Introduction, Modeling Concepts and Class Modeling: What is Object orientation? What is OO development? OO Themes; Evidence for usefulness of OO development; OO modeling history. Modeling
as Design technique: Modeling, abstraction, The Three models. Class Modeling: Object and Class Concept, Link and associations concepts, Generalization and Inheritance, A sample class model, Navigation of class models, and UML diagrams
Building the Analysis Models: Requirement Analysis, Analysis Model Approaches, Data modeling Concepts, Object Oriented Analysis, Scenario-Based Modeling, Flow-Oriented Modeling, class Based Modeling, Creating a Behavioral Model.
2. Suhail Al-Awis and Ali Y. Fattah
http://www.iaeme.com/IJECET/index.asp 88 editor@iaeme.com
Extensive addressing of the coherent optical transmission systems in the eighties
of the last century was resulted due to highly sensitive receivers [2,3]. However, 20
years later coherent technologies has been delayed [4-6]. Higher order modulation
formats detected by coherent detection like PDM-QPSK, PDM-8PSK, PDM-8QAM,
PDM-16QAM and PDM-36QAM use all possible degree of freedom of the optical
wave for information encoding via IQ-modulators to access in-phase and quadrature-
phase components for both polarizations to best utilize the available bandwidth more
than binary alternatives and boost the capacity without the installation of any extra
fibers [7-13]. Efficient modulation formats such PSK and QAM which are
implemented with the aid of DSP receivers attracted the interests of investigation until
2005 [14]. Electronic compensation of the transmission impairments as powerful as
traditional optical techniques was enabled by fully accessing the optical wave
information [6].
Canonical model of a multi span long haul optical fiber transmission system is
shown in Figure 1 (a). Before the invention of the optical amplifiers, optical-
electrical-optical (O-E-O) conversion take place to compensate the channel
impairments and the electrical signal is re-amplified, re-shaped, and re-timed (3R
regeneration) before converted back to optical format. O-E-O conversion is expensive
and requires priori knowledge of the transmitted signal such as its symbol rate at the
repeater in order to perform 3R regeneration [15].
Figure 1 (a) Canonical model of a multi-span long-haul fiber channel, (b) Multispan long-
haul fiber channel with inline amplification and dispersion compensation
Invention of the erbium doped fiber amplifier (EDFA) in the 1990s stalled the
development in coherent optical systems, which enabled repeaterless transmission
over long-haul distances. The combination of the C-band (1530–1570 nm) and L-band
(1570–1610 nm) spectrums resulted in 10 THz of bandwidth. Rapid growth of
internet applications traffic, such as multimedia sharing, made this bandwidth
becoming rapidly fully utilized. Thus, there is renewed interest in high-spectral-
efficiency transmission over long distances [16].
New challenges ahead the new channel configuration, in which optical signals are
propagated over thousands of kilometers of fiber, such as the need to compensate
chromatic dispersion (CD). A typical long-haul system model is shown in Figure 1
(b), with inline amplification and dispersion compensation fiber (DCF) after every
span. Furthermore, as the number of wavelength division multiplexed (WDM)
channels per fiber increase, and as the data rate per channel increase, fiber
nonlinearity, (PMD) and other impairments which were previously not important
became limiting factors [15]. Transmission impairments in optical fiber
communication can be categorized into linear and nonlinear impairments. Linear
3. Characterization of Physical Layer Impairments Impact on Optical Fiber Transmission
Systems
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impairments include attenuation, amplified spontaneous emission (ASE) noise,
polarization mode dispersion (PMD), chromatic dispersion (CD) and linear crosstalk
in WDM systems from optical de-multiplexers/ filters and wavelength routers. On the
other hand self-phase modulation, cross-phase modulation, cross polarization
modulation classified as nonlinear impairments. To understand these impairments, the
propagation of a pulse in an optical fiber channel which is described by nonlinear
Schrödinger equation [17] should be understood clearly:
𝜕𝐴
𝜕𝑍
+
𝛼
2
𝐴 +
𝑖
2
𝛽2
𝜕2
𝐴
𝜕𝑇2
= 𝑖𝛾|𝐴|2
𝐴 (1)
Where is the signal amplitude, is the distance of the fiber, is the attenuation
coefficient, is group velocity dispersion parameter and is the Kerr nonlinear
coefficient.
2. THEORITECAL BACKGROUND
2.1 Linear Impairments
Modelling of single mode fiber in the absence of the nonlinearity can be
considered as linear time invariant (LTI) channel with dually polarized inputs and
output as shown in Figure 2 [15].
Figure 2 Dual-polarization linear channel modelling
The channel can be characterized by its impulse response matrix as shown in
equation 2.
ℎ(𝑡) = (
ℎ11(𝑡) ℎ12(𝑡)
ℎ21(𝑡) ℎ22(𝑡)
) 𝐇(𝛚) = (
𝐻11(𝜔) 𝐻12(𝜔)
𝐻21(𝜔) 𝐻22(𝜔)
) (2)
where hij(t) is the response of the i-th output polarization due to applied impulse at
the j-th input polarization of the fiber. H(ɷ) and h(t) are Jones matrices with
frequency-dependent and time-dependent elements, respectively. The matrix
description of the channel is sufficient for describing CD, polarization-dependent loss
(PDL), all PMD orders, optical filtering effects, sampling time error, and any other
linear impairment [18].
2.1.1 Fiber attenuation
Fiber loss parameter α(z), which describes the attenuation of the optical signal
power while propagating through the fiber channel as shown in equation (3).
𝛼(𝑧) = −
10
𝑧
𝑙𝑜𝑔10 (
𝑃𝑜𝑢𝑡
𝑃𝑖𝑛
) (3)
Where z is the length of the fiber channel, Pout and Pin are the output and input
optical powers of transmission fiber span respectively. It is mainly caused by material
absorption and Rayleigh scattering effects, but it is also a function of carrier signal
wavelength [19].
Etx(t) =
=Erx(t)
Erx,1(t)
Erx,2(t)
Etx,1(t)
Etx,2(t)
H=
h11 h12
h21 h22
Linear Channel
4. Suhail Al-Awis and Ali Y. Fattah
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2.1.2 Chromatic dispersion
In [17] Linear Schrödinger Equation (LSE) described, where β can be expanded
around the carrier frequency into a Taylor series approximation, truncated at the 3rd
term as in equation (4):
𝜕𝐴
𝜕𝑧
+
𝛼
2
𝐴 + 𝛽1
𝜕𝐴
𝜕𝑡
+
i
2
𝛽2
𝜕2A
𝜕𝑡2 −
1
6
𝛽3
𝜕3 𝐴
𝜕𝑡3 = 0 (4)
Here the group velocity ʋG is related to β1 and therefore calculate the speed the
envelope of an optical signal propagates along the fiber:
𝛽1 =
1
𝑣 𝐺
=
1
𝑐
(𝑛 + 𝜔
𝑑𝑛
𝑑𝜔
) (5)
With c is the light speed in vacuum, n is the linear refractive index and ɷ is the
optical frequency. β2 is the group-velocity dispersion (GVD) parameter, which
broadens the travelling pulse:
𝛽2
1
𝑐
(2
𝑑𝑛
𝑑𝜔
+ 𝜔
𝑑2 𝑛
𝑑𝜔2) (6)
D is defined as the dispersion parameter of the first derivative of β1 with respect to
the optical wavelength λ:
𝐷 =
𝑑𝛽1
𝑑𝜆
= −
2𝜋𝑐
𝜆2 𝛽2 ≈
𝜆𝑑2 𝑛
𝑐𝑑𝜆2 (7)
β3=dβ2/dɷ is the GVD slope parameter, which relates to the dispersion slope
parameter S by:
𝑆 =
𝑑𝛽2
𝑑𝜆
= −
4𝜋𝑐2
𝜆3 𝛽2 + (
2𝜋𝑐
𝜆2 )
2
𝛽3 (8)
At the zero dispersion wavelength (β2 = 0) region, the GVD slope becomes
especially important for transmission. The retarded time frame T = t – z/ʋG is
introduced, which propagates with the signal at the group velocity dropping β1 from
the equation. Finally, the GVD slope influence can be neglected by considering
standard single-mode fibers (SMF) or other types with sufficiently high GVD:
𝜕𝐴
𝜕𝑧
+
𝛼
2
𝐴 +
𝑖
2
𝛽2
𝜕2 𝐴
𝜕𝑇2 = 0 (9)
The total dispersion profile of an optical fiber can be evaluated by material and
waveguide dispersion respectively (DM) and (DW). For the SSMF the summation of
these parameters resulted in a dispersion profile shown in Figure 3, with the zero
dispersion wavelength at 1324 nm and D=16ps/km/nm at 1550 nm [20].
Figure 3 Dispersion characteristic of a typical SMF as a function of wavelength and
frequency.
5. Characterization of Physical Layer Impairments Impact on Optical Fiber Transmission
Systems
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2.1.3 Polarization mode dispersion
Polarization of a light considers as a property of electromagnetic waves that
shows the transverse electric field orientation. X and Y are two orthogonal
polarization states exists in SMF. Stokes parameters can be used to describe the
representation of light polarization, which expressed straightforward by using
Poincaré sphere. This sphere consists of four parameters in terms of optical power as
shown in Figure 4 [21].
Figure 4 Poincaré sphere
SMF supports the transmission of two orthogonal polarization-modes, but
temperature fluctuations and random birefringence resulted from mechanical stress
changes the states-of-polarization (SOP) and, hence, the GVD to vary with time and
along the fiber length [22]. A typical fiber length ranges from hundreds of meters up
to few kilometers along which the SOP varies. Mathematically, the modal
birefringence, Bm described in equation (10):
𝐵 𝑚 =
|βx−βy|λ
2π
= |𝑛 𝑥 − 𝑛 𝑦| (10)
Where nx and ny as the effective refractive index of both modes. βx and βy are the
modes propagation constants. The axis with larger group velocity described as the fast
axis while the other with smaller group velocity denoted as the slow axis, referring to
Figure 5 for a linearly polarized optical pulse launched at 45o
into a fiber. The
difference between arrival times of the two pulses is referred to as differential group
delay ΔJ (DGD) which have Maxwellian distribution around mean DGD-value 〈ΔJ〉.
[20].
Figure 5 Random birefringence and resulting DGD for optical pulse launched into a fiber
at 45o
with respect to slow axis.
The PMD-induced pulse broadening can be evaluated from the DGD between the
two polarization components after averaging over random birefringence [23] as
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Δ𝑇 = 𝐷 𝑃√𝐿 (11)
Where DP is the fiber PMD parameter measured in ps/√km. While in [24] PMD
power penalty can be estimated as,
𝑝𝑒𝑛 𝑃𝑀𝐷 = 10.2𝐵2
𝐷 𝑃
2
𝐿 (12)
Where B as the signal bit rate.
2.1.4 Linear cross talk in WDM systems
It arises in wavelength routers, optical filters and de-multiplexing devices. In
WDM systems a signal at a particular wavelength is de-multiplexed at the receiver by
means of an optical filter. Wavelength components outside the signal optical
bandwidth is not completely suppressed by the optical filters. Thus power from
adjacent channels in a WDM system leaks into the central channel causing what is
known as a cross talk penalty in the central channel. This penalty increases as the
number of multiplexed WDM channels is increasing. It is called out of band cross talk
since this crosstalk is generated by out of bandwidth of the central channel band.
Linear out of band crosstalk is shown in Figure 6 [25]. For a WDM system with N
channels the total generated photocurrent by the optical signal filtered at the receiver
is given by [20]
I = RmPm + ∑ RnTmnPn
N
n≠m ≡ Ich + IX (13)
where Pm is the power of the mth
channel or the filtered channel, Pn is the power of
the nth
neighboring channel, and R are the receiver photo responsitivities and T is the
receiver transmissivity of the nth
channel when the mth
channel is filtered. The
current due to the filtered channel power (Ich) and the current due to power of the
crosstalk from the neighboring channels is (IX). The current must be increases by to
keep the performance of the system in terms of eye opening.
Figure 6 Linear cross talk in WDM systems
The power penalty is thus given by
δX =
Ich+IX
IX
= 1 +
Ich
IX
(14)
δX is a measure of out of band crosstalk. Another source of crosstalk penalty in
WDM systems which is the wavelength routers based on AWGs. The operation of a
4x4 AWG router is depicted in Figure 7.
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Figure 7 4x4 AWG Router
Where letters a,b,c and d refer to the port and the subscripts 1,2,3 and 4 refer to
the wavelength number. For ideal conditions the wavelengths at the input ports are
routed to the output ports according to the scheme shown in Figure 7. However due to
imperfections in the AWG structure each wavelength in the output port suffers from
in band crosstalk which appears due to power leaking from other ports at the same
wavelength and the out of band crosstalk which appears from the wavelength
channels in the same port [25]. The in-band crosstalk penalty for a WDM system with
N channels is given by [26] as shown in equation (15).
𝛿 𝑋 = −10 log10(1 − 𝑟𝑋
2
𝑄2) (15)
Where
𝑟𝑋
2
= 𝑋(𝑁 − 1)
N is the number of channels and -value is the measure of eye opening of the
receiver.
2.2. Non-Linear Impairments
Any dielectric subjected to light have nonlinear response for intense electromagnetic
fields, and hence the optical fibers. Although the silica is intrinsic and not a highly
nonlinear material, but the waveguide geometry that confines light into a small cross
sectional area over long haul fiber makes nonlinear effects very important in the
design step of modern lightwave systems [27].
Fiber nonlinearities classified either to nonlinear refractive index (Kerr effect) or
to nonlinear optical scattering .The Kerr effect take place in response to the
dependence of the index of refraction on light intensity. Fiber nonlinearities of this
type are self-phase modulation (SPM), cross-phase modulation (XPM), and four-wave
mixing (FWM).The stimulated scattering effects are caused by parametric interaction
between the light and materials.
There are two types of stimulated scattering effects: Stimulated Raman Scattering
(SRS) and stimulated Brillouin scattering (SBS). One difference between the
scattering effect and the Kerr effect is that, stimulated scattering has threshold power
level at which the nonlinear effects manifest themselves while Kerr effect does not
have such threshold [28].
Assuming that the SOP of the transmitted light is not maintained, it may be shown
that the threshold power PB due to Stimulated Brillouin scattering (SBS) is given as
in equation (16). While that resulted from the Stimulated Raman scattering (SRS) is
given in equation (17) [30].
𝑃𝐵 = 4.4 × 10−3
𝑑2
𝜆2
𝛼 𝑑𝐵 𝑣 (𝑤𝑎𝑡𝑡𝑠) (16)
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Where 𝑑 as the fiber core diameter and λ as the operating wavelength, both are
measured in µm, 𝛼 𝑑𝐵 is the fiber attenuation in dB per kilometer and ν is the source
bandwidth in GHz.
𝑃𝑅 = 5.9 × 10−2
𝑑2
𝜆𝛼 𝑑𝐵 (𝑤𝑎𝑡𝑡𝑠) (17)
Where 𝑑, 𝜆 and 𝛼 𝑑𝐵 are defined as in equation (16) above.
Decomposing the optical field A in equation (9) into three field components
interacting with each other A0, A1 and A2, each describes different WDM channel with
Δβ as the phase relationship between them. To highlight the influence of nonlinearity
restricted to small-signal distortions, equation (9) can be separated into three coupled
equations for WDM channel A0 [29]:
𝜕𝐴 𝑜
𝜕𝑧
+
𝛼
2
𝐴 𝑜 +
𝑖
2
𝛽2
𝜕2
𝐴 𝑜
𝜕𝑇2
= 𝑖𝛾|𝐴 𝑜|2
𝐴 𝑜 + 2𝑖𝛾(|𝐴1|2
+ |𝐴2|2)𝐴 𝑜 + 𝑖𝛾 ∑ 𝐴𝑙 𝐴 𝑚 𝐴𝑙+𝑚
∗
𝑒 𝑖∆𝛽𝑧
𝑙,𝑚≠0
3. SYSTEM MODEL AND SIMULATION RESULTS
3.1. Linear Impairments Characterization
3.1.1 Chromatic dispersion penalty measurements
The system model depicted in Figure 8, was developed in VPITransmission maker to
measure the impact of fiber dispersion for different alfa values of MZM on the BER
OSNR and OSNR penalty, which is defined as the difference in optical SNR that is
required to reach a certain target BER for the case of propagation over the system of 1
km under test and the back-to-back one. Linear interpolation is used to find the
correct OSNR values. The OSNR is varied by adjusting the signal power and keeping
the noise power constant. For this approach to work accurately enough, it is critical to
set the two attenuation values of the variable optical attenuator in front of the receiver
such that the target BER lays in between the two calculated BER values as shown in
figure. Simulation results that shows the effect of the OSNR on the BER for different
valued of MZM alfa factor which described the chirping behavior of the modulator
and the OSNR penalty for different values of dispersion is shown in Figure 9 (a) and
(b) respectively.
NRZ MZM
Modulator
GW Opt.
Noise
OOK
Rx
OSNR
OSNR
BER vs OSNR
Opt. Amp
Att. Mux
Only Disp.
accounted
After the Fiber
Link
Without Disp.
effect
Figure 8 System model for OSNR penalty measurements due to fiber dispersion
SPM XPM
FWM
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(a) (b)
Figure 9 Simulation results for OSNR penalty measurements (a) BER vs OSNR for different
values of MZM’s alfa factor (b) OSNR penalty due to fiber dispersion
3.1.2 Polarization mode dispersion penalty measurements
To characterize the effect of the PMD on the optical fiber transmission link, the
system model depicted in Figure 10 which is developed with VPITrasmission maker
is used for this purpose. It is shown how the SOP of a CW probe signal is changed by
the SOP of a CW or modulated pump signal along the fiber. To simplify the
simulation, dispersion-less and loss-less fiber with constant birefringence is used with
the following settings:
Loops = 20, Fiber Span = 5 km, Attenuation = 0 dB/m, Dispersion = 0 s/m^2.
SOP
Monitoring
Pump
Att. = 0
Disp. = 0
SPM = No
XPM = Yes
Birefringence = Constant
Mux
Probe
CW
CW
Poincare
NRZ
Figure 10 Three channels WDM system model to identify PMD effects
The Poincare SOP graph is shown in Figure 11 (a) for azimuth 15o
and ellipticity
of 10o
of the CW pump signal. A modification to the SOP of the CW pump signal was
made to observe the impact on the probe. Pump SOP changed to azimuth 25o
,
ellipticity 15o
as shown in Figure 11 (b). While in Figure 11 (c) the probe and CW
pump have same SOP at azimuth 25o
, Ellipticity 15o
.
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(a) (b) (c)
Figure 11 SOP of the probe and the pump signals (a) SOP at pump polarization az =15o
, Elp
= 10o
(b) SOP at pump polarization az = 25o
, Elp = 15o
(c) SOP at probe and pump
polarizations az = 25o
, Elp = 15o
If the CW pump is deactivated and the modulated (10G NRZ) pump is activated,
the depolarization of the probe is clearly observed as shown in Figure 12.
Figure 12 SOP of the Received Signals impacted by SOP of the NRZ-OOK Pump Signal.
3.1.3 Linear cross talk in WDM systems penalty measurements
To illustrate the impact of non-adjacent crosstalk in the NxN AWG on the BER
level in such NxN optical interconnection systems. Following the experimental setup
in [31], the beat crosstalk for only a single wavelength had been simulated with VPI
photonics simulator, using a single signal source divided into 16 paths by 1x16 power
splitter as shown in Figure 13 (a). Then one path is used as a source of the main
signal, while all the remaining paths are used as sources of same-wavelength
crosstalk. All sources are de-correlated from each other by using delay lines with
subsequently increasing time delays. After this the rest paths are connected to the
AWG's input ports, and the BER is measured for the main signal directed to the
AWG's first output port. Eye penalty diagrams for different values of cross talk
attenuations are shown in Figure 13 (b-d). Importantly, as is shown in [31], the
probability density distribution of the signal-crosstalk beat noise becomes Gaussian at
large number of crosstalk sources, N. This allows to employ in the simulation the
Gauss method for the BER estimation as shown in Figure 13 (e).
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(a) (b)
(C) (D)
(E)
Figure 13 Impact of Crosstalk in an Arrayed-Waveguide Grating Router (AWGR) on NxN
Optical Interconnection (a) System Model (b) Eye diag. at 25 dB XT att. (c) Eye diag. at 30
dB XT att. (e) Eye diag. at 35 dB XT att. (d) BER vs ROP for different values of XT att.
Another simulation for a WDM system modelled as in Figure 14 (a) to make a
comparison of BER degradations due to intraband and interband crosstalk of the same
attenuation level as shown in Figure 14 (b).
12. Suhail Al-Awis and Ali Y. Fattah
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(A) (B)
Figure 15 Comparison of BER degradation due to intraband and interband crosstalk of the
same level (a) System model (b) BER vs XT attenuation for different cases
3.1.3 Nonlinear impairments penalty measurements
The performance degradation due to Rayleigh and Brillouin scattering can be
reduced by separating the frequencies of the counter-propagating channels. In the
simulation setup of Figure 16 (a), the crosstalk is represented by the Rayleigh and
Brillouin distortions produced in the Universal Fiber. The system performance for
different input powers and channels separations is estimated with the Rx_OOK_BER
module as shown in Figure 16 (b).
(a)
(b)
Figure 16 Performance degradation due to Rayleigh and Brillouin scattering (a) Simulation
Setup (b) BER vs Channel Spacing for Different Channel Power Levels
BER vs Ch.
Separation
Opt. Mux
110 km Fiber
NRZ
NRZ
OOK
Rx
Universal
Fiber
Tx 1
8x10 Gbps
Tx 2
8x10 Gbps
In_Fw
Bus
Out_Fw
In_Bw
Out_Bw
Opt. Filter
BER vs XT Att.
Opt. Att. to
Control XT
Opt. Att.
Mux
Desired Signal
λ1
NRZ
NRZ
NRZ
OOK
Rx
OOK
Rx
OOK
Rx
Intraband
Crosstalk Signal
(λ2 = λ1)
Interband Crosstalk Signal (λ3 ≠ λ1)
100GHz away from desired signal
Opt. Att. to
Control XT Mux
No Crosstalk
B-B
13. Characterization of Physical Layer Impairments Impact on Optical Fiber Transmission
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When pulse collision take place as shown in Figure 17 (b), one pulse walking
through a pulse on a different WDM channels the pulses will interact because they
both affect the index of the fiber along which they propagated causing XPM
impairment as shown in Figure 17 (c). The effect of the fiber's nonlinearity combined
with the dispersion of the fiber also causes shaping of a pulse, by its own effect on the
fiber's index. This is SPM which will compress a strong pulse, increasing its peak
amplitude refer to Figure 17 (d).
Finally the FWM impairment penalty characterization can be clearly observed
using VPITransmission maker simulation setup in Figure 18, which consist of 4 x 10
Gbit/s WDM transmission system over Dispersion Shifted Fiber (DSF). The
emergence of the FWM products outside the WDM signal bandwidths can be clearly
observed in terms of eye penalty and optical spectrum as shown in Figure 19 (a-b).
The WDM signal attenuation due to FWM penalty is shown in Figure 19 (c).
Figure 17 SPM and XPM Measurement (a) Simulation setup (b) Pulse collision of strong and
weak pulse (c) Strong pulse impact on weak pulse XPM (d) Weak pulse impact on strong
pulse SPM
Figure 18 Simulation Setup of a 4 x 10 Gbit/s WDM transmission system over DSF fiber to
characterize the FWM effect
(a)(b)
(d)(c)
ROP (dBm)
Vs
L (km)
NRZ
NRZ
NRZ
NRZ
Power
Meter
Power
Meter
Power
Meter
Power
Meter
1 km of DSF
Attenuation=0.2 dB/km
Opt. MUXOpt. MUX
14. Suhail Al-Awis and Ali Y. Fattah
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Figure 19 Emergence of FWM products (a) Eye penalty of the multiplexed signals (b)
Optical spectrums of the multiplexed signals (c) Power level of the received signals.
4. CONCLUSIONS
In this paper the physical layer impairments of the optical fiber transmission link
had been characterized using analytical modelling and verified using numerical
simulations. It is shown that linear impairments are deterministic and have
controllable impact on the performance of the transmission links in terms of BER,
OSNR and Eye penalty. But nonlinear impairments have nondeterministic and
partially controllable impact of the quality of transmission QoT of optical fiber
transmission links. Besides the analytical modeling techniques an empirical modelling
one which are based on numerical simulations or experimental results seems more
promising especially for online impairment measurement and impairment
compensation algorithms since empirical techniques will save more computational
cost.
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