This document discusses using decision feedback equalization to enhance the performance of optical communication systems. It proposes using a fractionally spaced decision feedback equalizer (FSDFE) combined with activity detection guidance (ADG) and tap decoupling (TD) to improve the equalizer's effectiveness. The FSDFE replaces the symbol spaced feedback filter with a fractionally spaced feedback filter to enhance stability, steady-state error performance, and convergence rate. Adding ADG and TD further improves the steady-state error performance and convergence rate by detecting active taps in the channel impulse response. Simulation results show the FSDFE with ADG and TD offers superior performance to the FSDFE without these techniques, with improved compensation of amplitude distortion.
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
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.
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.
P ERFORMANCE A NALYSIS O F A DAPTIVE N OISE C ANCELLER E MPLOYING N LMS A LG...ijwmn
n voice communication systems, noise cancellation
using adaptive digital filter is a renowned techniq
ue
for extracting desired speech signal through elimin
ating noise from the speech signal corrupted by noi
se.
In this paper, the performance of adaptive noise ca
nceller of Finite Impulse Response (FIR) type has b
een
analysed employing NLMS (Normalized Least Mean Squa
re) algorithm.
An extensive study has been made
to investigate the effects of different parameters,
such as number of filter coefficients, number of s
amples,
step size, and input noise level, on the performanc
e of the adaptive noise cancelling system. All the
results
have been obtained using computer simulations built
on MATLAB platform.
SαS noise suppression for OFDM wireless communication in rayleight channel IJECEIAES
Orthogonal frequency division multiplexing (OFDM) is a form of multicarrier transmission technique widely used in the modern wireless network to achieve high-speed data transmission with good spectral efficiency. However, in impulsive noise environement BER performances of these systems, originally designed for a Gaussian noise model, are much degraded. In this paper, a new symmetric-alpha-stable (SαS) noise suppression technique based conjointly on adaptive modulation, convolutional coding (AMC) and Recursive Least Square (RLS) filtering is presented. The proposed scheme is applied on OFDM system in Rayleigh fading channel. The transmissions are analyzed under different combinations of digital modulation schemes (BPSK, QPSK, 16-QAM, 64-QAM) and convolutional code rates (1/2, 2/3, 3/4). Simulation results show that our proposed hybrid technique provides effective impulsive noise cancelation in OFDM system and exhibits better BER performance.
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
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.
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.
P ERFORMANCE A NALYSIS O F A DAPTIVE N OISE C ANCELLER E MPLOYING N LMS A LG...ijwmn
n voice communication systems, noise cancellation
using adaptive digital filter is a renowned techniq
ue
for extracting desired speech signal through elimin
ating noise from the speech signal corrupted by noi
se.
In this paper, the performance of adaptive noise ca
nceller of Finite Impulse Response (FIR) type has b
een
analysed employing NLMS (Normalized Least Mean Squa
re) algorithm.
An extensive study has been made
to investigate the effects of different parameters,
such as number of filter coefficients, number of s
amples,
step size, and input noise level, on the performanc
e of the adaptive noise cancelling system. All the
results
have been obtained using computer simulations built
on MATLAB platform.
SαS noise suppression for OFDM wireless communication in rayleight channel IJECEIAES
Orthogonal frequency division multiplexing (OFDM) is a form of multicarrier transmission technique widely used in the modern wireless network to achieve high-speed data transmission with good spectral efficiency. However, in impulsive noise environement BER performances of these systems, originally designed for a Gaussian noise model, are much degraded. In this paper, a new symmetric-alpha-stable (SαS) noise suppression technique based conjointly on adaptive modulation, convolutional coding (AMC) and Recursive Least Square (RLS) filtering is presented. The proposed scheme is applied on OFDM system in Rayleigh fading channel. The transmissions are analyzed under different combinations of digital modulation schemes (BPSK, QPSK, 16-QAM, 64-QAM) and convolutional code rates (1/2, 2/3, 3/4). Simulation results show that our proposed hybrid technique provides effective impulsive noise cancelation in OFDM system and exhibits better BER performance.
Speech Enhancement Using Spectral Flatness Measure Based Spectral SubtractionIOSRJVSP
This paper is aimed to reduce background noise introduced in speech signal during capture, storage, transmission and processing using Spectral Subtraction algorithm. To consider the fact that colored noise corrupts the speech signal non-uniformly over different frequency bands, Multi-Band Spectral Subtraction (MBSS) approach is exploited wherein amount of noise subtracted from noisy speech signal is decided by a weighting factor. Choice of optimal values of weights decides the performance of the speech enhancement system. In this paper weights are decided based on SFM (Spectral Flatness Measure) than conventional SNR (Signal to Noise Ratio) based rule. Since SFM is able to provide true distinction between speech signal and noise signal. Spectrogram, Mean Opinion Score show that speech enhanced from proposed SFM based MBSS possess better perceptual quality and improved intelligibility than existing SNR based MBSS
Comparative performance analysis of channel normalization techniqueseSAT Journals
Abstract A major part of the interaction between humans takes place via speech communication. The speech signal carries both useful and unwanted information. Processing of such signals involve enhancing the useful information. The intelligibility of speech signals is significantly reduced due to the presence of unwanted information such as noise. Channel normalization algorithms suppress such additive noise introduced in the speech signals by transmission channel or by recording environment conditions. Enhancing the quality and intelligibility of speech signals improve the performance of speech systems such as Automatic speech recognition (ASR) , voice communication and hearing aids to name the few. Based on the experimental results the comparative analysis of channel normalization techniques have been presented in this paper to find out the most suitable algorithm for enhancing the speech signals. Keywords: Cepstral Mean Normalization, Spectral Subtraction, Weiner filter, Signal to Noise Ratio
International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Improvement of minimum tracking in Minimum Statistics noise estimation methodCSCJournals
Noise spectrum estimation is a fundamental component of speech enhancement and speech recognition systems. In this paper we propose a new method for minimum tracking in Minimum Statistics (MS) noise estimation method. This noise estimation algorithm is proposed for highly nonstationary noise environments. This was confirmed with formal listening tests which indicated that the proposed noise estimation algorithm when integrated in speech enhancement was preferred over other noise estimation algorithms.
Performance Evaluation of Adaptive Filters Structures for Acoustic Echo Cance...CSCJournals
We have designed and simulated an acoustic echo cancellation system for conferencing. This system is based upon a least-mean-square (LMS) adaptive algorithm and uses multi filter technique. A comparative study of both structure has been carried out and it is found that this new multi-filter converge faster than similar single long adaptive filter. Index Terms: LMS,Multiple sub filter ,Echo cancellation
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.
Reduction of Frequency offset Using Joint Clock for OFDM Based Cellular Syste...IJRST Journal
This project addresses the problem of clock synchronization between a base station (BS) and a mobile station (MS). A conventional technique for clock synchronization is that the MS clock is derived from the downlink signal originated from a base station. In cellular systems, a base station and mobile stations need to be synchronized before data exchange. Since the base station clock reference is more accurate, a mobile station typically derives its clock reference from the base station. But the carrier frequency offset due to Doppler shift may have harmful effects on the local clock derivation. This project proposes a joint clock and frequency synchronization technique between a base station and a mobile station, which is effective even with Doppler shift. We derive the joint estimation algorithm by analyzing the phase and the amplitude distortion caused by the sampling frequency offset and the carrier frequency offset. Simulation results showing the effectiveness of the proposed algorithm will also be presented.
Performance Analysis of Acoustic Echo Cancellation TechniquesIJERA Editor
Mainly, the adaptive filters are implemented in time domain which works efficiently in most of the applications. But in many applications the impulse response becomes too large, which increases the complexity of the adaptive filter beyond a level where it can no longer be implemented efficiently in time domain. An example of where this can happen would be acoustic echo cancellation (AEC) applications. So, there exists an alternative solution i.e. to implement the filters in frequency domain. AEC has so many applications in wide variety of problems in industrial operations, manufacturing and consumer products. Here in this paper, a comparative analysis of different acoustic echo cancellation techniques i.e. Frequency domain adaptive filter (FDAF), Least mean square (LMS), Normalized least mean square (NLMS) &Sign error (SE) is presented. The results are compared with different values of step sizes and the performance of these techniques is measured in terms of Error rate loss enhancement (ERLE), Mean square error (MSE)& Peak signal to noise ratio (PSNR).
Performance evaluation of different spectrum sensing techniques for realistic...ijwmn
In this paper, the performance assessment of five different detection techniques from spectrum sensing
perspective in cognitive radio networks is proposed and implemented using the realistic implementation
oriented model (R-model) with signal processing operations. The performance assessment of the different
sensing techniques in the existence of unknown or imprecisely known impulsive noise levels is done by
considering the signal detection in cognitive radio networks under a non-parametric multisensory detection
scenario. The examination focuses on performance comparison of basic spectrum sensing mechanisms as,
energy detection (ED) and cyclostationary feature detection (CSFD) along with the eigenvalue-based
detection methods namely, Maximum-minimum eigenvalue detection (MMED), Roy’s largest Root Test
(RLRT) which requires knowledge of the noise variance and Generalized Likelihood Ratio Test (GLRT)
which can be implemented as a test of the largest eigenvalues vs. Maximum-likelihood estimates a noise
variance. From simulation results it is observed that the detection performance of the GLRT method is
better than the other techniques in realistic implementation oriented model.
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
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.
ENERGY EFFICIENT COOPERATIVE SPECTRUM SENSING IN COGNITIVE RADIOIJCNCJournal
Sensing in cognitive radio (CR) protects the primary user (PU) from bad interference. Therefore, it is
assumed to be a requirement. However, sensing has two main challenges; first the CR is required to sense
the PU under very low signal to noise ratios which will take longer sensing time, and second, some CR
nodes may suffer from deep fading and shadowing effects. Cooperative spectrum sensing (CSS) is supposed
to solve these challenges. However, CSS adds extra energy consumption due to CRs send the sensing result
to the fusion center and receive the final decision from the fusion center. This is in addition to the sensing
energy itself. Therefore, CSS may consume considerable energy out of the battery of the CR node.
Therefore in this paper, we try to find jointly the sensing time required from each CR node and the number
of CR nodes who should perform sensing such that the energy and energy efficiency (i.e., ratio of
throughput to energy consumed) are optimized. Simulation results show that the joint optimization achieves
better in terms of energy efficiency than other approaches that perform separate optimization.
Localization of Objects using Stochastic TunnelingRana Basheer
A novel wireless localization scheme in the three dimensional domain that employs stochastic optimization with tunneling transformation to recursively estimate the location of wireless tags in a network from pair wise signal strength measurements. Spatially co-located wireless tags, receiving signals from a common transmitter, exhibit correlation in their Received Signal Strength Indicator (RSSI) values. Hence in a network of wireless tags, with pair wise correlation coefficients available, posterior distribution of the unknown tag separation is used to relatively localize them using maximum a posteriori (MAP) Estimator. However, due to the non-convex/non-tractable nature of this posterior distribution, deterministic optimization methods will end in one of the many local maxima unless the initial guess is close to the region of attraction of the global maximum. In this paper, a novel stochastic localization method called LOCalization Using Stochastic Tunneling (LOCUST) is proposed which utilizes constrained simulated annealing with tunneling transformation to solve this non-tractable posterior distribution. The tunneling transformation allows the optimization search operation to circumvent or “tunnel” through ill-shaped regions in the posterior distribution resulting in faster convergence to global maximum. Finally, simulation results of our localization method are presented
International Journal of Engineering and Science Invention (IJESI)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.
New optimization scheme for cooperative spectrum sensing taking different snr...eSAT Publishing House
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
Speech Enhancement Using Spectral Flatness Measure Based Spectral SubtractionIOSRJVSP
This paper is aimed to reduce background noise introduced in speech signal during capture, storage, transmission and processing using Spectral Subtraction algorithm. To consider the fact that colored noise corrupts the speech signal non-uniformly over different frequency bands, Multi-Band Spectral Subtraction (MBSS) approach is exploited wherein amount of noise subtracted from noisy speech signal is decided by a weighting factor. Choice of optimal values of weights decides the performance of the speech enhancement system. In this paper weights are decided based on SFM (Spectral Flatness Measure) than conventional SNR (Signal to Noise Ratio) based rule. Since SFM is able to provide true distinction between speech signal and noise signal. Spectrogram, Mean Opinion Score show that speech enhanced from proposed SFM based MBSS possess better perceptual quality and improved intelligibility than existing SNR based MBSS
Comparative performance analysis of channel normalization techniqueseSAT Journals
Abstract A major part of the interaction between humans takes place via speech communication. The speech signal carries both useful and unwanted information. Processing of such signals involve enhancing the useful information. The intelligibility of speech signals is significantly reduced due to the presence of unwanted information such as noise. Channel normalization algorithms suppress such additive noise introduced in the speech signals by transmission channel or by recording environment conditions. Enhancing the quality and intelligibility of speech signals improve the performance of speech systems such as Automatic speech recognition (ASR) , voice communication and hearing aids to name the few. Based on the experimental results the comparative analysis of channel normalization techniques have been presented in this paper to find out the most suitable algorithm for enhancing the speech signals. Keywords: Cepstral Mean Normalization, Spectral Subtraction, Weiner filter, Signal to Noise Ratio
International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Improvement of minimum tracking in Minimum Statistics noise estimation methodCSCJournals
Noise spectrum estimation is a fundamental component of speech enhancement and speech recognition systems. In this paper we propose a new method for minimum tracking in Minimum Statistics (MS) noise estimation method. This noise estimation algorithm is proposed for highly nonstationary noise environments. This was confirmed with formal listening tests which indicated that the proposed noise estimation algorithm when integrated in speech enhancement was preferred over other noise estimation algorithms.
Performance Evaluation of Adaptive Filters Structures for Acoustic Echo Cance...CSCJournals
We have designed and simulated an acoustic echo cancellation system for conferencing. This system is based upon a least-mean-square (LMS) adaptive algorithm and uses multi filter technique. A comparative study of both structure has been carried out and it is found that this new multi-filter converge faster than similar single long adaptive filter. Index Terms: LMS,Multiple sub filter ,Echo cancellation
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.
Reduction of Frequency offset Using Joint Clock for OFDM Based Cellular Syste...IJRST Journal
This project addresses the problem of clock synchronization between a base station (BS) and a mobile station (MS). A conventional technique for clock synchronization is that the MS clock is derived from the downlink signal originated from a base station. In cellular systems, a base station and mobile stations need to be synchronized before data exchange. Since the base station clock reference is more accurate, a mobile station typically derives its clock reference from the base station. But the carrier frequency offset due to Doppler shift may have harmful effects on the local clock derivation. This project proposes a joint clock and frequency synchronization technique between a base station and a mobile station, which is effective even with Doppler shift. We derive the joint estimation algorithm by analyzing the phase and the amplitude distortion caused by the sampling frequency offset and the carrier frequency offset. Simulation results showing the effectiveness of the proposed algorithm will also be presented.
Performance Analysis of Acoustic Echo Cancellation TechniquesIJERA Editor
Mainly, the adaptive filters are implemented in time domain which works efficiently in most of the applications. But in many applications the impulse response becomes too large, which increases the complexity of the adaptive filter beyond a level where it can no longer be implemented efficiently in time domain. An example of where this can happen would be acoustic echo cancellation (AEC) applications. So, there exists an alternative solution i.e. to implement the filters in frequency domain. AEC has so many applications in wide variety of problems in industrial operations, manufacturing and consumer products. Here in this paper, a comparative analysis of different acoustic echo cancellation techniques i.e. Frequency domain adaptive filter (FDAF), Least mean square (LMS), Normalized least mean square (NLMS) &Sign error (SE) is presented. The results are compared with different values of step sizes and the performance of these techniques is measured in terms of Error rate loss enhancement (ERLE), Mean square error (MSE)& Peak signal to noise ratio (PSNR).
Performance evaluation of different spectrum sensing techniques for realistic...ijwmn
In this paper, the performance assessment of five different detection techniques from spectrum sensing
perspective in cognitive radio networks is proposed and implemented using the realistic implementation
oriented model (R-model) with signal processing operations. The performance assessment of the different
sensing techniques in the existence of unknown or imprecisely known impulsive noise levels is done by
considering the signal detection in cognitive radio networks under a non-parametric multisensory detection
scenario. The examination focuses on performance comparison of basic spectrum sensing mechanisms as,
energy detection (ED) and cyclostationary feature detection (CSFD) along with the eigenvalue-based
detection methods namely, Maximum-minimum eigenvalue detection (MMED), Roy’s largest Root Test
(RLRT) which requires knowledge of the noise variance and Generalized Likelihood Ratio Test (GLRT)
which can be implemented as a test of the largest eigenvalues vs. Maximum-likelihood estimates a noise
variance. From simulation results it is observed that the detection performance of the GLRT method is
better than the other techniques in realistic implementation oriented model.
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
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.
ENERGY EFFICIENT COOPERATIVE SPECTRUM SENSING IN COGNITIVE RADIOIJCNCJournal
Sensing in cognitive radio (CR) protects the primary user (PU) from bad interference. Therefore, it is
assumed to be a requirement. However, sensing has two main challenges; first the CR is required to sense
the PU under very low signal to noise ratios which will take longer sensing time, and second, some CR
nodes may suffer from deep fading and shadowing effects. Cooperative spectrum sensing (CSS) is supposed
to solve these challenges. However, CSS adds extra energy consumption due to CRs send the sensing result
to the fusion center and receive the final decision from the fusion center. This is in addition to the sensing
energy itself. Therefore, CSS may consume considerable energy out of the battery of the CR node.
Therefore in this paper, we try to find jointly the sensing time required from each CR node and the number
of CR nodes who should perform sensing such that the energy and energy efficiency (i.e., ratio of
throughput to energy consumed) are optimized. Simulation results show that the joint optimization achieves
better in terms of energy efficiency than other approaches that perform separate optimization.
Localization of Objects using Stochastic TunnelingRana Basheer
A novel wireless localization scheme in the three dimensional domain that employs stochastic optimization with tunneling transformation to recursively estimate the location of wireless tags in a network from pair wise signal strength measurements. Spatially co-located wireless tags, receiving signals from a common transmitter, exhibit correlation in their Received Signal Strength Indicator (RSSI) values. Hence in a network of wireless tags, with pair wise correlation coefficients available, posterior distribution of the unknown tag separation is used to relatively localize them using maximum a posteriori (MAP) Estimator. However, due to the non-convex/non-tractable nature of this posterior distribution, deterministic optimization methods will end in one of the many local maxima unless the initial guess is close to the region of attraction of the global maximum. In this paper, a novel stochastic localization method called LOCalization Using Stochastic Tunneling (LOCUST) is proposed which utilizes constrained simulated annealing with tunneling transformation to solve this non-tractable posterior distribution. The tunneling transformation allows the optimization search operation to circumvent or “tunnel” through ill-shaped regions in the posterior distribution resulting in faster convergence to global maximum. Finally, simulation results of our localization method are presented
International Journal of Engineering and Science Invention (IJESI)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.
New optimization scheme for cooperative spectrum sensing taking different snr...eSAT Publishing House
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
Enhancement of New Channel Equalizer Using Adaptive Neuro Fuzzy Inference SystemIOSR Journals
Abstract: The rapidly increasing need for information communication requires higher speed data transmission over the existing channels. The data rate over these channels is limited mainly by Inter Symbol Interference (ISI). Channel equalizers are used to reduce the effect of ISI. In this paper, a new equalizer based on Adaptive Neuro-Fuzzy Inference System is presented. The performance of the proposed equalizer is evaluated for both linear as well as non-linear channels in terms of bit-error rate for different noise powers. Simulation results show that the proposed equalizer has better Bit Error Rate (BER) performance compared to multi-layer perceptron and least mean square equalizers. However, its BER performance is slightly poorer than that of radial basis function network and optimal Bayesian equalizer but is better in terms of structural complexity. Keywords: Channel equalizer, Hybrid learning algorithm, Intersymbol interference, Membership function, optimal Bayesian equalizer.
Enhancement of New Channel Equalizer Using Adaptive Neuro Fuzzy Inference SystemIOSR Journals
The rapidly increasing need for information communication requires higher speed data transmission over the existing channels. The data rate over these channels is limited mainly by Inter Symbol Interference (ISI). Channel equalizers are used to reduce the effect of ISI. In this paper, a new equalizer based on Adaptive Neuro-Fuzzy Inference System is presented. The performance of the proposed equalizer is evaluated for both linear as well as non-linear channels in terms of bit-error rate for different noise powers. Simulation results show that the proposed equalizer has better Bit Error Rate (BER) performance compared to multi-layer perceptron and least mean square equalizers. However, its BER performance is slightly poorer than that of radial basis function network and optimal Bayesian equalizer but is better in terms of structural complexity.
Performance analysis on the basis of a comparative study between multipath ra...ijmnct
Interference is the most important issue for present wireless communication. There are various kinds of
channel used in wireless communication. Here I want to show a performance analysis on the basis of two
different channels – AWGN and Multipath Rayleigh fading channel. This is the comparative analysis with
different kinds of modulation techniques. Here I have also measured the Bit Error Rate with respect to
different modulation techniques and compare the rate in different channels. My objective is to compare the
different characteristics of the transmitter and receiver for different types of channels and modulators.
Intersymbol interference caused by multipath in band limited frequency selective time dispersive channels distorts the transmitted signal, causing bit error at receiver. ISI is the major obstacle to high speed data transmission over wireless channels. Channel estimation is a technique used to combat the intersymbol interference. The objective of this paper is to improve channel estimation accuracy in MIMO-OFDM system by using modified variable step size leaky Least Mean Square (MVSSLLMS) algorithm proposed for MIMO OFDM System. So we are going to analyze Bit Error Rate for different signal to noise ratio, also compare the proposed scheme with standard LMS channel estimation method.
Adaptive Channel Equalization for Nonlinear Channels using Signed Regressor F...IDES Editor
Wireless communication systems are affected by
inter-symbol interference (ISI), co-channel interference in
the presence of additive white Gaussian noise. ISI is primarily
due to the distortion caused by frequency and time selectivity
of the fading channel and it causes performance degradation.
Equalization techniques are used to mitigate the effect of ISI
and noise for better demodulation. This paper presents a novel
technique for channel equalization. Here a Signed Regressor
adaptive algorithm based on FLANN (Functional Link Artificial
Neural Network) has been developed for nonlinear channel
equalization along with the analysis of MSE and BER. The
results are compared with the conventional adaptive LMS
algorithm based FLANN model. The Signed Regressor FLANN
shows better performance as compared to LMS based FLANN.
The equalizer presented shows considerable performance
compared to the other adaptive structure for both the linear
and non-linear models in terms of convergence rate, MSE
and BER over a wide range.
AREA EFFICIENT & COST EFFECTIVE PULSE SHAPING FILTER FOR SOFTWARE RADIOS ijasuc
In this paper area efficient and cost effective techniques for design of pulse shaping filter have been
presented to improve the computational and implementation complexity. Pulse shaping filters have been
designed and implemented by using Raised cosine filter, Nyquist filter and optimized half band filters for
software defined radio (SDR) based wireless applications. The performance of different filters is compared
in terms of BER and hardware requirements. The results show that the BER performance of the optimized
designs is almost identical to the Raised cosine filter with significant reduction in hardware requirements.
The hardware saving of 60% to 90% can be achieved by replacing the Raised cosine filter with proposed
filters to provide cost effective solution for wireless communication applications.
Comparative Analysis of Different Wavelet Functions using Modified Adaptive F...IJERA Editor
The traditional method of wavelet denoising is inefficient in removing the overlap noise between noisy signal
and noise, due to which a modified adaptive filtering based on wavelet transform method is introduced. The
method used in this paper filters out the noise on the basis of wavelet denoising using different wavelet
functions. The simulation results indicate the Signal to Noise ratio (SNR), Mean Square Error (MSE) and signal
error power spectral density comparison plot between different wavelet functions. These comparison results
verified that Daubechies is more efficient than other wavelet functions in filtering out noise in all perspectives.
IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
Call for paper 2012, hard copy of Certificate, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJCER, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, research and review articles, IJCER Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathematics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer review journal, indexed journal, research and review articles, engineering journal, www.ijceronline.com, research journals,
yahoo journals, bing journals, International Journal of Computational Engineering Research, Google journals, hard copy of Certificate,
journal of engineering, online Submission
Classical Discrete-Time Fourier TransformBased Channel Estimation for MIMO-OF...IJCSEA Journal
In this document, we look at various time domain channel estimation methods with this constraint of null carriers at spectrumborders.We showin detail howto gauge the importance of the “border effect” depending on the number of null carriers, which may vary from one system to another. Thereby we assess the limit of the technique discussed when the number of null carriers is large. Finally the DFT with the truncated singular value decomposition (SVD) technique is proposed to completely eliminate the impact of the null subcarriers whatever their number. A technique for the determination of the truncation threshold for any MIMO-OFDM system is also proposed.
DESIGN REALIZATION AND PERFORMANCE EVALUATION OF AN ACOUSTIC ECHO CANCELLATIO...sipij
Nowadays, in the field of communications, AEC (acoustic echo cancellation) is truly essential with respect
to the quality of multimedia transmission. In this paper, we designed and developed an efficient AEC based
on adaptive filters to improve quality of service in telecommunications against the phenomena of acoustic
echo, which is indeed a problem in hands-free communications.The main advantage of the proposed algorithm is its capacity of tracking non-stationary signals such as acoustic echo. In this work the acoustic echo cancellation (AEC) is modeled using a digital signal
processing technique especially Simulink Blocksets. The algorithm’s code is generated in Matlab Simulink
programming environment. At simulation level, results of simulink implementation prove that module
behavior is realistic when it comes to cancellation of echo in hands free communication using adaptive algorithm.Results obtained with our algorithm in terms of ERLE criteria are confronted to IUT-T recommendation
G.168.
This topic will cover the listed topics below regarding linear equalization and its variations:
Fundamental of equalization
Equalizer
Categories of equalization
Depending on the time nature
Structure of adaptive equalization
Classification of equalizer
Linear equalizer
Transversal equalizer
Lattice equalizer
Advantage and disadvantages of lattice
Disadvantages of linear equalizer
Equalization, diversity, and channel coding are three techniques which can be used independently or in tandem to improve received signal quality.
Equalization compensates for intersymbol interference (ISI) created by multipath within time dispersive channels.
If the modulation bandwidth exceeds the coherence bandwidth of the radio channel, ISI occurs and modulation pulses are spread in time.
An equalizer within a receiver compensates for the average range of expected channel amplitude and delay characteristics.
Equalizers must be adaptive since the channel is generally unknown and time varying.
Design Analysis and Simulation of 25 TAP FIR Raised Cosine Filter IJEEE
Pulse shaping filter plays an important in multirate signal processing for Software Defined Radio based wireless and mobile applications. In this paper Raised Cosine filter has been presented for pulse shaping using Kaiser and Gaussian window techniques. The raised cosine filter introduces group delay that causes ISI in wireless communication. The ISI due to group delay can be removed by delaying the input signal to the filter. The ISI can also be rejected by reduced roll off factor α which results in narrow transition width. The proposed filter has been designed and simulated using Matlab. The simulated results show that the performance of both window techniques are almost same but Gaussian window based pulse shaping filter provides improved stop band attenuation is better as compared to Kaiser window technique.
Effects of filtering on ber performance of an ofdm systemeSAT Journals
Abstract In upcoming generations, wireless communication system requires a higher standard in order to provide high quality of services to customers. Orthogonal Frequency Division Multiplexing (OFDM) is an efficient modulation technique of forthcoming wireless systems which can be implemented easily. In this paper, an effort has been made to analyze how well an OFDM system can perform when a signal is transmitted over an Additive White Gaussian Noise (AWGN) channel using 16 QAM modulation techniques. The performance of OFDM system with pulse shaping filters are also evaluated and results reveal that the pulse shaped OFDM improve the overall performance of the system in terms of BER. We use Different pulse shaping filters such asRaised cosine, FIR Nyquist and SQRT Raised Cosine for analyzingthe Bit Error Rate (BER) performance. Index Terms: AWGN, ICI, OFDM, Bit Error Rate.
Analysis and Estimation of Harmonics Using Wavelet TechniqueRadita Apriana
The paper develops an approach based on wavelet technique for the evaluation and estimation of
harmonic contents of power system waveform. The proposed algorithm decomposes the signal waveforms
into the uniform frequency sub-bands corresponding to the odd harmonic components of the signal. The
proposed implementation of algorithm determines the frequency bands of harmonics which retain both the
time and frequency relationship of the original waveforms and uses a method to suppress those
harmonics.Thewaveletalgorithm is selected to obtain compatible output bands with the harmonic groups
defined in the standards for power-supply systems. A comparative analysis will be done with the input and
the results obtained from the wavelet transform (WT) for different measuring conditions and Simulation
results are given.
Comparative Analysis of Dispersion Compensating Fiber (DCF) and Multiple Opti...rahulmonikasharma
Optical communication when used for long haul communication is characterized by dispersion and nonlinearities. Different techniques are used for the dispersion compensation and nonlinearity mitigation. Two of these techniques are Dispersion Compensating Fiber (DCF) and Optical Phase Conjugation (OPC). In this paper the performance of the system is analyzed by comparing various results at the receiver. A 10Gb/s NRZ signal is launched into a long Single Mode Fiber (SMF). Results in the terms of Q-factor (linear) and BER are observed by varying fiber length. Optical system consisting of one OPC and two OPC is also analyzed for different transmission distance. Simulation results show that, when compared with optical system consisting of one OPC, Q-factor improvement of 3.51 is achieved for the optical system consisting of two OPC. Nonlinearities are mitigated using DCF and OPC and on comparing with DCF, Q-factor improvement of 11.3 is achieved for OPC.
1. International Journal of Research in Advent Technology, Vol.2, No.5, May 2014
E-ISSN: 2321-9637
Performance Enhancement of Optical Communication
329
Using Decision Feedback Equalization
Amit kaushik1, Hemant Dalal 2
Department of Electronics and Communication1,2
CBS Group of Institutions1,2
Jhajjar, Haryana
Email id-kaushik_amit87@yahoo.com, hemantdalal87@gmail.com
Abstract : This paper, proposes an adaptive equalizer by integrating the fractional spaced equalizer (FSE) with decision
feedback equalizer (DFE) for optical channel to compensate the problem of pulse dispersion effect in optical link. The
performance of the equalizer is improved by adopting the activity detection guidance (ADG) with tap decoupling (TD) in
the fractional spaced decision feedback equalizer (FSDFE) to get fruitful outcomes. In this paper a fractionally spaced
decision feedback equalization (FSDFE) structure which replaces the symbol spaced feedback filter with a fractionally
spaced feedback filter is used to improve the stability and the steady-state error performance and the convergence rate.
As the impulse response of a typical optical link would have regions that are essentially zero, the employment of the
activity detection scheme with Tap Decoupling would further enhance the steady-state error performance and
convergence rate. The simulation results revealed that: the FSDFE with ADG and TD offers a superior performance than
its counterpart without ADG and TD. Where, it offers improvement in the effectiveness of amplitude distortion.
Index : ADFE, ADG, DFE, FSE, FSDFE, I.S.I and TD
I. INTRODUCTION
In Long haul optical communications usually there are
several keys area to ensure the data transfer is error-free.
These areas include modulation method, type of
amplifier used, and the error correction scheme and
dispersion compensation. In optical communications,
high-speed data transfer is limited by signal distortion,
caused by the broadening of pulses that result in
Intersymbol Interference (ISI).
There are several forms of dispersion, such as:
Intermodal dispersion that occurs only in multimode
fiber due to different velocities for different modes and
hence, it reduces the performance of optical network at
higher data rates. The second one is intra-modal
dispersion which occurs in all types of fibers. Intra-modal
dispersion occurs because different colors of
light travel through different materials and different
waveguide structures at different speeds. Intra modal
dispersion is also called as chromatic dispersion (CD)
which can be divided into two parts: the first one, is
called material dispersion that limits the fiber
bandwidth or the information-carrying capacity of the
fiber and also limits the transmission distance, since the
shorter the pulses, the more susceptible they are to lSI.
The second type is the waveguide dispersion occurs
because the single-mode fiber only confines about 80
percent of the optical power to the core. Thus dispersion
arises due to light propagating in the cladding travels
faster than the light confined to the core. So, dispersion
occurs because light propagates differently in the core
than in the cladding. The intra modal dispersion can be
expressed mathematically by
Dintramodal = Dm+ DWG
where: D M is the material dispersion,
DWG is the waveguide dispersion.
The numerous techniques in adaptive equalization and
equalizer are used that gives suitable and effective
equalization approach for a typical optical channel. In
this paper we evaluate the causes of dispersion in a
typical optical link and its limiting effects to the
possible communication capacity, then to reverse the
effects that the channel has on the transmitted signal
and reproduce the original signal at the received end.
Finally, design an adaptive equalizer to mitigate the
pulse dispersion effects of an optical link. A range of
adaptive algorithms and equalizer structures are
evaluated. The Least Mean Square (LMS) algorithm is
chosen for its robustness and computational simplicity.
II. ADAPTIVE EQUALIZER
Linear equalizer is not allways useful for high data bit
rate with a dispersive optical channel suffers from lSI or
amplitude distortion and used where, the channel does
not suffer from amplitude distortion. On the other hand,
non-linear equalizer approved its capability to provide
superior performance in amplitude distorted channel
and will be very beneficial and relevant to the
application in optical communications.
The adaptive equalizer is exploited to compensate the
dispersion in optical channel, it allows for long haul
communication before requiring a repeater, the benefits
are to save infrastructure and equipment cost for optical
2. International Journal of Research in Advent Technology, Vol.2, No.5, May 2014
E-ISSN: 2321-9637
, must be above a
330
communication link [1]. It is defined as the equalizer
which adjusts to different environments and involves a
process of filtering input signal to match a desired
response. Its parameters are automatically updated by
making a set of measurements of the underlying signals
and applying that set to the adaptive filtering algorithm
such that the difference between the output and the
desired response is minimized in either a statistical or
deterministic sense [2]. Concerning the adaptive
algorithms, we have several numbers of adaptive
algorithms, The most important of them are the least
mean squares (LMS) error algorithm and recursive least
squares (RLS) algorithm. The criterion used in the
adaptive LMS algorithm is the minimization of the
mean square error (MSE) between the desired equalizer
output and the actual equalizer output in [1 0] for the N-taps
adaptive transversal filter and the output is given
by:
y(n)=Σ
3. −
where: x(n-i) is the filter input, wi(n) is the tap weight.
Fractionally Spaced Equalizer (FSE) is based on
sampling the incoming signal at least as fast as the
Nyquist rate. Such equalizers have taps that are spaced
closer than conventional adaptive equalizers, and with a
sufficient number of taps, it is almost independent of
the channel delay distortion. It means that the equalizer
can negate the channel distortion without enhancing the
noise [3]. Given the above properties, the FSE
technique is a highly desirable application since it
minimizes noise enhancement. With appropriately
chosen tap spacing; the FSE can be configured as the
excellent feed forward filter. The combination of DFE
with FSE technique, provides minimize noise
enhancement and Excellent amplitude distortion
performance.
Decision Feedback Equalizer
Decision Feedback Equalizer have both the feed
forward and feedback filters are essentially linear
filters. It is a non-linear structure because of the non-linear
operation in the feedback loop (decision
threshold); its current output is based on the output of
previous symbols. The decision feedback equalizer has
zero noise enhancements in the feedback loop. The
above DFE structure has N
1
+ N
2
+ 1 feed forward taps
and
N
3
feedback taps [2].
The output of the equalizer is given by:
^=Σ ∗
Σ
where is the tap gain and y x n c
n
is the input for the
forward filter,is the tap gain for the feed back filter and
dFi x (ik) is the previous decision made on the
detected signal [4].
Activity Detection Guidance
Activity detection guidance technique is a method of
detecting active taps in a communication channel,
implementing such technique capable of detecting
active taps in the channel, non-active taps can be
excluded in the estimation of the channel response. This
gives a better convergence rate and asymptotic
performance. The detection of the ‘active’ taps of a
time-invariant channel is governed by the equation [6].
, =
Σ . !
#
Σ #
!
Where, i is time index, k is tap index, C
k
is known as
the activity measure and N is the number of input
samples. In order to determine a tap to be active, the
value of the activity measure, C
k
certain threshold. The activity threshold is given by:
$%, '
(). log
Modifications to the activity measure have to be made
to reduce the tap coupling effect [6].
$$
=Σ [ ./0! !.1 !]
Σ 1 !
#
III. Analysis of Impulse Response in Optical
Channel
The frequency response of the base band is given by
H(f)=345 678
678 9 :
: 7;8;
And the impulse response of a typical optical channel
represented by a cosine-squared pulse shape and is
given by:
h(t) ==
;
8
8 , 8
?cos26@
;A@A8
;
BCDBEFBGB
IV. SIMULATION RESULTS AND
DISCUSSIONS
It is clear that the simulated impulse response is
resembling a cosine-square shape and having a total of
7-taps. The feed forward section has a total of 6-taps,
the fIrst tap has a magnitude of I and the fourth tap has
a magnitude of 0.8. The rest of the taps are in active or
zero except for tap 7, which is the feedback tap with a
magnitude of 1 . On the other hand, for the estimated
channel impulse response we have run the equalizer for
30000 sample inputs in order to achieve an impulse
response in close proximity to the actual simulated
4. International Journal of Research in Advent Technology, Vol.2, No.5, May 2014
E-ISSN: 2321-9637
331
channel. It is clear that the channel bears a fair
resemblance of the simulated channel. But, the inactive
taps, which were supposed to be zero, were not flat.
This is due to the noisy estimates of the inactive taps in
the channel.
Fig. 1: Impulse response with FSDFE after simulation
Fig. 2: Estimated channel impulse response for FSDF
Fig. 3: Asymptotic perfornance for FSDF
Fig. 4: Active taps count for FSDFE.
Fig. 5: Squared difference of input to channel and
output of equalizer for FSDFE.
FSDFE with ADG and Tap Decoupling.
We have noticed that the inactive taps in the estimated
channel were not estimated at zero Adopting ADG with
FSDFE could improve the convergence rate and
asymptotic performance, detect the non active taps,
disregard them in the calculation of the tap weight
adoption and set them to zero [5]. However, the true
number of active taps cannot be detected accurately and
the inactive taps will still suffer from the noisy
estimates that are common in any communication
channel. The inability to detect the true number of
active taps accurately is due to the correlation within
the input signal that is causing the coupling amongst the
output of the unknown channel taps.
5. International Journal of Research in Advent Technology, Vol.2, No.5, May 2014
E-ISSN: 2321-9637
332
Fig. 6: Simulated channel impulse response.
Fig. 7: Estimated channel impulse response.
Fig.8: Asymptotic performance of the equalizer.
Fig.9: Active taps count.
Fig.10: Output of equalizer
V. CONCLUSION
With the successful development of the adaptive
modified Decision Feedback Equalizer with activity
detection guidance and tap decoupling, it offers an
excellent alternative to the existing equalization
techniques available in the optical communication is
implemented using the Least Mean Square (LMS)
technique, using stochastic gradient adaptation, led to a
faster convergence rate, as only the active taps need to
be adapted, and better asymptotic performance as
shown clearly.
REFERENCES
[1] Theodore S. Rappaport, “Wireless Communications
– Principles and Practice” 2
nd
edition, Prentice Hall
Communications Engineering and Emerging
Technologies Series, Upper Saddle River, New
Jersey, 2002.
[2] B.L.Kaspers, “Equalization of Multimode Optical
Fiber Systems”, Bell System Technical Journal,
September 1982.
6. International Journal of Research in Advent Technology, Vol.2, No.5, May 2014
E-ISSN: 2321-9637
333
[3] John M. Senior, Optical Fiber Communications -
Principles and Practice 2nd edition, Prentice Hall
International Series in Optoelectronics, New York, 1
992.
[4]S.D. Personick, Time dispersion in dielectric
waveguides, Bell Syst. Tech. J., 50(3), pp. 843-859,
1 971 .
[5] Simon Haykin, Adaptive filter theory, Prentice-
Hall, Upper Saddle River, N.J, 1 996
[6] John Homer, Iven Mareels, Robert R. Bitmead, Bo
Wahlberg and Fredrik Gustafsson, “LMS Estimation
via Structural Detection”, IEEE Transactions on
signal processing, Vol. 46, No. 10, October 1998.