Download or read book Phase Noise Compensation for Long haul Coherent Optical Communication Systems Using OFDM written by Jingwen Zhu and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Long-haul optical transmission systems employing coherent optical orthogonal frequency division multiplexing (CO-OFDM) are sensitive to laser phase noise. This causes a common phase rotation and inter-carrier interference. An effective method to compensate for the phase noise is to insert an RF-pilot tone in the middle of the OFDM signal. This RF-pilot is used to reverse the phase distortion at the receiver. This thesis presents a detailed performance analysis of the RF-pilot phase noise compensation scheme in a simulated 64 Gbit/s CO-OFDM system. The effects of various parameters including laser linewidth, Mach-Zehnder modulator drive power, pilot-tosignal ratio, and fiber launch power are investigated. A comparison with the pilot-aided common phase error compensation method is provided to show the differences in the BER performance with respect to the required overhead.
Download or read book Adaptive Channel Equalization Using Radial Basis Function Networks and MLP written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the major practical problems in digital communication systems is channel distortion which causes errors due to intersymbol interference. Since the source signal is in general broadband, the various frequency components experience different steady state amplitude and phase changes as they pass through the channel, causing distortion in the received message. This distortion translates into errors in the received sequence. Our problem as communication engineers is to restore the transmitted sequence or, equivalently, to identify the inverse of the channel, given the observed sequence at the channel output. This task is accomplished by adaptive equalizers. Typically, adaptive equalizers used in digital communications require an initial training period, during which a known data sequence is transmitted. A replica of this sequence is made available at the receiver in proper synchronism with the transmitter, thereby making it possible for adjustments to be made to the equalizer coefficients in accordance with the adaptive filtering algorithm employed in the equalizer design. When the training is completed, the equalizer is switched to its decision directed mode. Decision feedback equalizers are used extensively in practical communication systems. They are more powerful than linear equalizers especially for severe inter-symbol interference (ISI) channels without as much noise enhancement as the linear equalizers. This thesis addresses the problem of adaptive channel equalization in environments where the interfering noise exhibits Gaussian behavior. In this thesis, radial basis function (RBF) network is used to implement DFE. Advantages and problems of this system are discussed and its results are then compared with DFE using multi layer perceptron net (MLP). Results indicate that the implemented system outperforms both the least-mean square(LMS) algorithm and MLP, given the same signal-to-noise ratio as it offers minimum mean square error. The learning rate of the im.
Download or read book Adaptive Decision Feedback Equalization With Continuous time Infinite Impulse Response Filters written by Shayan Shahramian and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In high-speed (10+Gb/s) chip-to-chip links, the primary impairments to signal integrity are noise, crosstalk, and a smooth tail in the pulse response resulting in inter-symbol interference (ISI) sometimes spanning more than 10 unit intervals (UIs). Although often simple in their implementation, continuous time linear equalizers amplify high-frequency noise and crosstalk and consume extra power. A conventional discrete-time (DT) decision feedback equalizer (DFE) is well-suited and power efficient for channels with a few dominant post-cursor ISI terms, however, the power can become prohibitive for channels with many post-cursor ISI terms. Infinite impulse response (IIR) DFEs can equalize post-cursor ISI persisting 10 or more UIs while consuming low-power comparable to just one DT tap. DFE architectures with varying numbers of DT and IIR taps are compared for use in typical wireline channels, and it is found that 2 IIR taps can offer an excellent compromise between power consumption and performance. However, an IIR DFEâ s performance degrades significantly as the feedback loop delay increases. Fortunately, adding a single DT tap can eliminate the degradation. The first ever hybrid DFE combining 1 DT and multiple (2) IIR taps is presented equalizing 24dB loss at half the bitrate while consuming 4.1mW at 10Gb/s. A novel edge based adaptation algorithm is also presented for DT DFEs which converges faster than previous algorithms while using the same high-speed circuitry and signals required for clock recovery. The edge based algorithm is extended to work for a 1 DT + 1 IIR DFE. The 1 DT + 1 IIR DFE along with integrated clock recovery and adaptation is demonstrated in 28nm FD-SOI CMOS. At 16Gb/s with a 30dB-loss channel, a BER below 10â 12 is measured over a 0.3UI timing window. The novel edge-based algorithm adapts both IIR and discrete-tap equalizer coefficients using the same high-speed circuitry and signals required for clock recovery. The adaptive DFE converges within 5us and is robust in the presence of poorly-conditioned data.
Download or read book A Class of Batch iterative Methods for the Equalization of Intersymbol Interference Channels written by Albert Michael Chan and published by . This book was released on 1999 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 2240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum Mechanical Interference Between Optical Transitions The Effect of Laser Intensity Noise written by and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a previous publication Phys. Rev. A 55, 552 (1997), we considered the effect of laser phase fluctuations on three-photon-one-photon phase control of resonance-enhanced photoionization. Here we extend those studies by considering the role of laser intensity noise in addition to laser phase noise. While our results indicate that relative intensity fluctuations between the fundamental field and its third harmonic have a significant effect on control, the contrast between constructive and destructive interference is nonetheless two orders of magnitude, even under (reasonable) worst case situations. Consequently, neither laser intensity nor phase fluctuations appear to pose a serious impediment to the efficient phase control of atomic and molecular processes.
Download or read book Nonlinear Electrical Compensation for the Coherent Optical OFDM System written by Jie Pan and published by . This book was released on 2010 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: One major drawback of a Coherent-Optical Orthogonal Frequency Division Multiplexing (CO-OFDM) system is its sensitivity to fiber nonlinearity. It has been shown that a Volterra series based nonlinear equalizer can compensate distortion introduced by the fiber nonlinearity. One major disadvantage of Volterra series is its complexity which can be reduced by removing its "unimportant" coefficients. The resulting Volterra system is called the sparse Volterra system. The Wiener-Hammerstein model is another popular nonlinear signal processing technique with a simpler structure. In this thesis, the nonlinear distortion of a CO-OFDM system is investigated, and equalizers based on Volterra model, sparse Volterra model and Wiener-Hammerstein model are designed. This is the first attempt to apply the Wiener-Hammerstein model to compensate nonlinear distortion in optical communication systems. A comparison between predistorters and equalizers is also presented. To the best of author's knowledge, no such a study has ever been conducted for optical communication systems.
Download or read book A Novel Method for the Suppression of Servo induced Laser Phase Noise written by Philipp Herbig and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Evaluation of Adaptive Equalizer in a Communication System written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This project deals with the study of the various kinds of interferences in a communication channel viz. Inter symbol Interference, Multipath Interference and Additive Interference. It deals with the design of an Adaptive Equalizer. The idea of the equalizer is to build (another) filter in the receiver that counteracts the effect of the channel. In essence, the equalizer must "unscatter" the impulse response. This can be stated as the goal of designing the equalizer E so that the impulse response of the combined channel and equalizer CE has a single spike. This can be solved using different techniques. In this project, we have implemented an 'Adaptive Equalizer' using four different algorithms in Matlab. We have suggested different ways to decide the coefficients of the equalizer. The first procedure (LEAST SQUARE ALGORITHM) minimizes the square of the symbol recovery error over a block of data which can be done by using matrix pseudo inversion. The second method (LEAST MEAN SQUARE ALGORITHM) involves minimizing the square of the error between the received data values and the transmitted values which are achieved via an adaptive element. The third method (DECISION DIRECTED ALGORITHM) and the fourth method (DISPERSION MINIMIZING ALGORITHM) are used when there is no training sequence and other performance functions are appropriate. In addition to this we have undertaken a study and realization of the Bit Error Rate of a communication system using VisSim Software.
Download or read book OFDM for Optical Communications written by William Shieh and published by Academic Press. This book was released on 2009-09-18 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book on optical OFDM by the leading pioneers in the field The only book to cover error correction codes for optical OFDM Gives applications of OFDM to free-space communications, optical access networks, and metro and log haul transports show optical OFDM can be implemented Contains introductions to signal processing for optical engineers and optical communication fundamentals for wireless engineers This book gives a coherent and comprehensive introduction to the fundamentals of OFDM signal processing, with a distinctive focus on its broad range of applications. It evaluates the architecture, design and performance of a number of OFDM variations, discusses coded OFDM, and gives a detailed study of error correction codes for access networks, 100 Gb/s Ethernet and future optical networks. The emerging applications of optical OFDM, including single-mode fiber transmission, multimode fiber transmission, free space optical systems, and optical access networks are examined, with particular attention paid to passive optical networks, radio-over-fiber, WiMAX and UWB communications. Written by two of the leading contributors to the field, this book will be a unique reference for optical communications engineers and scientists. Students, technical managers and telecom executives seeking to understand this new technology for future-generation optical networks will find the book invaluable. William Shieh is an associate professor and reader in the electrical and electronic engineering department, The University of Melbourne, Australia. He received his M.S. degree in electrical engineering and Ph.D. degree in physics both from University of Southern California. Ivan Djordjevic is an Assistant Professor of Electrical and Computer Engineering at the University of Arizona, Tucson, where he directs the Optical Communications Systems Laboratory (OCSL). His current research interests include optical networks, error control coding, constrained coding, coded modulation, turbo equalization, OFDM applications, and quantum error correction. "This wonderful book is the first one to address the rapidly emerging optical OFDM field. Written by two leading researchers in the field, the book is structured to comprehensively cover any optical OFDM aspect one could possibly think of, from the most fundamental to the most specialized. The book adopts a coherent line of presentation, while striking a thoughtful balance between the various topics, gradually developing the optical-physics and communication-theoretic concepts required for deep comprehension of the topic, eventually treating the multiple optical OFDM methods, variations and applications. In my view this book will remain relevant for many years to come, and will be increasingly accessed by graduate students, accomplished researchers as well as telecommunication engineers and managers keen to attain a perspective on the emerging role of OFDM in the evolution of photonic networks." -- Prof. Moshe Nazarathy, EE Dept., Technion, Israel Institute of Technology The first book on optical OFDM by the leading pioneers in the field The only book to cover error correction codes for optical OFDM Applications of OFDM to free-space communications, optical access networks, and metro and log haul transports show optical OFDM can be implemented An introduction to signal processing for optical communications An introduction to optical communication fundamentals for the wireless engineer
Download or read book Bit Interleaved Coded Modulation written by Albert Guillén i Fàbregas and published by Now Publishers Inc. This book was released on 2008 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bit-Interleaved Coded Modulation is a comprehensive study of the subject, providing a comprehensive review of one of the most important coding schemes in modern communication systems.
Download or read book Noise and Signal Interference in Optical Fiber Transmission Systems written by Stefano Bottacchi and published by John Wiley & Sons. This book was released on 2008-11-20 with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive reference to noise and signal interference in optical fiber communications Noise and Signal Interference in Optical Fiber Transmission Systems is a compendium on specific topics within optical fiber transmission and the optimization process of the system design. It offers comprehensive treatment of noise and intersymbol interference (ISI) components affecting optical fiber communications systems, containing coverage on noise from the light source, the fiber and the receiver. The ISI is modeled with a statistical approach, leading to new useful computational methods. The author discusses the subject with the help of numerous applications and simulations of noise and signal interference theory. Key features: Complete all-in-one reference on the subject for engineers and designers of optical fiber transmission systems Discusses the physical principles behind several noise contributions encountered in the optical communications systems design, including contributions from the light source, the fiber and the receiver Covers the theory of the ISI for the binary signal, as well as noise statistics Discusses the theory and the mathematical models of the numerous noise components (such as optical noise, photodetection noise and reflection noise) Introduces the frequency description of the ISI and provides new calculation methods based on the characteristic functions Provides useful tools and examples for optimum design of optical fiber transmission networks and systems This book will serve as a comprehensive reference for researchers, R & D engineers, developers and designers working on optical transmission systems and optical communications. Advanced students in optical communications and related fields will also find this book useful.
Download or read book Optical Fiber Telecommunications VB written by Ivan Kaminow and published by Elsevier. This book was released on 2010-07-28 with total page 929 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Fiber Telecommunications V (A&B) is the fifth in a series that has chronicled the progress in the research and development of lightwave communications since the early 1970s. Written by active authorities from academia and industry, this edition not only brings a fresh look to many essential topics but also focuses on network management and services. Using high bandwidth in a cost-effective manner for the development of customer applications is a central theme. This book is ideal for R&D engineers and managers, optical systems implementers, university researchers and students, network operators, and the investment community. Volume (A) is devoted to components and subsystems, including: semiconductor lasers, modulators, photodetectors, integrated photonic circuits, photonic crystals, specialty fibers, polarization-mode dispersion, electronic signal processing, MEMS, nonlinear optical signal processing, and quantum information technologies. Volume (B) is devoted to systems and networks, including: advanced modulation formats, coherent systems, time-multiplexed systems, performance monitoring, reconfigurable add-drop multiplexers, Ethernet technologies, broadband access and services, metro networks, long-haul transmission, optical switching, microwave photonics, computer interconnections, and simulation tools. Biographical Sketches Ivan Kaminow retired from Bell Labs in 1996 after a 42-year career. He conducted seminal studies on electrooptic modulators and materials, Raman scattering in ferroelectrics, integrated optics, semiconductor lasers (DBR , ridge-waveguide InGaAsP and multi-frequency), birefringent optical fibers, and WDM networks. Later, he led research on WDM components (EDFAs, AWGs and fiber Fabry-Perot Filters), and on WDM local and wide area networks. He is a member of the National Academy of Engineering and a recipient of the IEEE/OSA John Tyndall, OSA Charles Townes and IEEE/LEOS Quantum Electronics Awards. Since 2004, he has been Adjunct Professor of Electrical Engineering at the University of California, Berkeley. Tingye Li retired from AT&T in 1998 after a 41-year career at Bell Labs and AT&T Labs. His seminal work on laser resonator modes is considered a classic. Since the late 1960s, He and his groups have conducted pioneering studies on lightwave technologies and systems. He led the work on amplified WDM transmission systems and championed their deployment for upgrading network capacity. He is a member of the National Academy of Engineering and a foreign member of the Chinese Academy of Engineering. He is a recipient of the IEEE David Sarnoff Award, IEEE/OSA John Tyndall Award, OSA Ives Medal/Quinn Endowment, AT&T Science and Technology Medal, and IEEE Photonics Award. Alan Willner has worked at AT&T Bell Labs and Bellcore, and he is Professor of Electrical Engineering at the University of Southern California. He received the NSF Presidential Faculty Fellows Award from the White House, Packard Foundation Fellowship, NSF National Young Investigator Award, Fulbright Foundation Senior Scholar, IEEE LEOS Distinguished Lecturer, and USC University-Wide Award for Excellence in Teaching. He is a Fellow of IEEE and OSA, and he has been President of the IEEE LEOS, Editor-in-Chief of the IEEE/OSA J. of Lightwave Technology, Editor-in-Chief of Optics Letters, Co-Chair of the OSA Science & Engineering Council, and General Co-Chair of the Conference on Lasers and Electro-Optics. For nearly three decades, the OFT series has served as the comprehensive primary resource covering progress in the science and technology of optical fiber telecom. It has been essential for the bookshelves of scientists and engineers active in the field. OFT V provides updates on considerable progress in established disciplines, as well as introductions to new topics. [OFT V]... generates a value that is even higher than that of the sum of its chapters.
Download or read book OFDM Systems for Wireless Communications written by Adarsh Narasimhamurthy and published by Springer Nature. This book was released on 2022-06-01 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) systems are widely used in the standards for digital audio/video broadcasting, WiFi and WiMax. Being a frequency-domain approach to communications, OFDM has important advantages in dealing with the frequency-selective nature of high data rate wireless communication channels. As the needs for operating with higher data rates become more pressing, OFDM systems have emerged as an effective physical-layer solution. This short monograph is intended as a tutorial which highlights the deleterious aspects of the wireless channel and presents why OFDM is a good choice as a modulation that can transmit at high data rates. The system-level approach we shall pursue will also point out the disadvantages of OFDM systems especially in the context of peak to average ratio, and carrier frequency synchronization. Finally, simulation of OFDM systems will be given due prominence. Simple MATLAB programs are provided for bit error rate simulation using a discrete-time OFDM representation. Software is also provided to simulate the effects of inter-block-interference, inter-carrier-interference and signal clipping on the error rate performance. Different components of the OFDM system are described, and detailed implementation notes are provided for the programs. The program can be downloaded here. Table of Contents: Introduction / Modeling Wireless Channels / Baseband OFDM System / Carrier Frequency Offset / Peak to Average Power Ratio / Simulation of the Performance of OFDM Systems / Conclusions
Download or read book Fiber Optic Measurement Techniques written by Rongqing Hui and published by Academic Press. This book was released on 2022-11-18 with total page 846 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fiber Optic Measurement Techniques is an indispensable collection of key optical measurement techniques essential for developing and characterizing today’s photonic devices and fiber optic systems. The book gives comprehensive and systematic descriptions of various fiber optic measurement methods with the emphasis on the understanding of optoelectronic signal processing methodologies, helping the reader to weigh up the pros and cons of each technique and establish their suitability for the task at hand. Carefully balancing descriptions of principle, operations and optoelectronic circuit implementation, this indispensable resource will enable the engineer to: Understand the implications of various measurement results and system performance qualifications Characterize modern optical systems and devices Select optical devices and subsystems in optical network design and implementation Design innovative instrumentations for fiber optic systems The 2nd edition of this successful reference has been extensively updated (with 150 new pages) to reflect the advances in the field since publication in 2008 and includes: A new chapter on fiber-based optical sensors and spectroscopy techniques A new chapter on measurement uncertainty and error analysis Fiber Optic Measurement Techniques brings together in one volume the fundamental principles with the latest techniques, making it a complete resource for the optical and communications engineer developing future optical devices and fiber optic systems. The only book to combine explanations of the basic principles with latest techniques to enable the engineer to develop photonic systems of the future Careful and systematic presentation of measurement methods to help engineers to choose the most appropriate for their application The latest methods covered, such as real-time optical monitoring and phase coded systems and subsystems, making this the most up-to-date guide to fiber optic measurement
Download or read book Springer Handbook of Optical Networks written by Biswanath Mukherjee and published by Springer Nature. This book was released on 2020-10-15 with total page 1169 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook is an authoritative, comprehensive reference on optical networks, the backbone of today’s communication and information society. The book reviews the many underlying technologies that enable the global optical communications infrastructure, but also explains current research trends targeted towards continued capacity scaling and enhanced networking flexibility in support of an unabated traffic growth fueled by ever-emerging new applications. The book is divided into four parts: Optical Subsystems for Transmission and Switching, Core Networks, Datacenter and Super-Computer Networking, and Optical Access and Wireless Networks. Each chapter is written by world-renown experts that represent academia, industry, and international government and regulatory agencies. Every chapter provides a complete picture of its field, from entry-level information to a snapshot of the respective state-of-the-art technologies to emerging research trends, providing something useful for the novice who wants to get familiar with the field to the expert who wants to get a concise view of future trends.
