Download or read book Design and Analysis of Adaptively Modulated Optical Orthogonal Frequency Division Multiple Access Multiband Passive Optical Networks written by J. T. Groenewald and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Orthogonal Frequency Division Multiple Access Fundamentals and Applications written by Tao Jiang and published by CRC Press. This book was released on 2010-04-21 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supported by the expert-level advice of pioneering researchers, Orthogonal Frequency Division Multiple Access Fundamentals and Applications provides a comprehensive and accessible introduction to the foundations and applications of one of the most promising access technologies for current and future wireless networks. It includes authoritative cove

Download or read book Next Generation Passive Optical Networks Based on Orthogonal Frequency Division Multiplexing Techniques written by Francesc Xavier Escayola Elias and published by . This book was released on 2016 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent decades, the industry of communications has acquired huge significance, and nowadays constitutes an essential tool for the society information. Thus, the exponential growth in demand of broadband services and the increasing amount of information to be transmitted have spurred the evolution of the access network infrastructure to effectively meet the user needs in an effective way in terms of costs of both installation and maintenance. Passive optical networks (PON) are currently considered the most efficient and least costly alternative to deploy fiber to the home environment. In order to allow many users simultaneously coexist PONs based on time multiplexing (TDMA) have been developed. Looking ahead, however, it is expected that these techniques do not meet the requirements on access networks. In consequence, other multiple access techniques such as Wavelength Division Multiplexing Access (WDMA) or Orthogonal Frequency Division Multiplexing Access (OFDMA) are currently under study and development for use in the next generation of PONs. Particularly, in recent years OFDM has stood out among the scientific community to be considered a solution with great potential on future implementation of PONs. This is especially true due to the capacity of OFDM to work with multilevel modulations, its high tolerance to chromatic dispersion, and its high flexibility and granularity in terms of bandwidth management. Given the above, the aim of this Thesis is to study deeply the advantages and challenges of implementing the standard OFDM as an access network solution; likewise, it offers solutions to improve its performance. In order to evaluate the main structures and strategies for OFDM-based PON, a comparative analysis of all of them is performed firstly, highlighting their sensitivity levels, maximum range and number of users. A key aspect for network providers is the cost of operation, deployment and maintenance of networks. As a low-cost solution, this Thesis proposes a network model called Statistical-OFDMA-PON based on intensity modulation and direct detection. In addition, dynamic bandwidth management strategies are applied into this model getting an improvement in the power balance which in turn, allows to increase the maximum range and the scalability in number of users. One of the main OFDM problems is the Peak-to-Average Power Ratio (PAPR) which increases with the number of carriers. This thesis proposes a new algorithm based on folding the signal and transmitting auxiliary information in order to compensate the PAPR effect and thus increase the sensitivity of the optical system. On the other hand, OFDMA requires a large number of operations in the digital domain resulting in a high computational effort, which in turn results in an increased cost. For this reason, this Thesis presents a study on the optimization of the required resolution in the Digital-to-Analog / Analog-to-Digital Converters (DAC/ADCs) maintaining the transmission quality. The optimization of the computation time may make the OFDMA-based optical network more attractive for future PONs. Finally, another problem concerning the OFDM optical networks is their sensitivity to Phase Noise (PN). In this regard, this Thesis presents a study of the effect of the laser linewidth and its dependence on signal bandwidth. A mitigation technique based on pilot tones is implemented and the limiting values for the laser linewidth are found to be within the reach of present low-cost light sources.

Download or read book Orthogonal Frequency Division Multiplexed Access for Passive Optical Networks written by Ángel Peralta Gallardo and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: [ANGLÈS] Research activities for new alternatives in ultra fast transmission over optical fiber networks are looking towards Orthogonal Frequency Division Multiplexing (OFDM) which is used in different modern communication systems such as LTE, WiFi or WiMax because of the following reasons: tolerance to channel limitations, better spectral exploitation, scalability, flexibility and implementation feasibility with state of the art electronics. These benefits have been subject of major interest in Passive Optical Networks (PONs), which depend on reliable but low cost solutions to be commercialized. The adaptation of OFDM as an access scheme in PONs with cost effective Intensity Modulation with Direct Detection (IM/DD) can potentially deliver these benefits and be a next step in the evolution of high volume data access networks. The flexibility given by OFDM is applied as bandwidth granularity for the users in such way that each of them will be guaranteed with a certain level of service, yet the reconfigurability capabilities and bandwidth assignment for different users in a Optical Orthogonal Frequency Division Multiplexed Access (O-OFDMA) PON must be properly understood. The work reports the development of a test bed on IM/DD O-OFDMA for next generation PONs, in particular studying bandwidth assignment for different users for future Dynamic Bandwidth Allocation strategies.

Download or read book The ComSoc Guide to Passive Optical Networks written by Stephen B. Weinstein and published by John Wiley & Sons. This book was released on 2012-03-20 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the major architectures, standards, and technologies of Passive Optical Networks (PONs) The ComSoc Guide to Passive Optical Networks provides readers with a concise explanation of the key features of Passive Optical Networks (PONs); the different types of PON architectures and standards; key issues of PON devices, management, and implementation; and the promising business opportunities in access networks. Written for a broad audience, ranging from developers to users, this indispensable book provides an understanding o the evolutionary path of PON access systems and their positioning with respect to the cable, copper, and wireless competitors for broadband access networks. In addition, The ComSoc Guide to Passive Optical Networks: Provides brief, high-level overviews of the architectures and applications of Fiber-to-the-Home (FTTH) or Fiber-to-the-Curb (FTTC) access networks and the alternative HFC, subscriber line, and WiMAX access systems Awards readers with a clear understanding of what BPON, GPON, WDM-PON and EPON are and how they work, together with an introduction to their respective standards Carefully defines all acronyms and technical terms, making the book accessible to those who may not be specialists in this area Gives readers an appreciation of the last mile problems in telecommunications access networks, and the opportunities in optical-wireless integration

Download or read book A Novel Multi band CO OFDM Based Long Reach Passive Optical Network Architecture written by Mohamed Ben Zeglam and published by . This book was released on 2017 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis investigates a new long-reach passive optical networks (LRPON) architecture based on multi-band coherent optical orthogonal frequency division multiplexing (CO-OFDM). The proposed CO-OFDM based LRPON system is characterized by a novel phase noise compensation mechanism aiming to deal with optical signal dispersion in long-range transmissions. By employing a dispersion compensating fiber (DCF) and local oscillator (LO) laser phase shifter for each end-to-end transmission between OLT and ONU, we will show the phase noise due to dispersion can be effectively mitigated. Simulation of the downlink traffic between one optical line terminal (OLT) and 12 optical network units (ONUs) is performed successfully at different fiber lengths, at the data rate of 10$Gbps$ per ONU. The required BER for the forward error correction (FEC) has been achieved for most ONUs, using a dispersion compensating fiber (DCF) and local oscillator (LO) laser phase shifter to compensate for the chromatic dispersion (CD) and the polarization mode dispersion (PMD), respectively.

Download or read book Optical Orthogonal Frequency Division Systems with Direct Detection Receivers written by Juan Miguel Pérez Rosas and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: [ANGLÈS] The new generation of Pasive Optical Networks (PONs) to cover the last-mile to the user, is today a hot topic of research. Stringent performance requirements are both capacity and reach; these, together with reduced cost lead to consideration of a new paradigm. In this context, Optical OFDM (O-OFDM) is regarded as a promising candidate. From the many architectures being proposed for O-OFDM, the use of Direct Detection is particularly interesting for the downlink of Passive Optical Networks as cost-efficient Optical Network Units (ONUs) are required. In this line, this work encompasses a general study of Direct Detection Optical OFDM (DD O-OFDM) communications systems with emphasis on applications to optical Access Networks. It proposes designs for the downstream links of three different access network topologies differentiated by the optical modulation used: an Intensity Modulation (IM) with a Directly Modulated Laser (DML) an IM with a Mach-Zehnder Modulator (MZM) and an Amplitude modulation also with a MZM. All systems are based on Direct Detection receivers and the transmission of O-OFDM signals. The architectures, establish a wavelength agnostic link by transmitting Double Side Band signals. The impairments of a DSB transmission are studied and parting from them an optimization on the network?s parameters of frequency Guard Band and Carrier to Signal Power Ratio is performed. In order to test the architectures and optimize the parameters, simulations were executed using the commercial software VPI Transmission Maker TM. The testing of the architectures was done by minimizing receiver sensitivity at a BER 10-3 for data rates of 10Gbps and 40Gbps using 4-QAM and 16-QAM respectively, as digital modulation formats. Results show that spectral occupancy of the O-OFDM signal and the CSPR can be optimized while at the same time compensating for DSB impairments such as amplitude fading. Also the advantages and disadvantages of each optical modulation format depending on data rates and link?s distances required as well as cost-effectiveness are tested and described.

Download or read book DSP enabled Reconfigurable Optical Network Devices and Architectures for Cloud Access Networks written by Xiao Duan and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Orthogonal Frequency Division Multiplexing Access Based Passive Optical Network written by Cheng Li and published by . This book was released on 2009 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Orthogonal Frequency division Multiplexing for Optical Communications written by Daniel Jose Fernandes Barros and published by Stanford University. This book was released on 2011 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The drive towards higher spectral efficiency and maximum power efficiency in optical systems has generated renewed interest in the optimization of optical transceivers. In this work, we study the different optical applications: Wide Area Networks (WANs), Metropolitan Area Networks (MANs), Local Area Networks (LANs) and Personal Area Networks (PANs). In WANs or long-haul systems, orthogonal frequency-division multiplexing (OFDM) can compensate for linear distortions, such as group-velocity dispersion (GVD) and polarization-mode dispersion (PMD), provided the cyclic prefix is sufficiently long. Typically, GVD is dominant, as it requires a longer cyclic prefix. Assuming coherent detection, we show how to analytically compute the minimum number of subcarriers and cyclic prefix length required to achieve a specified power penalty, trading off power penalties from the cyclic prefix and from residual inter-symbol interference (ISI) and inter-carrier interference (ICI). We derive an analytical expression for the power penalty from residual ISI and ICI. We also show that when nonlinear effects are present in the fiber, single-carrier with digital equalization outperforms OFDM for various dispersion maps. We also study the impairments of electrical to optical conversion when using Mach-Zehnder (MZ) modulators. OFDM has a high peak-to-average ratio (PAR), which can result in low optical power efficiency when modulated through a Mach-Zehnder (MZ) modulator. In addition, the nonlinear characteristic of the MZ can cause significant distortion on the OFDM signal, leading to in-band intermodulation products between subcarriers. We show that a quadrature MZ with digital pre-distortion and hard clipping is able to overcome the previous impairments. We consider quantization noise and compute the minimum number of bits required in the digital-to-analog converter (D/A). Finally, we discuss a dual-drive MZ as a simpler alternative for the OFDM modulator, but our results show that it requires a higher oversampling ratio to achieve the same performance as the quadrature MZ. In MANs, we discuss the use OFDM for combating GVD effects in amplified direct-detection (DD) systems using single-mode fiber. We review known direct-detection OFDM techniques, including asymmetrically clipped optical OFDM (ACO-OFDM), DC-clipped OFDM (DC-OFDM) and single-sideband OFDM (SSB-OFDM), and derive a linearized channel model for each technique. We present an iterative procedure to achieve optimum power allocation for each OFDM technique, since there is no closed-form solution for amplified DD systems. For each technique, we minimize the optical power required to transmit at a given bit rate and normalized GVD by iteratively adjusting the bias and optimizing the power allocation among the subcarriers. We verify that SSB-OFDM has the best optical power efficiency among the different OFDM techniques. We compare these OFDM techniques to on-off keying (OOK) with maximum-likelihood sequence detection (MLSD) and show that SSB-OFDM can achieve the same optical power efficiency as OOK with MLSD, but at the cost of requiring twice the electrical bandwidth and also a complex quadrature modulator. We compare the computational complexity of the different techniques and show that SSB-OFDM requires fewer operations per bit than OOK with MLSD. In LANs, we compare the performance of several OFDM schemes to that of OOK in combating modal dispersion in multimode fiber links. We review known OFDM techniques using intensity modulation with direct detection (IM/DD), including DC-OFDM, ACO-OFDM and pulse-amplitude modulated discrete multitone (PAM-DMT). We describe an iterative procedure to achieve optimal power allocation for DC-OFDM, and compare analytically the performance of ACO-OFDM and PAM-DMT. We also consider unipolar M-ary pulse-amplitude modulation (M-PAM) with minimum mean-square error decision-feedback equalization (MMSE-DFE). For each technique, we quantify the optical power required to transmit at a given bit rate in a variety of multimode fibers. For a given symbol rate, we find that unipolar M-PAM with MMSE-DFE has a better power performance than all OFDM formats. Furthermore, we observe that the difference in performance between M-PAM and OFDM increases as the spectral efficiency increases. We also find that at a spectral efficiency of 1 bit/symbol, OOK performs better than ACO-OFDM using a symbol rate twice that of OOK. At higher spectral efficiencies, M-PAM performs only slightly better than ACO-OFDM using twice the symbol rate, but requires less electrical bandwidth and can employ analog-to-digital converters at a speed only 81% of that required for ACO-OFDM. In PANs, we evaluate the performance of the three IM/DD OFDM schemes in combating multipath distortion in indoor optical wireless links, comparing them to unipolar M-PAM with MMSE-DFE. For each modulation method, we quantify the received electrical SNR required at a given bit rate on a given channel, considering an ensemble of 170 indoor wireless channels. When using the same symbol rate for all modulation methods, M-PAM with MMSE-DFE has better performance than any OFDM format over a range of spectral efficiencies, with the advantage of M-PAM increasing at high spectral efficiency. ACO-OFDM and PAM-DMT have practically identical performance at any spectral efficiency. They are the best OFDM formats at low spectral efficiency, whereas DC-OFDM is best at high spectral efficiency. When ACO-OFDM or PAM-DMT are allowed to use twice the symbol rate of M-PAM, these OFDM formats have better performance than M-PAM. When channel state information is unavailable at the transmitter, however, M-PAM significantly outperforms all OFDM formats. When using the same symbol rate for all modulation methods, M-PAM requires approximately three times more computational complexity per processor than all OFDM formats and 63% faster analog-to-digital converters, assuming oversampling ratios of 1.23 and 2 for ACO-OFDM and M-PAM, respectively. When OFDM uses twice the symbol rate of M-PAM, OFDM requires 23% faster analog-to-digital converters than M-PAM but OFDM requires approximately 40% less computational complexity than M-PAM per processor.

Download or read book Intensity Modulation and Direct Detection OFDM Dimensioning for Next generation Passive Optical Networks written by Bruno Alberto Calmels and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: [ANGLÈS] A cost-effective architecture for next-generation passive optical networks is designed and dimensioned, based on intensity modulation and direct detection optical orthogonal frequency division multiple access.

Download or read book Optical Code Division Multiple Access written by Ken-ichi Kitayama and published by Cambridge University Press. This book was released on 2014-04-10 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive guide to optical fiber communications, from the basic principles to the latest developments in OCDMA for Next-Generation Fiber-to-the-Home (FTTH) systems. Part I starts off with the fundamentals of light propagation in optical fibers, including multiple access protocols, and their enabling techniques. Part II is dedicated to the practical perspectives of Next-Generation Fiber-to-the-Home (FTTH) technology. It covers the key building blocks of OCDMA, devices such as optical encoders and decoders, signal impairments due to noise, and data confidentiality, a unique property of OCDMA. This is followed by hybrid system architectures with TDM and WDM and practical aspects such as system cost, energy efficiency and long-reach PONs. Featuring the latest research, with cutting-edge coverage of system design, optical implementations, and experimental demonstrations in test beds, this text is ideal for students, researchers and practitioners in the industry seeking to obtain an up-to-date understanding of optical communication networks.

Download or read book OFDM for Optical Communications written by William Shieh and published by Academic Press. This book was released on 2010 with total page 440 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 Passive Optical Networks written by and published by Information Gatekeepers Inc. This book was released on 1990 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multidimensional Modulations in Optical Communication Systems written by Silvello Betti and published by CRC Press. This book was released on 2021-08-19 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book analyzes novel possibilities offered to the telecommunication engineer in designing tomorrow’s optical networks. Currently, optical and optoelectronic technologies make possible the realization of high-performance optical fiber communication systems and networks with the adoption of WDM configurations and both linear and nonlinear optical amplifications. The last step for increasing network throughput is represented by the implementation of multidimensional modulation formats in coherent optical communication systems, which enable increasing the bit rate/channel toward 400 Gbit/s/channel and beyond. Following this approach, the main emphasis is placed on innovative optical modulations. Multidimensional Modulations in Optical Communication Systems is an essential guide to the world of innovative optical communications from the point of view of growing capacity and security. It guides researchers and industries with the aim to exploring future applications for optical communications.

Download or read book Orthogonal Time Frequency Space Modulation written by Suvra Sekhar Das and published by CRC Press. This book was released on 2022-09-01 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last few decades wireless communications, especially Mobile Communication Technology, has evolved by leaps and bounds. The mobile communication industry has named the different major changes as generations namely 1G, 2G,..5G. We are presently looking at deployment of 5G technologies. The work for 6G has already started. This book is focused on the waveform design of 6G. It presents a discourse on a potential waveform for 6G namely Orthogonal Time Frequency Space (OTFS) modulation. OTFS has a distinct feature when compared to earlier generation waveforms such that information bearing signal is placed in the delay Doppler domain as opposed to the usual placement of such signals in the time-frequency domain. This unique feature of OTFS enables it to overcome several disadvantages of a very popular and highly successful waveform namely Orthogonal Frequency Division Multiplexing (OFDM). OTFS is known to be more resilient to frequency offset and Doppler which is one of the key drawbacks of OFDM. With this feature, OTFS, can support higher mobility as well as higher frequency bands of operation which is also one of the key requirements of the next generation wireless communication technologies. The implementation complexity of OTFS remains comparable to that of OFDM. It is found that OTFS provides significant SNR advantage, higher resilience, lower PAPR, lower out of band signal leakage and higher multi-user spectral efficiency than that of OFDM. This book addresses• Fundamental signal model of OTFS. • Receiver design for OTFS• Channel estimation in OTFS• Multiple Access through non-orthogonal multiple access (NOMA-OTFS) The contents of the books are primarily outcome of the research work done at the G. S. Sanyal School of Telecommunications, Indian Institute of Technology Kharagpur, Kharagpur, India. Orthogonal Time Frequency Space Modulation : A waveform for 6G is ideal for personnel the wireless communication industry as well as academic staff and master/research students in electrical engineering with a specialization in wireless communications.

Download or read book Orthogonal Frequency Division Multiplexing in Optical Communication Systems written by Dr. Ashad Ullah Qureshi and published by Concepts Books Publication. This book was released on 2022-06-01 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical fiber communication has emerged as a high potential substitute for communication methods such as twisted pair and coaxial wire. The main advantage of optical fiber over previous methods is to have higher capacity of data rate transmission. The conventional types of modulation and demodulation technique, which have been used through optical fiber communication system are Wavelength Division Multiplexing (WDM) technique and Dense Wavelength Division Multiplexing (DWDM) technique so far.