Download or read book Applications of Perfect Difference Codes in Fiber optics and Wireless Optical Code division Multiplexing multiple access Systems written by Fahim Aziz Umrani and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: After establishing itself in the radio domain, Spread spectrum code-division multiplexing/multiple-access (CDMA) has seen a recent upsurge in optical domain as well. Due to its fairness, flexibility, service differentiation and increased inherent security, CDMA is proved to be more suitable for the bursty nature of local area networks than synchronous multiplexing techniques like Frequency/Wavelength Division Multiplexing (F/WDM) and Time Division Multiplexing (TDM). In optical domain, CDMA techniques are commonly known as Optical-CDMA (O-CDMA). All optical CDMA systems are plagued with the problem of multiple-access interference (MAI). Spectral amplitude coding (SAC) is one of the techniques used in the literature to deal with the problem of MAI. The choice of spreading code in any CDMA system is another way to ensure the successful recovery of data at the receiving end by minimizing the effect of MAI and it also dictates the hardware design of the encoder and decoder. This thesis focuses on the efficient design of encoding and decoding hardware. Perfect difference codes (PDC) are chosen as spreading sequences due to their good correlation properties. In most of the literature, evaluation of error probability is based on the assumptions of ideal conditions. Such assumptions ignore major physical impairments such as power splitting losses at the multiplexers of transmitters and receivers, and gain losses at the receivers, which may in practice be an overestimate or underestimate of the actual probability of error. This thesis aims to investigate thoroughly with the consideration of practical impairments the applications of PDCs and other spreading sequences in optical communications systems based on spectral-amplitude coding and utilizing codedivision as multiplexing/multiple-access technique. This work begins with a xix general review of optical CDMA systems. An open-ended practical approach has been used to evaluate the actual error probabilities of OCDM/A systems under study. It has been concluded from results that mismatches in the gains of photodetectors, namely avalanche photodiode (APDs), used at the receiver side and uniformity loss in the optical splitters results in the inaccurate calculation of threshold level used to detect the data and can seriously degrade the system bit error rate (BER) performance. This variation in the threshold level can be compensated by employing techniques which maintain a constant interference level so that the decoding architecture does not have to estimate MAI every time to make a data bit decision or by the use of balanced sequences. In this thesis, as a solution to the above problem, a novel encoding and decoding architecture is presented for perfect difference codes based on common zero code technique which maintains a constant interference level at all instants in CDM system and thus relieves the need of estimating interference. The proposed architecture only uses single multiplexer at the transmitters for all users in the system and a simple correlation based receiver for each user. The proposed configuration not only preserves the ability of MAI in Spectral-Amplitude Coding SAC-OCDM system, but also results in a low cost system with reduced complexity. The results show that by using PDCs in such system, the influence of MAI caused by other users can be reduced, and the number of active users can be increased significantly. Also a family of novel spreading sequences are constructed called Manchestercoded Modified Legendre codes (MCMLCs) suitable for SAC based OCDM systems. MCMLCs are designed to be used for both single-rate and Multirate systems. First the construction of MCMLCs is presented and then the bit error rate performance is analyzed. Finally the proposed encoding/decoding architecture utilizing perfect difference codes is applied in wireless infrared environment and the performance is found to be superior to other codes.
Download or read book Optical Code Division Multiple Access written by Paul R. Prucnal and published by CRC Press. This book was released on 2018-10-03 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Code-division multiple access (CDMA) technology has been widely adopted in cell phones. Its astonishing success has led many to evaluate the promise of this technology for optical networks. This field has come to be known as Optical CDMA (OCDMA). Surveying the field from its infancy to the current state, Optical Code Division Multiple Access: Fundamentals and Applications offers the first comprehensive treatment of OCDMA from technology to systems. The book opens with a historical perspective, demonstrating the growth and development of the technologies that would eventually evolve into today's optical networks. Building on this background, the discussion moves to coherent and incoherent optical CDMA coding techniques and performance analysis of these codes in fiber optic transmission systems. Individual chapters provide detailed examinations of fiber Bragg grating (FBG) technology including theory, design, and applications; coherent OCDMA systems; and incoherent OCDMA systems. Turning to implementation, the book includes hybrid multiplexing techniques along with system examples and conversion techniques to connect networks that use different multiplexing platforms, state-of-the-art integration technologies, OCDMA network security issues, and OCDMA network architectures and applications, including a look at possible future directions. Featuring contributions from a team of international experts led by a pioneer in optical technology, Optical Code Division Multiple Access: Fundamentals and Applications places the concepts, techniques, and technologies in clear focus for anyone working to build next-generation optical networks.
Download or read book Optical Code Division Multiple Access Communication Networks written by Hongxi Yin and published by Springer Science & Business Media. This book was released on 2009-03-15 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical code division multiple access (OCDMA) communication network technology will play an important role in future optical networks, such as optical access and metropolitan area networks. OCDMA technology can also be applied to implement optical signal multiplexing and label switching on backbone networks. Optical Code Division Multiple Access Communication Networks - Theory and Applications introduces the code theory of OCDMA, the methods and technologies of OCDMA encoding and decoding, the theory and methods of analyzing OCDMA systems with various receiver models and realizing multiple-class services with different bit rates and QoS. In addition, OCDMA network architectures, protocols and applications are discussed in detail. The up-to-date theoretical and experimental results on OCDMA systems and networks are also reported. A large number of encoding/decoding examples and many analysis and simulation results of code and system performances are given. It is a valuable text and/or reference book for postgraduates majoring in telecommunication and photonics to obtain a well-knit theoretical foundation and for engineers in R&D and management of optical communications. Dr. Yin is an Associate Professor of the School of Electronics Engineering and Computer Science at Peking University, China, and was a Visiting Research Fellow of Optoelectronics Research Centre (ORC) at University of Southampton, UK. Dr. Richardson is a Professor for optical communications and Deputy Director of ORC at University of Southampton, UK, and is responsible for much of the ORC's fiber related activities.
Download or read book Optical CDMA Networks written by Hooshang Ghafouri-Shiraz and published by John Wiley & Sons. This book was released on 2012-04-04 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses heavily on the principles, analysis and applications of code-division multiple-access (CDMA) techniques in optical communication systems and networks. In this book, the authors intimately discuss modern optical networks and their applications in current and emerging communication technologies, evaluating the quality, speed and number of supported services. In particular, principles and fundamentals of optical CDMA techniques from beginner to advanced levels are heavily covered. Furthermore, the authors concentrate on methods and techniques of various encoding and decoding schemes and their structures, as well as analysis of optical CDMA systems with various transceiver models including advanced multi-level incoherent and coherent modulations with the architecture of access/aggregation networks in mind. Moreover, authors examine intriguing topics of optical CDMA networking, compatibility with IP networks, and implementation of optical multi-rate multi-service CDMA networks. Key features: Expanded coverage of optical CDMA networks, starts from principles and fundamentals Comprehensive mathematical modelling and analysis from signal to system levels Addresses the applications of modern optical networking in the current and emerging communication technologies Greater focus on advanced optical multi-level incoherent and coherent modulations, spreading codes, and transceiver designs Detailed hardware specifications, system-level block diagrams, and network nodes’ functionalities This book appeals to researchers, practicing engineers, and advanced students. It is a practical resource for readers with an interest in optical communications and networks.
Download or read book Optical Coding Theory with Prime written by Wing C. Kwong and published by CRC Press. This book was released on 2018-09-03 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although several books cover the coding theory of wireless communications and the hardware technologies and coding techniques of optical CDMA, no book has been specifically dedicated to optical coding theory—until now. Written by renowned authorities in the field, Optical Coding Theory with Prime gathers together in one volume the fundamentals and developments of optical coding theory, with a focus on families of prime codes, supplemented with several families of non-prime codes. The book also explores potential applications to coding-based optical systems and networks. Learn How to Construct and Analyze Optical Codes The authors use a theorem-proof approach, breaking down theories into digestible form so that readers can understand the main message without searching through tedious proofs. The book begins with the mathematical tools needed to understand and apply optical coding theory, from Galois fields and matrices to Gaussian and combinatorial analytical tools. Using a wealth of examples, the authors show how optical codes are constructed and analyzed, and detail their performance in a variety of applications. The book examines families of 1-D and 2-D asynchronous and synchronous, multilength, and 3-D prime codes, and some non-prime codes. Get a Working Knowledge of Optical Coding Theory to Help You Design Optical Systems and Networks Prerequisites include a basic knowledge of linear algebra and coding theory, as well as a foundation in probability and communications theory. This book draws on the authors’ extensive research to offer an authoritative reference on the emerging field of optical coding theory. In addition, it supplies a working knowledge of the theory and optical codes to help readers in the design of coding-based optical systems and networks. For more on the technological aspects of optical CDMA, see Optical Code Division Multiple Access: Fundamentals and Applications (CRC Press 2005).
Download or read book Telecommunications Engineering Principles And Practice written by Amoakoh Gyasi-agyei and published by World Scientific. This book was released on 2019-06-19 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers basic principles of telecommunications and their applications in the design and analysis of modern networks and systems. Aimed to make telecommunications engineering easily accessible to students, this book contains numerous worked examples, case studies and review questions at the end of each section. Readers of the book can thus easily check their understanding of the topics progressively. To render the book more hands-on, MATLAB® software package is used to explain some of the concepts. Parts of this book are taught in undergraduate curriculum, while the rest is taught in graduate courses.Telecommunications Engineering: Theory and Practice treats both traditional and modern topics, such as blockchain, OFDM, OFDMA, SC-FDMA, LPDC codes, arithmetic coding, polar codes and non-orthogonal multiple access (NOMA).
Download or read book Multiplexing written by Somayeh Mohammady and published by BoD – Books on Demand. This book was released on 2019-09-04 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mobile communication has been a critical part of everyday life for the last 30 years. As the demand for wireless communications and higher data rates on these links continues its rapid growth, engineers, scientists, and researchers are required to advance the hardware and software needed to deliver systems for 5G, Massive multiple-input, multiple-output (MIMO), and optical backhaul networks. Now, more than ever before, the fundamental concept of multiplexing is at play. This book is a unique reference for understanding the concept of multiplexing. It provides comprehensive coverage of the practical applications of multiplexing to help the reader better understand its use in these systems. It is a great resource, especially for engineers working on digital signal processing, radio frequency (RF), antenna design, beamforming, and network designs. The book contains chapters on the following topics: • History of multiplexing and how it applies to current technologies; • Different types and applications of multiplexing; • Multiplexing techniques in wireless networks; • Multiple-Input, Multiple-Output Orthogonal Frequency-Division Multiplexing (MIMO-OFD); • Direct-Sequence Optical-Code Division Multiple-Access (DS-OCDMA); • Optically multiplexed systems
Download or read book Coding for Optical Channels written by Ivan Djordjevic and published by Springer Science & Business Media. This book was released on 2010-04-05 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to adapt to the ever-increasing demands of telecommunication needs, today’s network operators are implementing 100 Gb/s per dense wavelength division multiplexing (DWDM) channel transmission. At those data rates, the performance of fiberoptic communication systems is degraded significantly due to intra- and inter-channel fiber nonlinearities, polarization-mode dispersion (PMD), and chromatic dispersion. In order to deal with those channel impairments, novel advanced techniques in modulation and detection, coding and signal processing are needed. This unique book represents a coherent and comprehensive introduction to the fundamentals of optical communications, signal processing and coding for optical channels. It is the first to integrate the fundamentals of coding theory with the fundamentals of optical communication.
Download or read book Design and Implementation of an Optical Code Division Multiple Access System Combined with Dense Wavelength Division Multiplexing written by Yongjun Zhang and published by Cuvillier Verlag. This book was released on 2003 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optical Code Division Multiple Access written by Ken-Ichi Kitayama and published by . This book was released on 2014 with total page 345 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 VLSI Communication and Signal Processing written by R. K. Nagaria and published by Springer Nature. This book was released on 2023-07-01 with total page 867 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers a variety of topics in Electronics and Communication Engineering, especially in the area of microelectronics and VLSI design, communication systems and networks, and signal and image processing. The content is based on papers presented at the 5th International Conference on VLSI, Communication and Signal Processing (VCAS 2022). The book also discusses the emerging applications of novel tools and techniques in image, video, and multimedia signal processing. This book is useful to students, researchers, and professionals working in the electronics and communication domain.
Download or read book Fiber optic Code Division Multiple Access written by Naser G. Tarhuni and published by . This book was released on 2007 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optical Coding Theory with Prime written by Wing C. Kwong and published by CRC Press. This book was released on 2018-09-03 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although several books cover the coding theory of wireless communications and the hardware technologies and coding techniques of optical CDMA, no book has been specifically dedicated to optical coding theory—until now. Written by renowned authorities in the field, Optical Coding Theory with Prime gathers together in one volume the fundamentals and developments of optical coding theory, with a focus on families of prime codes, supplemented with several families of non-prime codes. The book also explores potential applications to coding-based optical systems and networks. Learn How to Construct and Analyze Optical Codes The authors use a theorem-proof approach, breaking down theories into digestible form so that readers can understand the main message without searching through tedious proofs. The book begins with the mathematical tools needed to understand and apply optical coding theory, from Galois fields and matrices to Gaussian and combinatorial analytical tools. Using a wealth of examples, the authors show how optical codes are constructed and analyzed, and detail their performance in a variety of applications. The book examines families of 1-D and 2-D asynchronous and synchronous, multilength, and 3-D prime codes, and some non-prime codes. Get a Working Knowledge of Optical Coding Theory to Help You Design Optical Systems and Networks Prerequisites include a basic knowledge of linear algebra and coding theory, as well as a foundation in probability and communications theory. This book draws on the authors’ extensive research to offer an authoritative reference on the emerging field of optical coding theory. In addition, it supplies a working knowledge of the theory and optical codes to help readers in the design of coding-based optical systems and networks. For more on the technological aspects of optical CDMA, see Optical Code Division Multiple Access: Fundamentals and Applications (CRC Press 2005).
Download or read book New Codes and New Approaches for Code Division Multiple Access on Optical Fiber Networks written by Guu-Chang Yang and published by . This book was released on 1992 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Four Wave Mixing on Absolute Polar DCDM Wdm Fiber Optic Systems written by Aamir Khan and published by LAP Lambert Academic Publishing. This book was released on 2012-06 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: To use the available bandwidth in optical communication systems different multiplexing techniques are adopted, so that multiple users can access and use the bandwidth efficiently. The most common techniques are frequency division multiplexing, time division multiplexing, optical code division multiplexing, wave length division multiplexing and dense wavelength division multiplexing. Absolute Polar Duty Cycle Division Multiplexing over wave length division multiplexing technique is another technique which increases the channel count from other conventional existing systems. However, AP-DCDM-WDM system faces the non-linearities as like the other conventional system which affects the spectral efficiency. There is a need to study the effect of non linearities, especially effect of four wave mixing on this technique, to make this technique more efficient and powerful by taking suitable measures against the non-linearities.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1948 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development and Implemention of a Novel Code Family for Optical Code Divison Multiple Access System written by Syed Alwee Aljunid Syed Junid and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Future telecommunication systems and networks are expected to provide a variety of integrated broadband services to the customers. There has been a tremendous interest in applying Code Division Multiple Access (CDMA) techniques to fiber optic cOmIDunication systems. This technique is one of the multiple access schemes that is becoming popular because of the flexibility in the allocation of channels, ability to operate asynchronously, enhanced privacy and increased capacity in bursty networks. The performance of any Optical CDMA (OCDMA) system strongly depends on the codes properties. In this study we introduce a new code for Optical CDMA namely Double Weight Code family (DW). Double Weight Code (DW) has a basic fixed weight of 2 and exists for every natural number. The DW codes possess ideal cross correlation properties, which have important characteristics in OCDMA systems since these can eliminate multiple access interference (MAl) and reduce noise. Also proposed in this study, a Modified Double-Wei~ht (MDW) code, which is a variation ofDW code family that can have a variable weight greater than two. The MDW code possesses ideal cross¬correlation properties alid exists for every natural number too. It is shown through simulations, theoretical analysis and partially by the experiments that the transmission performance of DW code family is significantly better than that of existing codes such as Modified Frequency Hopping code (MFH) and Hadamard code. The performance of DW code family, MFH and Hadamard codes were simulated using commercial simulation software, OptiSystem Version 3.0. The performance of the systems was characterized by referring to the bit error rate (BER) and the eye patterns. DW code family has shown superior performance compared to other OCDMA codes. The simulated eye pattern of one of the four MDW coded carriers running at 10Gbps over a communication-standard fiber shows a good quality transmission at the BER of 10-12 as opposed to only Hr3 and 10-4 for Hadamard and MFH codes. In optical CDMA systems, the detection process affects the design of transmitters and receivers. Cross-correlation functions are generated which creates Multiple Access Interference (MAl) and this will degrade the system performance. MAl can be reduced by using subtraction techniques. The most common subtraction technique is the complementary subtraction technique and also known as balanced detection technique. In this thesis, we also introduce a new approach called AND subtraction technique. This method rejects unwanted signals that interfere with the original signals. Furthermore, the purpose of this new subtraction technique is to reduce the receiver complexity and increase system performance. It has been shown through theoretical analysis, simulation and experimental work, the performance of the system with AND subtraction technique can be improved significantly. Based on the theoretical analysis, BER as good as 10-12 is achieved at the bit rate of 622 Mbps over 70 kIn distance.
