Download or read book Investigation of Coherent Spectral and Incoherent Wavelength time Optical Code Division Multiple Access O CDMA Systems written by Vincent Jose Hernandez and published by . This book was released on 2007 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 305 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 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 Code Division Multiple Access Systems in AlGaInAs written by Mohsin Haji and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The rise of photonic integration makes optical code division multiple access (OCDMA) worth revisiting due to its promising role in future all-optical networks. OCDMA has the potential to exploit the surplus bandwidth of optical fibres and to carry over to the optical domain the benefits seen CDMA radio communication systems, such as the effective sharing of the spectrum for multiple network subscribers, and resistance to jamming and eavesdropping. One of the major requirements for the deployment of OCDMA in networks is integration. This thesis presents a research study of integrated OCDMA systems using the AlGaInAs/InP semiconductor material system. This material is considered due to its useful intrinsic properties such as thermal stability, strong electron confinement, and low threshold, making it suitable for fabricating optoelectronic devices. Two bespoke OCDMA systems are considered for integration: coherent temporal phase coding (TPC), and incoherent wavelength-hopping time-spreading (WHTS) OCDMA systems. TPC systems are excellent for high speed communications due to their static en/decoding enabling features. In this research, a 2×2 asymmetric Mach Zehnder interferometer (AMZI) is used to generate a 2-bit phase code, allowing multiplexing for up to four users. A semiconductor mode-locked ring laser is also embedded in the circuit, and using a synchronous mode-locking method, adequate signal en/decoding is achieved. WHTS systems on the other hand fully exploit the spectral and temporal space available in networks by assigning each user with a unique wavelength-time hop sequence for en/decoding data signals. Here, a mode-locked laser array is used with intracavity distributed Bragg reflectors (DBRs) for spectrally tuning each laser, and a 4:1 multimode interference coupler is used to combine the laser signals into a single channel for amplification, modulation and transmission. The integrated system is fully characterised and synchronisation experiments are performed to show the potential for its use in high speed multi-user networks. Mode-locked lasers play an important role in many OCDMA implementations due to their wide spectrum and discrete temporal properties, which can be easily exploited during data en/decoding. Various mode-locked laser devices have been studied during this research with additional embedded components such as intracavity DBRs and phase controllers for precise tuning of the wavelength and pulse repetition frequency. However, the noisy nature of passively operating mode-locked lasers make them prone to high jitter, which can result in high bit error rates. Synchronisation schemes are thereby explored in order to temporally stabilise the pulse oscillations to make them suitable for use in long haul transmission systems. This includes synchronous and hybrid mode-locking, as well as a passive technique using an optical fibre loop to provide phase feedback, which is shown to promote ultralow RF linewidths in mode-locked lasers.

Download or read book Optical CDMA System Based on Spectral Amplitude Encoding of Incoherent Broadband Sources written by Lucie Adam and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, a new optical Code-Division-Multiple Access (CDMA) system is demonstrated based on spectral amplitude encoding of noncoherent broadband sources. This scheme employs low-cost optical sources such as light-emitting diodes (LEDs). The spreading gain is independent of the data rate, therefore individual users can operate at data rates compatible with available electronic devices. Optical CDMA systems are generally classified into two categories: time-encoded and frequency-encoded systems. In the former case, a low information rate is mapped into a high rate optical pulse sequence. This is possible because of the wide bandwidth of optical fibers. The latter relies on encoding the entire available wavelength band at once with a sequence identifying the intended user. The encoding and decoding principles rely solely upon the crosscorrelation properties exhibited by the set of signals used to distinguish subscribers. We employ simple maximal-length sequences. We demonstrate how data is recovered or rejected with the use of a differential receiver. We examine the transceiver design, and the impact of their characteristics on the system capacity. The performance of the proposed CDMA system is experimentally characterized. The experimental set-up and its advantages and limitations are detailed. We present our bit-error rate (BER) measurements for different code lengths and received power. Also, the resulting eye patterns are shown.

Download or read book A Spectral Phase Encoded Time Spreading Optical Code Division Multiple Access Testbed written by Wei Cong and published by . This book was released on 2006 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 2 D Extended EDW the New Scheme of Two Dimensional Wavelength time Coding for Optical Code Division Multiple Access System written by Nurolhuda Mohd Noor and published by . This book was released on 2016 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: In OCDMA system, designing a successful code for isolating the users is one of the main issues that has to be tackled, due to its importance to mitigate the deleterious effect of MAI. The research presented in this thesis focuses on the code design of incoherent 2-D spectral temporal, SAC OCDMA system, namely 2-D Extended EDW code. Fig. 1. 1 illustrates the scope of the research, it is shown that the research will be focus on the family of Spectral Amplitude Coding (SAC) codes, and used wavelength-time or spectral-temporal technique to perform 2-D coding in OCDMA system.

Download or read book Optical Code division Multiple Access Networks Quantifying and Achieving the Ultimate Performance written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optoelectronics Engineering and Information Technologies in Industry written by D.A. Li and published by Trans Tech Publications Ltd. This book was released on 2013-09-18 with total page 2320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collection of selected, peer reviewed papers from the 2013 2nd International Conference on Opto-Electronics Engineering and Materials Research (OEMR 2013), October 19-20, 2013, Zhengzhou, Henan, China. The 467 papers are grouped as follows: Chapter 1: Optoelectronic, Communication Technology and Applications; Chapter 2: Materials Science Engineering; Chapter 3: Mechatronics, Control and Management, Testing, Measurement and Monitoring Technologies; Chapter 4: Image Processing Technology and Methodology, Recognize Technologies; Chapter 5: Computing Methods and Algorithms, Automation and Information Technologies, CAD Applications.

Download or read book Notice g ologique sur la formation n ocomienne dans le d partement de l Ain written by and published by . This book was released on 1842 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Coherent Random carrier Code division Multiple access for High capacity Optical Networks written by B. Ghaffari and published by . This book was released on 1992 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Program Proceedings written by and published by . This book was released on 1996 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Compressed Sensing in Li Fi and Wi Fi Networks written by Malek Benslama and published by Elsevier. This book was released on 2017-11-20 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compressed Sensing in Li-Fi and Wi-Fi Networks features coverage of the first applications in optical telecommunications and wireless. After extensive development of basic theory, many techniques are presented, such as non-asymptotic analysis of random matrices, adaptive detection, greedy algorithms, and the use of graphical models. The book can be used as a comprehensive manual for teaching and research in courses covering advanced signal processing, efficient data processing algorithms, and telecommunications. After a thorough review of the basic theory of compressed sensing, many mathematical techniques are presented, including advanced signal modeling, Nyquist sub-sampling of analog signals, the non-asymptotic analysis of random matrices, adaptive detection, greedy algorithms, and the use of graphical models. Offers extensive development of basic theory behind telecommunications and wireless networks Contains broad coverage of treat compressed sensing, including electromagnetism signals Provides insights into the two key areas of telecommunications, WIFI and LIFI Includes information on advanced signal modeling, Nyquist sub-sampling of analog signals, the non-asymptotic analysis of random matrices, adaptive detection, greedy algorithms, and more

Download or read book Optical Cdma Spectral Encoder Decoder written by Neetika Soni and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, there has been increasing interest in field of Optical CDMA due to its potential for offering unmatched features at ultra high data rates in field of local and metro area networks. OCDMA exhibits as an attractive alternative for broadband fiber optic multiple access networks among other optical multiplexing technologies such as OTDMA (Optical Time Division Multiple Access) and WDMA (Wavelength Division Multiple Access) Optical CDMA is a technique where different codes are assigned to different users. Each user data bit is spreaded according to the code allotted to it.Aim of the book is to discuss very simple method of Optical CDMA encoding technique known as the Temporal Phase Encoding and the performance of the system with this encoding technique is evaluated on the basis of number of users, length of the spreading code for 4-phase and 8-phases. Simulation results for the system are presented for upto seven users. Bit error rate curves are plotted with data rate of 1Gbps.