Analysis Of Coherent Random Carrier Code Division Multiple Access For High Capacity Optical Networks

In this paper provides an accurate analysis of the performance of a random-carrier (RC) code-division multiple-access (CDMA) scheme recenily introduced for use in high-capacity optical networks. According to this scheme coherent optical techniques are employed to exploit the huge bandwidth of single-mode optical fibers and are coupled with spread spectrum direct-sequence modulation in order to mitigate the interference from other signals due to the frcquency overlap caused by the instability of the carrier frequency of the laser, or to the mistakes in the frequency coordination and assignment. The average bit error pmbability of this multiplexing scheme is evaluated by using the characteristic function of the other-user interference at the output of the matched optical filter. Both phase noise and thermal noise (AWGN) are taken into account in the computation. Both synchronous and asynchronous Systems are analyzed in this context. The analysis is valid for any spreading gain and any number of interfering users and makes very limited use of approximations. The performance evaluation of RC CDMA establishes the potential advantage in employing hybrids of WDMA (wavelength-division multiple-access) and CDMA multiplexing to combat inter-carrier interference in dense WDMA systems.

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.

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.

A self-contained guide to OCDMA for Next-Generation FTTH systems, from the fundamentals to cutting-edge research and practical perspectives.

This thesis investigates the performance of a hybrid modulation scheme, combining subcarrier multiplexing and code division multiple access. This scheme may be useful in tomorrow's optical local area networks to take advantage of the capacity of optical fibers using commercially available optical technology. The application of subcarrier multiplexing to optical local networks has generated much interest recently, however it is sensitive to nonlinear distortion generated by the laser diodes used to transmit data over the optical network. Earlier research has indicated that combining code division multiple access with subcarrier multiplexing may provide improved performance. However the lasers' nonlinearity has not been specifically included in earlier research, due to the complexity of the analysis. In this thesis a simulation is used to evaluate the performance of the hybrid SCM-CDMA optical network. A custom program was written in the C language for this purpose. Preliminary results from the simulation program indicate that the performance of subcarrier multiplexed signals sent over an optical network may improve fairly substantially if code sequences are used to spread the bandwidth of information signals prior to optical transmission.