A Survey on OFDM-Based Elastic Core Optical Networking <s> III. OPTICAL OFDM TRANSMISSION TECHNOLOGY <s> A novel optical signal modulation concept of adaptively modulated optical orthogonal frequency-division multiplexing (AMOOFDM) is proposed and numerical simulations of the transmission performance of AMOOFDM signals are undertaken in unamplified multimode fiber (MMF)-based links using directly modulated distributed feedback lasers (DMLs). It is shown that 28 Gb/s intensity modulation and direct-detection AMOOFDM signal transmission over 300-m MMFs is feasible in unamplified DML-based links having 3-dB bandwidths of 150MHz/km. In addition, AMOOFDM is less susceptible to modal dispersion and variation in launching conditions when compared with existing schemes. <s> BIB001 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> III. OPTICAL OFDM TRANSMISSION TECHNOLOGY <s> The authors propose an adaptive orthogonal frequency division multiplexing (OFDM) system for communications over the indoor wireless diffuse optical channel. This channel can be characterised as short-term stationary, with severe attenuation and multipath-induced penalty, and high dependence on the space distribution of emitters and receivers. We have chosen OFDM systems because of their capability of supporting high data rates without channel equalisation. They also mitigate the quality of service fluctuations induced when space distribution of emitters and receivers varies. The performance of the new proposed scheme is compared with that of an adaptive system described in a previous work. The obtained results show that a significant increase of the system throughput is attained over noisy wireless optical channels. <s> BIB002 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> III. OPTICAL OFDM TRANSMISSION TECHNOLOGY <s> Using discrete multi-tone modulation with up to 64-QAM mapping, 24-Gb/s transmission is experimentally demonstrated over 730 m of MMF by direct modulation of an 850-nm VCSEL and direct detection with a MMF receiver. <s> BIB003 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> III. OPTICAL OFDM TRANSMISSION TECHNOLOGY <s> Optical wireless (OW) technology is attractive for short-range high-speed transmission, especially in RF sensitive environments or where secure applications are desired. We consider transmission over a broadband OW channel, present in the non-directed line-of-sight (LOS) link. For communication, we assume a system concept based on a modulation-adaptive OFDM (DMT). Such system offers efficient channel capacity exploitation, while avoiding inconvenient pointing and tracking mechanisms. Moreover, it allows deployment of simple optical components and efficient electrical signal processing. We first show that the dynamically adaptive system can provide great transmission rate enhancements compared to the statically designed one, even assuming a very conservative constraint on the electrical signal waveform (i.e., no clipping). Then, we show that significant further improvements can be achieved by tolerating some clipping, at the cost of accepting a minor increase of the symbol error rate. <s> BIB004 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> III. OPTICAL OFDM TRANSMISSION TECHNOLOGY <s> 1-Gbit/s transmission is demonstrated over 50 m of step-index PMMA plastic optical fiber (1-mm core-diameter) using a commercial light-emitting diode. This is enabled by use of discrete multitone modulation with up to 64-QAM constellation mapping. <s> BIB005 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> III. OPTICAL OFDM TRANSMISSION TECHNOLOGY <s> This paper describes coherent optical orthogonal frequency division multiplexing (CO-OFDM) techniques for the long-haul transmission of 100-Gb/s-class channels. First, we discuss the configurations of the transmitter and receiver that implement the optical multiplexing/demultiplexing techniques for high-speed CO-OFDM transmission. Next, we review the no-guard-interval (No-GI) CO-OFDM transmission scheme which utilizes optical multiplexing for OFDM signal generation and the intradyne receiver configuration with digital signal processing (DSP). We examine the transmission characteristics of the proposed scheme, and show that No-GI CO-OFDM offers compact signal spectra and superior performance with regard to tolerance against optical amplifier noise and polarization-mode dispersion (PMD). We then introduce long-haul high-capacity transmission experiments employing No-GI CO-OFDM; 13.4 Tb/s (134 times 111 Gb/s) transmission is successfully demonstrated over 3600 km of ITU-T G.652 single-mode fiber without using optical dispersion compensation. <s> BIB006 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> III. OPTICAL OFDM TRANSMISSION TECHNOLOGY <s> The first book on optical OFDM by the leading pioneers in the field. The only book to cover error correction codes for optical OFDM. It gives applications of OFDM to free-space communications, optical access networks, and metro and log haul transports show optical OFDM can be implemented. It 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. <s> BIB007 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> III. OPTICAL OFDM TRANSMISSION TECHNOLOGY <s> We develop a dynamic multi-band OFDM subcarrier allocation scheme to fully utilize the available bandwidth under the restriction of dispersion- and chirp-related power fading. The experimental results successfully demonstrate an intensity-modulation-direct-detection 34.78-Gbps OFDM signal transmissions over 100-km long-reach (LR) passive-optical networks (PONs) based on a cost-effective 10-GHz EAM and a 10-GHz PIN. Considering 0-100-km transmission bandwidth of a 10-GHz EAM, the narrowest bandwidth is theoretically evaluated to occur at ~40 km, instead of 100 km. Consequently, the performances of 20-100-km PONs are experimentally investigated, and at least 33-Gbps capacity is achieved to support LR-PONs of all possible 20-100-km radii. <s> BIB008 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> III. OPTICAL OFDM TRANSMISSION TECHNOLOGY <s> Fast advancing silicon technology underpinned by Moore's law is creating a major transformation in optical fiber communications. The recent upsurge of interests in optical orthogonal frequency-division multiplexing (OFDM) as an efficient modulation and multiplexing scheme is merely a manifestation of this unmistakable trend. Since the formulation of the fundamental concept of OFDM by Chang in 1966 and many landmark works by others thereafter, OFDM has been triumphant in almost all the major RF communication standards. Nevertheless, its application to optical communications is rather nascent and its potential success in the optical domain remains an open question. This tutorial provides a review of optical OFDM slanted towards emerging optical fiber networks. The objective of the tutorial is two-fold: (i) to review OFDM fundamentals from its basic mathematical formation to its salient disadvantages and advantages, and (ii) to reveal the unique characteristics of the fiber optical channel and identify the challenges and opportunities in the application of optical OFDM. <s> BIB009
Because of the great success of OFDM in wireless and broadband access networks, it is being adopted as an optical BIB006 [11], multimode fiber (MMF) BIB001 BIB003 , plastic optical fiber (POF) BIB005 , OFDM-PON (Passive Optical Network) BIB008 , and optical wireless communication systems (OWC) BIB002 BIB004 . In this paper, we mainly consider the single-mode fiber OFDM systems, to address the core optical network architecture discussed later in Section IV. Currently, there are many different implementations of O-OFDM BIB009 . Various classifications exist to describe different O-OFDM schemes. In BIB007 [22] [23] , two main forms of optical OFDM have been described as direct-detection optical OFDM (DD-OOFDM) and coherent optical OFDM (CO-OFDM), based on the signal detection technology used. In BIB006 , three types of optical CO-OFDM system are classified to be FFTBased CO-OFDM, All-Optical OFDM, and Electro-Optical OFDM, from both the signal synthesis and detection method perspectives. In this paper, we describe optical OFDM schemes using two dimensions: signal synthesis mechanism (electrical and optical) and signal detection mechanism (direct detection and coherent detection), respectively, as depicted in Fig. 5 . ElectroOptical OFDM proposed in BIB006 was classified into the optical signal synthesis category.