OFDM for Optical Communications
01 Jan 2009-Vol. 27, pp 189-204
TL;DR: This paper gives a tutorial overview of OFDM highlighting the aspects that are likely to be important in optical applications and the constraints imposed by single mode optical fiber, multimode optical fiber and optical wireless.
Abstract: Orthogonal frequency division multiplexing (OFDM) is a modulation technique which is now used in most new and emerging broadband wired and wireless communication systems because it is an effective solution to intersymbol interference caused by a dispersive channel. Very recently a number of researchers have shown that OFDM is also a promising technology for optical communications. This paper gives a tutorial overview of OFDM highlighting the aspects that are likely to be important in optical applications. To achieve good performance in optical systems OFDM must be adapted in various ways. The constraints imposed by single mode optical fiber, multimode optical fiber and optical wireless are discussed and the new forms of optical OFDM which have been developed are outlined. The main drawbacks of OFDM are its high peak to average power ratio and its sensitivity to phase noise and frequency offset. The impairments that these cause are described and their implications for optical systems discussed.
Citations
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TL;DR: In this article, the nonlinear inverse synthesis (NIS) method is proposed for the continuous nonlinear signal spectrum, which can provide an effective eigenvalue division multiplexing with high spectral efficiency thanks to highly suppressed channel cross talk.
Abstract: In linear communication channels, spectral components (modes) defined by the Fourier transform of the signal propagate without interactions with each other. In certain nonlinear channels, such as the one modelled by the classical nonlinear Schr\"odinger equation, there are nonlinear modes (nonlinear signal spectrum) that also propagate without interacting with each other and without corresponding nonlinear cross talk; effectively, in a linear manner. Here, we describe in a constructive way how to introduce such nonlinear modes for a given input signal. We investigate the performance of the nonlinear inverse synthesis (NIS) method, in which the information is encoded directly onto the continuous part of the nonlinear signal spectrum. This transmission technique, combined with the appropriate distributed Raman amplification, can provide an effective eigenvalue division multiplexing with high spectral efficiency, thanks to highly suppressed channel cross talk. The proposed NIS approach can be integrated with any modulation formats. Here, we demonstrate numerically the feasibility of merging the NIS technique in a burst mode with high spectral efficiency methods, such as orthogonal frequency division multiplexing and Nyquist pulse shaping with advanced modulation formats (e.g., QPSK, 16QAM, and 64QAM), showing a performance improvement up to 4.5 dB, which is comparable to results achievable with multi-step per span digital back propagation.
119 citations
16 Nov 2011
TL;DR: In this paper, a group of seis tecnicas de reducao da PAPR is presented, as a contribuicao, uma tecnica de reducecao, which consiste of transmissao de sequencia parcial (PTS) and mapeamento seletivo.
Abstract: O objetivo deste trabalho e apresentar uma comparacao de desempenho de um
conjunto de tecnicas de reducao da PAPR. As tecnicas analisadas sao baseadas em
esquemas de mapeamento seletivo (SLM), transmissao de sequencia parcial (PTS) e
transformada de Walsh-Hadamard (WHT). Ao todo, tres derivacoes de esquemas SLM sao
avaliadas: SLM usando sequencias de maximo comprimento, SLM usando sequencias de
Hadamard e SLM usando sequencias com valores complexos. Alem de avaliar o PTS
convencional, este trabalho apresenta, como contribuicao, uma tecnica de reducao da
PAPR, que consiste da juncao das tecnicas PTS e SLM, doravante denominada PTSModificado.
Desta forma, um total de seis tecnicas sao avaliadas neste trabalho.
No trabalho existe uma descricao detalhada de cada uma destas tecnicas de
controle da PAPR e, tambem, e apresentada a eficiencia de reducao da PAPR das mesmas.
Isto e feito atraves do estudo da funcao densidade de probabilidade da PAPR, levantadas
por meio de simulacao computacional para cada caso. Alem da reducao da PAPR, este
trabalho tambem analisa o efeito destas tecnicas na probabilidade de erro de simbolo em
canais AWGN nao-lineares.
11 citations
Additional excerpts
...Já existem vários padrões que empregam essa técnica para prover serviços com altas taxas de transmissão, desde sistemas de comunicação sem fio até aplicações em fibras ópticas [2]....
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14 Jun 2017
TL;DR: A novel energy and spectrally efficient scheme called asymmetrically clipped absolute value optical OFDM (AAO-OFDM) is proposed for intensity-modulated direct-detection systems, which has lower peak-to-average power ratio and achieves better bit error rate performance compared to its counterparts for the same spectral efficiency.
Abstract: This dataset is associated with the 2017 JLT publication titled "Asymmetrically Clipped Absolute Value Optical OFDM for Intensity-Modulated Direct-Detection Systems" by Ruowen Bai et.al. This RDM includes the data set for plotting each of the result-figures of the above-mentioned paper. More explicitly, this RDM includes the data for plotting the x-axis and y-axis of a particular curve of the corresponding figure.
11 citations
Cites background or methods from "OFDM for Optical Communications"
...We could analyze the AAO-OFDM signals more comprehensively under the help of their PDF....
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...To improve the energy efficiency, ACO-OFDM is proposed, where only the odd subcarriers are utilized and the time-domain signals have antisymmetry property [15]–[17]....
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...We assume Y = |X|, and its PDF can be derived easily as fY (y) = 2fX (y)u(y), where u(y) is a unit step function with u(0) = 12 ....
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...Therefore, the frequency-domain symbols of ACO-OFDM are given by [15]–[17]...
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...Using the central limit theorem, it can be shown that the bipolar time-domain signals x(t) and y(t) follow a Gaussian distribution with zero mean [17], [27], [28], in which x(t) and y(t) are the output signals of the D/A for the input xn and yn , respectively....
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Dissertation•
27 Feb 2017
TL;DR: In this paper, a photonic mixer based on a SOA-MZI (Semiconductor Optical Amplifier Mach-Zehnder Interferometer) device and a sampling technique allowing both conversion towards high and low frequencies is studied.
Abstract: Frequency mixing is a key function existing in different systems, especially in mixed photonic-microwave ones. Today, the supremacy of optical networks to carry high bitrate data over large distances motivates the optical implementation of such functions to benefit from the low loss, high bandwidth, low size and weight of optical technologies. In this work, we study a photonic mixer based on a SOA-MZI (Semiconductor Optical Amplifier Mach-Zehnder Interferometer) device and a sampling technique allowing both conversion towards high and low frequencies.The involved mixing principle exploits the spectral characteristics of a sampled signal in which replicas of the original spectrum exist at different other frequencies. Basing the frequency conversion on a sampling technique gives two advantages: the photonic mixer configuration is the same for up and down conversions, and the frequency of the local oscillator can be less than the addressed frequency range.The implementation of such a sampling technique needs an optically-controlled high-frequency optical switch. As shown in this work, a SOA-MZI can play this role. Depending on the relative phase between its arms, an interferometric structure (MZI) can transmit or cancel an optical input signal. By locating one SOA in each arm of the MZI structure, the cross-phase modulation that exists inside an SOA is exploited to optically control the optical switch state of the MZI.Controlled by an optical pulse source, this optical switch is able to sample an optical input signal carrying complexmodulated data. Frequency conversions of mono and multi-carrier signals in the range 0.5-39.5 GHz have been successfully achieved. By using a differential configuration of the SOA-MZI, both up and down conversions at bitrates up to 1 Gb/s are reached.
10 citations
Cites background or methods from "OFDM for Optical Communications"
...24: Spectrum of WDM or FDM signal (a) and OFDM signal (b) [143]....
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...The overall OFDM signal is then used to modulate a main radio frequency (RF) carrier [143]....
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...In FDM, there are frequency guard bands between subcarriers, so at the receiver, individual subcarriers are recovered using analog filtering techniques [143]....
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References
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TL;DR: In this article, the authors examined the performance of using multi-element array (MEA) technology to improve the bit-rate of digital wireless communications and showed that with high probability extraordinary capacity is available.
Abstract: This paper is motivated by the need for fundamental understanding of ultimate limits of bandwidth efficient delivery of higher bit-rates in digital wireless communications and to also begin to look into how these limits might be approached. We examine exploitation of multi-element array (MEA) technology, that is processing the spatial dimension (not just the time dimension) to improve wireless capacities in certain applications. Specifically, we present some basic information theory results that promise great advantages of using MEAs in wireless LANs and building to building wireless communication links. We explore the important case when the channel characteristic is not available at the transmitter but the receiver knows (tracks) the characteristic which is subject to Rayleigh fading. Fixing the overall transmitted power, we express the capacity offered by MEA technology and we see how the capacity scales with increasing SNR for a large but practical number, n, of antenna elements at both transmitter and receiver.
We investigate the case of independent Rayleigh faded paths between antenna elements and find that with high probability extraordinary capacity is available. Compared to the baseline n = 1 case, which by Shannon‘s classical formula scales as one more bit/cycle for every 3 dB of signal-to-noise ratio (SNR) increase, remarkably with MEAs, the scaling is almost like n more bits/cycle for each 3 dB increase in SNR. To illustrate how great this capacity is, even for small n, take the cases n = 2, 4 and 16 at an average received SNR of 21 dB. For over 99% of the channels the capacity is about 7, 19 and 88 bits/cycle respectively, while if n = 1 there is only about 1.2 bit/cycle at the 99% level. For say a symbol rate equal to the channel bandwith, since it is the bits/symbol/dimension that is relevant for signal constellations, these higher capacities are not unreasonable. The 19 bits/cycle for n = 4 amounts to 4.75 bits/symbol/dimension while 88 bits/cycle for n = 16 amounts to 5.5 bits/symbol/dimension. Standard approaches such as selection and optimum combining are seen to be deficient when compared to what will ultimately be possible. New codecs need to be invented to realize a hefty portion of the great capacity promised.
10,526 citations
Book•
31 Dec 1999
TL;DR: In this paper, the authors present a comprehensive introduction to OFDM for wireless broadband multimedia communications and provide design guidelines to maximize the benefits of this important new technology, including modulation and coding, synchronization, and channel estimation.
Abstract: From the Book:
The manifestations of the mode of goodness can be experienced when all the gates of the body are illuminated by knowledge
The Bhagavad Gita (14.11)
During the joint supervision of a Master's thesis "The Peak-to-Average Power Ratio of OFDM," of Arnout de Wild from Delft University of Technology, The Netherlands, we realized that there was a shortage of technical information on orthogonal frequency division multiplexing (OFDM) in a single reference. Therefore, we decided to write a comprehensive introduction to OFDM. This is the first book to give a broad treatment to OFDM for mobile multimedia communications. Until now, no such book was available in the market. We have attempted to fill this gap in the literature.
Currently, OFDM is of great interest by the researchers in the Universities and research laboratories all over the world. OFDM has already been accepted for the new wireless local area network standards from IEEE 802.11, High Performance Local Area Network type 2 (HIPERLAN/2) and Mobile Multimedia Access Communication (MMAC) Systems. Also, it is expected to be used for the wireless broadband multimedia communications.
OFDM for Wireless Multimedia Communications is the first book to take a comprehensive look at OFDM, providing the design guidelines one needs to maximize benefits from this important new technology. The book gives engineers a solid base for assessing the performance of wireless OFDM systems. It describes the new OFDM-based wireless LAN standards; examines the basics of direct-sequence and frequency-hopping CDMA, helpful in understanding combinations of OFDM and CDMA. It also looks at applications of OFDM, includingdigital audio and video broadcasting, and wireless ATM. Loaded with essential figures and equations, it is a must-have for practicing communications engineers, researchers, academics, and students of communications technology.
Chapter 1 presents a general introduction to wireless broadband multimedia communication systems (WBMCS), multipath propagation, and the history of OFDM. A part of this chapter is based on the contributions of Luis Correia from the Technical University of Lisbon, Portugal, Anand Raghawa Prasad from Lucent Technologies, and Hiroshi Harada from the Communications Research Laboratory, Ministry of Posts and Telecommunications, Yokosuka, Japan.
Chapters 2 to 5 deal with the basic knowledge of OFDM including modulation and coding, synchronization, and channel estimation, that every post-graduate student as well as practicing engineers must learn. Chapter 2 contains contributions of Rob Kopmeiners from Lucent Technologies on the FFT design.
Chapter 6 describes the peak-to-average power problem, as well as several solutions to it. It is partly based on the contribution of Arnout de Wild.
Basic principles of CDMA are discussed in Chapter 7 to understand multi carrier CDMA and frequency-hopping OFDMA, which are described in Chapters 8 and 9. Chapter 8 is based on the research contributions from Shinsuke Hara from the University of Osaka, Japan, a postdoctoral student at Delft University of Technology during 1995-96, Chapter 9 is based on a UMTS proposal, with main contributions of Ralf Bohnke from Sony, Germany, David Bhatoolaul and Magnus Sandell from Lucent Technologies, Matthias Wahlquist from Telia Research, Sweden, and Jan-Jaap van de Beek from Lulea University, Sweden.
Chapter 10 was written from the viewpoint of top technocrats from industries, government departments, and policy-making bodies. It describes several applications of OFDM, with the main focus on wireless ATM in the Magic WAND project, and the new wireless LAN standards for the 5 GHz band from IEEE 802.11, HIPERLAN/2 and MMAC. It is partly based on contributions from Geert Awater from Lucent Technologies, and Masahiro Morikura and Hitoshi Takanashi from NTT in Japan and California, respectively.
We have tried our best to make each chapter quite complete in itself This book will help generate many new research problems and solutions for future mobile multimedia communications. We cannot claim that this book is errorless. Any remarks to improve the text and correct any errors would be highly appreciated.
4,020 citations
TL;DR: The general technique of parallel transmission on many carriers, called multicarrier modulation (MCM), is explained, and the performance that can be achieved on an undistorted channel and algorithms for achieving that performance are discussed.
Abstract: The general technique of parallel transmission on many carriers, called multicarrier modulation (MCM), is explained. The performance that can be achieved on an undistorted channel and algorithms for achieving that performance are discussed. Ways of dealing with channel impairments and of improving the performance through coding are described, and implementation methods are considered. Duplex operation of MCM and the possible use of this on the general switched telephone network are examined. >
3,995 citations
"OFDM for Optical Communications" refers background in this paper
...While many details of OFDM systems are very complex, the basic concept of OFDM is quite simple [4]–[7]....
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Book•
31 Aug 1994TL;DR: The use of infrared radiation as a medium for high-speed short-range wireless digital communication, and several modification formats, including on-off keying (OOK), pulse-position modulation (PPM), and subcarrier modulation, are discussed.
Abstract: The use of infrared radiation as a medium for high-speed short-range wireless digital communication is discussed. Available infrared links and local-area networks are described. Advantages and drawbacks of the infrared medium are compared to those of radio and microwave media. The physical characteristics of infrared channels using intensity modulation with direct detection (IM/DD) are presented including path losses and multipath responses. Natural and artificial ambient infrared noise sources are characterized. Strategies for designs of transmitter and receivers that maximize link signal-to-noise ratio (SNR) are described. Several modification formats are discussed in detail, including on-off keying (OOK) pulse-position modulation (PPM), and subcarrier modulation. The performance of these techniques in the presence of multipath distortion is quantified. Techniques for multiplexing the transmissions of different users are reviewed. The performance of an experimental 50-Mb/s on-off-keyed diffuse infrared link is described.
2,972 citations
"OFDM for Optical Communications" refers background in this paper
...In [30], Kahn and Barry explain why the many optical modes that are present at the receiver result in optical wireless systems being linear in intensity....
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TL;DR: The analysis and simulation of a technique for combating the effects of multipath propagation and cochannel interference on a narrow-band digital mobile channel using the discrete Fourier transform to orthogonally frequency multiplex many narrow subchannels, each signaling at a very low rate, into one high-rate channel is discussed.
Abstract: This paper discusses the analysis and simulation of a technique for combating the effects of multipath propagation and cochannel interference on a narrow-band digital mobile channel. This system uses the discrete Fourier transform to orthogonally frequency multiplex many narrow subchannels, each signaling at a very low rate, into one high-rate channel. When this technique is used with pilot-based correction, the effects of flat Rayleigh fading can be reduced significantly. An improvement in signal-to-interference ratio of 6 dB can be obtained over the bursty Rayleigh channel. In addition, with each subchannel signaling at a low rate, this technique can provide added protection against delay spread. To enhance the behavior of the technique in a heavily frequency-selective environment, interpolated pilots are used. A frequency offset reference scheme is employed for the pilots to improve protection against cochannel interference.
2,627 citations
"OFDM for Optical Communications" refers background in this paper
...Cimini of Bell Labs published a paper on OFDM for mobile communications in 1985 [14], while in 1987, Lassalle and Alard, [15] based in France considered the use of OFDM for radio broadcasting and noted the importance of combining forward error correction (FEC) with OFDM....
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