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William Shieh - One of the best experts on this subject based on the ideXlab platform.

  • High Spectral Efficiency Coherent Optical OFDM
    High Spectral Density Optical Communication Technologies, 2010
    Co-Authors: William Shieh
    Abstract:

    OFDM has quickly gained its attraction in optical communications that are evolving toward software-enhanced optical transmissions. Coherent optical OFDM (CO-OFDM) takes advantage of software capabilities of electronic digital signal processing (DSP) to perform sophisticated operations and has demonstrated its easiness of realizing High Spectral Efficiency and combating various distortions at the same time. This chapter presents the signal processing of coherent optical MIMO-OFDM and elucidates its capability. In the first part, centered on High Spectral Efficiency, CO-OFDM is investigated to implement High-order QAM modulation. In the second part, orthogonal-band-multiplexed OFDM (OBM-OFDM) is discussed to alleviate the analog bandwidth requirement of DACs/ADCs and to eliminate the frequency guard band between the optical channels. With the theoretical analysis and experimental demonstrations in both parts, CO-OFDM presents itself as an attractive candidate for High Spectral Efficiency optical transmissions.

  • experimental demonstration and numerical simulation of 107 gb s High Spectral Efficiency coherent optical ofdm
    Journal of Lightwave Technology, 2009
    Co-Authors: Qi Yang, Yan Tang, William Shieh
    Abstract:

    Orthogonal frequency-division multiplexing (OFDM) is a multicarrier modulation format in which the data are transmitted with a set of orthogonal subcarriers. Recently, this modulation format has been actively explored in the field of optical communications to take advantages of its High Spectral Efficiency and resilience to chromatic and polarization dispersion. However, to realize the optical OFDM at 100 Gb/s and beyond requires extremely High electronic bandwidth for the electronic signal processing elements. In this paper, we investigate orthogonal-band-multiplexed OFDM (OBM-OFDM) as a suitable modulation and multiplexing scheme for achieving bandwidth scalable and Spectral efficient long-haul transmission systems. The OBM-OFDM signal can be implemented in either RF domain, or optical domain, or a combination of both domains. Using the scheme of OBM-OFDM, we show the successful transmission of 107 Gb/s data rate over 1000-km standard single-mode fiber (SSMF) without optical dispersion compensation and without Raman amplification. The demonstrated OBM-OFDM system is realized in optical domain which employs 2times2 MIMO-OFDM signal processing and achieves High optical Spectral Efficiency of 3.3 bit/s/Hz using 4-QAM encoding. Additionally, we perform numerical simulation of 107-Gb/s CO-OFDM transmission for both single-channel and wavelength-division-multiplexed (WDM) systems. We find that the Q -factor of OBM-OFDM measured using uniform filling of OFDM subbands is in fact more conservative, in particular, is 1.2 dB and 0.4 dB lower than using random filling for single-channel and WDM systems, respectively.

  • experimental demonstration and numerical simulation of 107 gb s High Spectral Efficiency coherent optical ofdm
    OFC NFOEC 2008, 2009
    Co-Authors: Qi Yang, Yan Tang, William Shieh
    Abstract:

    Orthogonal frequency-division multiplexing (OFDM) is a multicarrier modulation format in which the data are transmitted with a set of orthogonal subcarriers. Recently, this modulation format has been actively explored in the field of optical communications to take advantages of its High Spectral Efficiency and resilience to chromatic and polarization dispersion. However, to realize the optical OFDM at 100 Gb/s and beyond requires extremely High electronic bandwidth for the electronic signal processing elements. In this paper, we investigate orthogonal-band-multiplexed OFDM (OBM-OFDM) as a suitable modulation and multiplexing scheme for achieving bandwidth scalable and Spectral efficient long-haul transmission systems. The OBM-OFDM signal can be implemented in either RF domain, or optical domain, or a combination of both domains. Using the scheme of OBM-OFDM, we show the successful transmission of 107 Gb/s data rate over 1000-km standard single-mode fiber (SSMF) without optical dispersion compensation and without Raman amplification. The demonstrated OBM-OFDM system is realized in optical domain which employs 2 × 2 MIMO-OFDM signal processing and achieves High optical Spectral Efficiency of 3.3 bit/s/Hz using 4-QAM encoding. Additionally, we perform numerical simulation of 107-Gb/s CO-OFDM transmission for both single-channel and wavelength-division-multiplexed (WDM) systems. We find that the Q-factor of OBM-OFDM measured using uniform filling of OFDM subbands is in fact more conservative, in particular, is 1.2 dB and 0.4 dB lower than using random filling for single-channel and WDM systems, respectively.

  • High-speed and High Spectral Efficiency coherent optical OFDM
    2008 Digest of the IEEE LEOS Summer Topical Meetings, 2008
    Co-Authors: William Shieh, Qi Yang
    Abstract:

    We show 107 Gb/s CO-OFDM transmission over 1000-km SSMF fiber without optical-dispersion compensation and without Raman amplification. Orthogonal-band-multiplexed-OFDM is proposed to achieve High-speed and High Spectral Efficiency transmission without requiring extremely High DAC/ADC sampling rate.

  • Phase Noise Effects on High Spectral Efficiency Coherent Optical OFDM Transmission
    Journal of Lightwave Technology, 2008
    Co-Authors: William Shieh
    Abstract:

    There are three major advantages for coherent optical orthogonal frequency-division multiplexing (CO-OFDM) transmission using digital signal processing. First, coherent detection is realized by digital phase estimation without the need for optical phase-locked loop. Second, OFDM modulation and demodulation are realized by the well-established computation-efficient fast Fourier transform (FFT) and inverse FFT. Third, adaptive data rates can be supported as different quadrature amplitude modulation (QAM) constellations are software-defined, without any hardware change in transmitter and receiver. However, it is well-known that coherent detection, OFDM, and QAM are all susceptible to phase noise. In this paper, theoretical, numerical, and experimental investigations are carried out for phase noise effects on High Spectral Efficiency CO-OFDM transmission. A transmission model in the presence of phase noise is presented. By using simulation, the bit error rate floors from finite laser linewidth are presented for CO-OFDM systems with High-order QAM constellations. In the experiments, the phase noise effects from both laser linewidth and nonlinear fiber transmission are investigated. The fiber nonlinearity mitigation based on receiver digital signal processing is also discussed.

Xiang Liu - One of the best experts on this subject based on the ideXlab platform.

  • OFDM-based High Spectral Efficiency transmission
    Asia Communications and Photonics Conference, 2012
    Co-Authors: Xiang Liu, S. Chandrasekhar
    Abstract:

    We review recent advances in the generation, detection, and transmission of High Spectral Efficiency optical superchannels that utilize orthogonal-frequency-division-multiplexing for optical carrier modulation and/or carrier multiplexing. System implications brought by these superchannels are also discussed.

  • High Spectral-Efficiency Transmission Techniques for Systems Beyond 100 Gb/s
    Advanced Photonics, 2011
    Co-Authors: Xiang Liu, S. Chandrasekhar
    Abstract:

    We review recent progress on High Spectral-Efficiency optical transmission with per-channel data rates beyond 100 Gb/s. Enabling technologies such as High-level QAM modulation and multiband superchannel transmission are discussed.

  • High Spectral-Efficiency DWDM transmission with mixed data rates and signal formats
    Optical Transmission Switching and Subsystems VI, 2008
    Co-Authors: Xiang Liu, S. Chandrasekhar
    Abstract:

    Optical fiber transport networks have been evolving rapidly to meet the demands of today's telecommunications by providing unprecedented transmission capacity and reach. In dense wavelength-division-multiplexing (DWDM) transport systems, 10-Gb/s channels are widely deployed, and 40-Gb/s channels are starting to be added in the same systems. In the foreseeable future, 100-Gb/s channels are expected to be carried. The realization of such High Spectral- Efficiency DWDM systems with mixed data rates and signal formats presents several technical challenges. In this paper, we review these challenges and discuss promising technologies that may potentially address these challenges.

  • A hybrid electroabsorption modulator device for generation of High Spectral-Efficiency optical modulation formats.
    Optics express, 2008
    Co-Authors: Inuk Kang, Xiang Liu, S. Chandrasekhar, Lawrence L. Buhl, P.g. Bernasconi, Clinton Randy Giles, Christophe Kazmierski, Nicolas Dupuis, Jean Decobert, F. Alexandre
    Abstract:

    We report a novel hybrid integrated optic device consisting of AlGaInAs/InP electroabsorption modulators and a four-arm silica-on-silicon planar lightwave circuit optical interferometer. The device is designed for generation of High Spectral Efficiency optical modulation formats. We demonstrate generation of 21.4 Gb/s quadrature phase shift keyed optical signals with electrical data drives of 2Vpp amplitudes, achieving a bit error rate of 10-9 with the required optical signal to noise ratio of ~18 dB in a 0.1 nm resolution bandwidth.

  • Differential phase-shift keying for High Spectral Efficiency optical transmissions
    IEEE Journal of Selected Topics in Quantum Electronics, 2004
    Co-Authors: Xiang Liu, Xing Wei
    Abstract:

    Differential phase-shift keying (DPSK) has attracted significant attentions in research and development during the last several years. An overview of DPSK for High Spectral Efficiency optical transmission is presented in this paper. The advantages of DPSK in terms of receiver sensitivity and tolerance to fiber nonlinearity will be discussed in detail. A simplified method for estimating the performance of phase-shift keying in numerical simulations is explained. Results of experimental and numerical investigations of several phase shift keying formats, including polarization division multiplexing and multilevel encoding, will be reviewed. Finally, methods for further enhancing performance of phase-shift keying in long-haul transmissions, specifically the compensation of nonlinear phase jitter, are presented.

Xiang Zhou - One of the best experts on this subject based on the ideXlab platform.

  • Comprar Enabling Technologies For High Spectral-Efficiency Coherent Optical Communication Networks | Xiang Zhou | 9781118714768 | Wiley
    2016
    Co-Authors: Xiang Zhou
    Abstract:

    Tienda online donde Comprar Enabling Technologies For High Spectral-Efficiency Coherent Optical Communication Networks al precio 123,67 € de Xiang Zhou, tienda de Libros de Medicina, Libros de Oftalmologia y Optica - Optica

  • DSP for High Spectral Efficiency 400G transmission
    39th European Conference and Exhibition on Optical Communication (ECOC 2013), 2013
    Co-Authors: Xiang Zhou
    Abstract:

    This paper presents an overview of several advanced digital signal processing (DSP)enabled technologies recently demonstrated for High Spectral Efficiency (SE) 400Gb/s-class transmission, including the SE-adaptable time-domain hybrid QAM, transmitter-side digital Spectral shaping, and training-assisted carrier phase recovery.

  • Erratum [regarding "High Spectral Efficiency 400 Gb/s Transmission Using PDM Time-Domain Hybrid 32-64 QAM and Training-Assisted Carrier Recovery"]
    Journal of Lightwave Technology, 2013
    Co-Authors: Xiang Zhou, Lynn E. Nelson, Peter Magill, Rejoy Isaac, Benyuan Zhu, David W. Peckham, Peter Ingo Borel, K. Carlson
    Abstract:

    The following article "High Spectral Efficiency 400 Gb/s Transmission Using PDM Time-Domain Hybrid 32-64 QAM and Training-Assisted Carrier Recovery" by High Spectral Efficiency 400 Gb/s Transmission, et al. [ibid., vol. 31, no. 7, pp. 999-1005, Apr. 2013] was inadvertently omitted from the Special Issue on Optical Fiber Communications/National Fiber Optics Engineers Conference 2012: High Spectral Efficiency 400 Gb/s Transmission Using PDM Time-Domain Hybrid 32-64 QAM and Training-Assisted Carrier Recovery.

  • Multi-Level, Multi-Dimensional Coding for High-Speed and High-Spectral-Efficiency Optical Transmission
    Journal of Lightwave Technology, 2009
    Co-Authors: Xiang Zhou
    Abstract:

    We review and study several single carrier based multi-level and multi-dimensional coding (ML-MDC) technologies recently demonstrated for Spectrally-efficient 100-Gb/s transmission. These include 16-ary PDM-QPSK, 64-ary PDM-8PSK, 64-ary PDM-8QAM as well as 256-ary PDM-16 QAM. We show that High-speed QPSK, 8PSK, 8QAM, and 16QAM can all be generated using commercially available optical modulators using only binary electrical drive signals through novel synthesis methods, and that all of these modulation formats can be detected using a universal receiver front-end and digital coherent detection. We show that the constant modulus algorithm (CMA), which is Highly effective for blind polarization recovery of PDM-QPSK and PDM-8PSK signals, is much less effective for PDM-8QAM and PDM-16 QAM. We then present a recently proposed, cascaded multi-modulus algorithm for these cases. In addition to the DSP algorithms used for constellation recovery, we also describe a DSP algorithm to improve the performance of a coherent receiver using single-ended photo-detection. The system impact of ASE noise, laser phase noise, narrowband optical filtering and fiber nonlinear effects has been investigated. For High-level modulation formats using full receiver-side digital compensation, it is shown that the requirement on LO phase noise is more stringent than the signal laser. We also show that RZ pulse shaping significantly improves filter- and fiber-nonlinear tolerance. Finally we present three High-Spectral-Efficiency and High-speed DWDM transmission experiments implementing these ML-MDC technologies.

Zhixing Yang - One of the best experts on this subject based on the ideXlab platform.

  • Time-Frequency Training OFDM with High Spectral Efficiency and Reliable Performance in High Speed Environments
    IEEE Journal on Selected Areas in Communications, 2012
    Co-Authors: Linglong Dai, Zhaocheng Wang, Zhixing Yang
    Abstract:

    Orthogonal frequency division multiplexing (OFDM) is widely recognized as the key technology for the next generation broadband wireless communication (BWC) systems. Besides High Spectral Efficiency, reliable performance over fast fading channels is becoming more and more important for OFDM-based BWC systems, especially when High speed cars, trains and subways are playing an increasingly indispensable role in our daily life. The time domain synchronous OFDM (TDS-OFDM) has Higher Spectral Efficiency than the standard cyclic prefix OFDM (CP-OFDM), but suffers from severe performance loss over High speed mobile channels since the required iterative interference cancellation between the training sequence (TS) and the OFDM data block. In this paper, a fundamentally distinct OFDM-based transmission scheme called time-frequency training OFDM (TFT-OFDM) is proposed, whereby every TFT-OFDM symbol has training information both in the time and frequency domains. Unlike TDS-OFDM or CP-OFDM where the channel estimation is solely dependent on either time-domain TS or frequency-domain pilots, the joint time-frequency channel estimation for TFT-OFDM utilizes the time-domain TS without interference cancellation to merely acquire the path delay information of the channel, while the path coefficients are estimated by using the frequency-domain grouped pilots. The redundant grouped pilots only occupy about 3% of the total subcarriers, thus TFT-OFDM still has much Higher Spectral Efficiency than CP-OFDM by about 8.5% in typical applications. Simulation results also demonstrate that TFT-OFDM outperforms CP-OFDM and TDS-OFDM in High speed mobile environments.

Peter J Winzer - One of the best experts on this subject based on the ideXlab platform.

  • High Spectral Efficiency Optical Transmission with Probabilistic Constellation Shaping
    2018 23rd Opto-Electronics and Communications Conference (OECC), 2018
    Co-Authors: Junho Cho, S. Chandrasekhar, Gregory Raybon, Xi Chen, Samuel L. I. Olsson, Peter J Winzer
    Abstract:

    This paper reviews recent progress in High Spectral Efficiency optical transmission using probabilistic constellation shaping (PCS), and discusses various aspects of PCS from theoretic and practical benefits to performance optimization.

  • High Spectral Efficiency optical modulation formats
    Journal of Lightwave Technology, 2012
    Co-Authors: Peter J Winzer
    Abstract:

    As 100-Gb/s coherent systems based on polarization- division multiplexed quadrature phase shift keying (PDM-QPSK), with aggregate wavelength-division multiplexed (WDM) capacities close to 10 Tb/s, are getting widely deployed, the use of High-Spectral-Efficiency quadrature amplitude modulation (QAM) to increase both per-channel interface rates and aggregate WDM capacities is the next evolutionary step. In this paper we review High-Spectral-Efficiency optical modulation formats for use in digital coherent systems. We look at fundamental as well as at technological scaling trends and Highlight important trade-offs pertaining to the design and performance of coherent Higher-order QAM transponders.

  • Optical Equalization of 42.7-Gbaud Band-Limited NRZ-DQPSK Signals for High-Spectral-Efficiency Transmission
    OFC NFOEC 2007 - 2007 Conference on Optical Fiber Communication and the National Fiber Optic Engineers Conference, 2007
    Co-Authors: Alan H. Gnauck, Peter J Winzer, Christopher R. Doerr, S. Cabot, M.a. Cappuzzo, E. Chen, A. Wong-foy, L.t. Gomez, M.t. Santo, Tetsuya Kawanishi
    Abstract:

    We demonstrate the use of an optical equalizer to allow a 42.7-Gbaud (85.4-Gb/s) NRZ-DQPSK signal to tolerate the narrow optical filtering required in High-Spectral-Efficiency systems. The equalizer passbands are repetitive, enabling equalization of multiple channels.