OFDM versus Single-Carrier Transmission for 100 Gbps Optical Communication (original) (raw)
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2012 14th International Conference on Transparent Optical Networks (ICTON), 2012
The performance of coherent dual-polarization multi-band OFDM (DP MB-OFDM) and coherent single-carrier dual-polarization QPSK (DP QPSK) is experimentally compared for 100 Gb/s long-haul transmissions. It is shown that, after transmission over 1000km of DCF-free G.652 fiber line, DP MB-OFDM and DP QPSK have nearly the same performance. Furthermore, it is shown based on numerical simulations that DP MB-OFDM is sensitive to the nonlinear inter-band crosstalk effects such as FWM and XPM.
Optics Express, 2014
A number of critical issues for dual-polarization single-and multi-band optical orthogonal-frequency division multiplexing (DP-SB/MB-OFDM) signals are analyzed in dispersion compensation fiber (DCF)-free long-haul links. For the first time, different DP crosstalk removal techniques are compared, the maximum transmission-reach is investigated, and the impact of subcarrier number and high-level modulation formats are explored thoroughly. It is shown, for a bit-error-rate (BER) of 10 −3 , 2000 km of quaternary phase-shift keying (QPSK) DP-MB-OFDM transmission is feasible. At high launched optical powers (LOP), maximum-likelihood decoding can extend the LOP of 40 Gb/s QPSK DP-SB-OFDM at 2000 km by 1.5 dB compared to zero-forcing. For a 100 Gb/s DP-MB-OFDM system, a high number of subcarriers contribute to improved BER but at the cost of digital signal processing computational complexity, whilst by adapting the cyclic prefix length the BER can be improved for a low number of subcarriers. In addition, when 16-quadrature amplitude modulation (16QAM) is employed the digital-toanalogue/analogue-to-digital converter (DAC/ADC) bandwidth is relaxed with a degraded BER; while the 'circular' 8QAM is slightly superior to its 'rectangular' form. Finally, the transmission of wavelength-division multiplexing DP-MB-OFDM and single-carrier DP-QPSK is experimentally compared for up to 500 Gb/s showing great potential and similar performance at 1000 km DCF-free G.652 line.
High-speed multi-channel long-haul coherent optical transmission system
TELKOMNIKA Telecommunication Computing Electronics and Control, 2022
In this work, high-speed transmission over the long-haul optical channel using orthogonal frequency division multiplexing (OFDM) was investigated. Furthermore, we recommend mixing polarization division multiplexing (PDM) with coherent OFDM (CO-OFDM) and quadrature amplitude modulation (16-QAM) to improve spectral efficiency (SE) while transmitting over a wavelength division multiplexing (WDM) system. An 800 Gb/s WDM PDM-CO-OFDM-16QAM transmission system with various channel spacing of 100 GHz, 50 GHz, and 25 GHz is examined utilizing the OptiSystem (2021) version 18.0 software package over ten spans of 60 km standard single-mode fiber (SSMF). Different channel spacing WDM systems have been compared in terms of performance and SE. The results reveal that the WDM system with 100 GHz channel spacing has a longer transmission range and needs minimal optical signal to noise ratio (OSNR) at the reception. The 25 GHz channel spacing WDM system exceeds the others in terms of SE. Further, the effect of ultra-low loss and large effective area fiber in lowering span loss and nonlinear effects for 25 GHz channel spacing WDM system is investigated. The findings show that the system performance with the new fiber outperforms the SSMF. The acceptable bit error rate (BER) for this study is 0.033 (20% concatenated forward error correction (FEC) threshold).
IEEE Photonics Technology Letters, 2000
In the perspective of smooth capacity upgrades of legacy systems, we experimentally investigate the performance of one 100-Gb/s coherent polarization-division-multiplexed quaternary-phase-shift-keying (PDM-QPSK) channel inserted in a 10-Gb/s ultra-long-haul (ULH) wavelength-division-multiplexing system relying on nonzero dispersion-shifted fibers. The impact of copropagating 10-Gb/s nonreturn-to-zero (NRZ) channels operating ULH distances onto the operational power range of the inserted 100-Gb/s coherent PDM-QPSK channel is analyzed. Moreover, the performance penalties brought by copropagating 10-Gb/s NRZ channels onto 100-Gb/s PDM-QPSK data are also analyzed depending on the number of channels in the multiplex and on the introduction of guardbands between both type of channels.
Coherent Optical 25.8-Gb/s OFDM Transmission Over 4160-km SSMF
Journal of Lightwave Technology, 2000
We discuss coherent optical orthogonal frequency division multiplexing (CO-OFDM) as a suitable modulation technique for long-haul transmission systems. Several design and implementation aspects of a CO-OFDM system are reviewed, but we especially focus on phase noise compensation. As conventional CO-OFDM transmission systems are very sensitive to laser phase noise a novel method to compensate for phase noise is introduced. With the help of this phase noise compensation method we show continuously detectable OFDM transmission at 25.8 Gb/s data rate (20 Gb/s after coding) over 4160-km SSMF without dispersion compensation.
Spectral efficiency and performance improvement of coherent optical transmission system
Indonesian Journal of Electrical Engineering and Computer Science, 2022
This paper presents an orthogonal frequency division multiplexing (OFDM) for a long-haul optical transmission system with high-rate transferability to alleviate dispersion effects. In addition, we suggest combining polarization division multiplexing (PDM) with coherent OFDM (CO-OFDM) to increase spectral efficiency (SE). Based on OptiSystem (2021) version 18.0" software package, a 100 Gbps single-channel PDM-CO-OFDM transmission system is investigated using different modulation formats; bipolar phase keying (BPSK), quadrature phase shift keying (QPSK), Eight-Phase-Shift Keying modulators (8-PSK), and quadrature amplitude modulation (16-QAM). A 60 km span of standard single-mode fiber (SSMF) cable is employed in this investigation. The system's performance and spectral efficiency have been evaluated by comparing against the different modulation schemes. The outcomes that were got show that the BPSK modulation scheme has the longest transmission distance and requires a lesser level of optical signal to noise ratio (OSNR) at the receiver side. Concerning spectral efficiency, 16-QAM outperforms the others. Farther, the impact of employing ultra-low loss and large effective area fiber in reducing loss and nonlinear effects in the optical channel for 16-QAM modulation formats is examined. The result found that the system with advanced fiber has superior performance than the SSMF. The bit error rate (BER) of 0.033 (20% concatenated forward error correction (FEC) threshold) is used as a baseline.
Global Journal of Research In Engineering, 2014
Orthogonal Frequency Division Multiplex (OFDM) is a high-speed transmission technique widely studied in wireless networks. Its potential presents it as an ideal solution for high-speed transmission in optical fiber networks. This study presents the OFDM modulation associated with Offset Quadrature Phase Shift Keying (OQPSK) filtered using a filter banks for an optical transmission at the rate of 10 GB/s over 1600 Km in a single mode fiber (SMF). The simulations are performed in the VPI Photonics software environment. The results show that the filtered OFDM/OQPSK provides better transmission performance than the Classical OFDM/QPSK firstly because it does not require equalization to certain distances; secondly distances are greater than those achieved with the conventional OFDM in similar studies. In this study the bandwidth is maximized because we do not use the cyclic prefix (CP). Moreover the complexity of transmitters and receivers is reduced, which shows OFDM/OQPSK as an effecti...
Bell Labs Technical Journal, 2010
100 Gb/s end-to-end broadband optical solutions are attractive to cope with the increasing demand for capacity. Polarization-division-multiplexed (PDM) quaternary-phase-shift-keying (QPSK) paired with coherent detection has been found to be promising for upgrading optical legacy systems based on 50 GHz wavelength slots thanks to its high spectral efficiency (2 bit/s/Hz) and its tolerance to linear effects. One of the major concerns for the deployment of such a solution is the transmission reach, mainly limited by nonlinear effects. This limitation can be exacerbated over non-zero dispersion shifted fiber (NZDSF) due to low local chromatic dispersion of the transmission fiber. The aim of this paper is first to report on the benefits brought by combining coherent detection techniques with advanced modulation formats as compared to conventional direct detection schemes for optical fiber communications. Digital signal processing paired with coherent detection is described to point out the efficiency of a coherent receiver to combat noise and to mitigate linear impairments. We then report on nonlinear tolerance of 100 Gb/s coherent PDM-QPSK through an 8 Tb/s transmission over a dispersionmanaged link based on low dispersion fibers. © 2010 Alcatel-Lucent.
Optical OFDM for ultra-high capacity long-haul transmission applications
2011
Optical OFDM is a promising modulation format for next generation fiber-optic transmission systems. The main challenges for optical OFDM are its sensitivity to laser phase noise and high PAPR. In this paper the phase noise tolerance is investigated for the two main phase noise compensation algorithms: carrier phase estimation (CPE) and RF-pilot (RFP) compensation. Furthermore, the nonlinear tolerance of OFDM is addressed for SSMF and LEAF, where it is shown that using RFP-based phase noise compensation a nonlinear improvement of up to 1 dB can be obtained.
ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING IN OPTICAL COMMUNICATION SYSTEMS
Concepts Books Publication, 2017
Optical fiber communication has emerged as a high potential substitute for communication methods such as twisted pair and coaxial wire. The main advantage of optical fiber over previous methods is to have higher capacity of data rate transmission. The conventional types of modulation and demodulation technique, which have been used through optical fiber communication system are Wavelength Division Multiplexing (WDM) technique and Dense Wavelength Division Multiplexing (DWDM) technique so far. In this thesis, the Orthogonal Frequency Division Multiplexing (OFDM) is applied through the modulation and demodulation parts due to some advantages over WDM and DWDM to reach to 100 Gbps data transmission. The main advantage of OFDM-optical fiber is that it only needs one optical source to modulate and one optical source to demodulate the signals at transmitter side and receiver side, which results in a reduction of the cost of the system. Also, by using the OFDM, the chromatic dispersion can be eliminated or decreased. The first generation of optical fiber communication uses the Wavelength Division Multiplexing (WDM), which has become very popular. In this technique of modulation, optical carriers are modulated at different wavelengths into a single optical fiber, the Long-Haul WDM transmission system. For example, by using a 160 wavelength division multiplexing (WDM) channels of 85.4-Gb/s, the 25.6 Tb/s data are transmitted over 240 Km fiber on a 50-GHz channel spacing. At this study, RZDQPSK system is used with having 50% duty cycle of return to zero formats. In the study, the Dense Wavelength Division Multiplexing (DWDM) generates 10 Gbps data by injecting −18 𝑑𝐵𝑚 optical power. Also, pulsed seed-light source is used with interferometric noise suppression to increase the performance of system. In another study, the performance of the DWDM system was analyzed. The 38 𝑑𝐵𝑚 optical power was applied into optical network with the system margin up to 8 dB. By using optical filters, the amount of optical noise was decreased and the total system performance was enhanced. Keywords: Dense Wavelength Division Multiplexing (DWDM), Wavelength Division Multiplexing (WDM), Orthogonal Frequency Division Multiplexing (OFDM), Interferometric