Laser & Optoelectronics Progress, Volume. 60, Issue 17, 1700001(2023)
Survey of Signal Recovery Technique in Few-Mode Fiber Communication System with Strong Mode Coupling
Figures & Tables(24)
Fig. 1. Schematic of a typical few-mode fiber communication system with strong mode coupling
Fig. 2. Schematic of a two-mode fiber transmitting LP01 and LP11 modes, two parallel lines represent two modes. (a) Ideal two-mode fiber transmitting two orthogonal modes; (b) a real fiber that has distributed crosstalk
Fig. 3. Schematic of DMD in a few-mode fiber transmitting three modes (LP01, LP11a, and LP11b)
Fig. 4. Schematic of segmentations of few-mode fiber modeling, transmitting
Fig. 7. System structure of a few-mode fiber with strong coupling system based on MIMO TDE[24]
Fig. 8. System bit error rate and optical power mapping[24]. (a) First data set with suboptimal condition, and the filter tap is 120; (b)(c) second data set with optimized coupling condition, the filter taps are 120 and 80, respectively
Fig. 10. Impulse response of the channel. (a) Input channel; (b) target channel; (c) output channel[74]
Fig. 15. BER performance of STC compensating MDL under strong coupling[27]. (a) With STC; (b) with multi-block STC
Fig. 16. U-PIC method compensates MDL experiment. (a) Experimental structure; (b) comparison of transmission distance and spatial multiplicity[70]
Fig. 18. Performance comparison of ML algorithm under different gain differences[32]. (a) 0.5 dB; (b) 1 dB; (c) 2 dB
Table 1. Comparison of three algorithms for taps update
View tableTable 1. Comparison of three algorithms for taps update
Algorithm Convergence speed Performance Complexity LMS Slow Large steady-state error（channel related） Low RLS Fast Small steady-state error（resistant to noise） Middle VRLS Fast Small steady-state error（resistant to noise） High
Table 2. Main research results of transmission experiments using MIMO equalizer in low-mode fiber strongly coupled systems
View tableTable 2. Main research results of transmission experiments using MIMO equalizer in low-mode fiber strongly coupled systems
Year Reference Research institute Core× mode Distance /km Span length /km Data rate（Gb/s/mode/core/λ） MIMO taps and types 2011 Ref.［ 52 ］University of Melbourne 1×2 4.5 4.5 107 — 2011 Ref.［ 53 ］Bell Labs 1×2 40 40 112 9-15 TDE 2011 Ref.［ 54 ］Bell Labs 1×3 10 10 112 20-100 TDE 2011 Ref.［ 24 ］Bell Labs 1×3 33 33 112 80-120 TDE 2011 Ref.［ 55 ］NEC Labs 1×3 50 50 112 301 TDE 2011 Ref.［ 56 ］Bell Labs 1×5 40 40 112 — 2012 Ref.［ 57 ］Bell Labs 1×3 96 96 80 120 TDE 2012 Ref.［ 58 ］NEC Labs 1×3 85 85 112 481 TDE 2012 Ref.［ 59 ］Bell Labs 1×3 1200 30 80 400 TDE 2012 Ref.［ 60 ］Bell Labs 1×3 209 209 80 400 TDE 2012 Ref.［ 61 ］Eindhoven University of Technology 1×3 119 119 256 401 TDE 2012 Ref.［ 62 ］Bell Labs 1×6 130 65 80 400-600 TDE 2013 Ref.［ 63 ］Bell Labs 1×6 177 59 160 800 FDE 2014 Ref.［ 64 ］NEC Labs 1×3 500 50 76 511 TDE 2015 Ref.［ 65 ］Technical University of Munich 1×6 74.17 74.17 27.18 — 2016 Ref.［ 66 ］NTT Network Innovation Laboratories 12×3 527 52.7 80 128 FDE 2017 Ref.［ 67 ］Photonic Network System Laboratory 1×3 3500 70 360 600 FDE 2018 Ref.［ 68 ］Eindhoven University of Technology 1×6 590 59 240 NA FDE 2018 Ref.［ 69 ］NTT Network Innovation Laboratories 1×3 1020 51 60 400 FDE 2019 Ref.［ 70 ］NTT Network Innovation Laboratories 12×3 >3000 52.7 24 600 FDE 2019 Ref.［ 35 ］NTT Network Innovation Laboratories 1×3 6316.8 75.2 96 — 2020 Ref.［ 71 ］NTT Network Innovation Laboratories 1×3 3060 51 192 896 FDE
Table 3. Main Research results of MIMO equalizer algorithms in MDM system
View tableTable 3. Main Research results of MIMO equalizer algorithms in MDM system
Year Research institute Research result Reference 2012 University of Central Florida Propose single-carrier adaptive FDE for MDM transmission；verify and compare performances of both FDE and TDE Ref.［ 25 ］2013 Bell Labs Implement and analyze the complexity of an adaptive FDE for a 12×12 MIMO-SDM transmission system Ref.［ 34 ］2013 University of Louisiana at Lafayette Propose modified MIMO FDE LMS algorithm to improve the convergence speed by 30% Ref.［ 49 ］2014 Eindhoven University of Technology Using an experimental 3-mode dual polarization coherent transmission setup，the convergence time of the MMSE TDE and FDE can be reduced by approximately 50% and 30% Ref.［ 72 ］2018 Juniper Networks Show RLS algorithm in MIMO could improve the convergence speed by 53.7% over conventional frequency domain LMS Ref.［ 73 ］
Table 4. Main research results of MDL compensation in MDM system with STC
View tableTable 4. Main research results of MDL compensation in MDM system with STC
Year Research institute Research result Reference 2015 TELECOM ParisTech Propose space-time（ST）coding as a DSP solution to mitigate MDL in the optical channel Ref.［ 27 ］2016 TELECOM ParisTech Derive an upper bound that yields the design criterion of space-time codes allowing total mitigation of MDL in SDM Ref.［ 81 ］2016 Peking University Propose a STBC with MIMO scheme to mitigate MDL Ref.［ 82 ］2016 TELECOM ParisTech Investigate MIMO techniques to reduce the impact of the MDL and DSP solutions based on TAST Ref.［ 83 ］2016 NTT Network Innovation Laboratories A method is described for applying space-time coding implemented by Hadamard transform to SDM transmission Ref.［ 84 ］2017 TELECOM ParisTech Study a complete transmission scheme，concatenating forward error correction（FEC）and TAST Ref.［ 85 ］2017 University of Louisiana at Lafayette Explore the performance of STBC assisted MIMO scheme for modal dispersion and MDL mitigation in SDM systems Ref.［ 28 ］2017 Xidian University Orthogonal STBC-based SDM transmission system was investigated to test its efficiency in mitigating MDL Ref.［ 77 ］2018 University of Waterloo Propose a new low-complexity，essentially optimal detection algorithm for TAST codes over MMF channels with MDL Ref.［ 86 ］2019 TELECOM ParisTech Analyze the performance of TAST over MMF optic channels with the MDL under the ML and ZF detection schemes Ref.［ 87 ］2019 Xidian University Propose a method can achieve near-optimal solutions and has a low computational complexity in TAST-assist system Ref.［ 88 ］
Table 5. Main research results of MDL compensation in MDM system with IC
View tableTable 5. Main research results of MDL compensation in MDM system with IC
Year Research institute Research result Reference 2017 NTT Network Innovation Laboratories Unreplicated SIC for MDL-impact mitigation is proposed Ref.［ 93 ］2018 NTT Network Innovation Laboratories Analyze the transmission results over 2500 km multicore FMF with unreplicated SIC scheme Ref.［ 94 ］2019 NTT Network Innovation Laboratories Demonstrate the reach of transmission of 6300 km for 3-mode FMF with unreplicated SIC scheme Ref.［ 35 ］2019 NTT Network Innovation Laboratories Achieve 12-core 3-mode multicore FMF transmission over 3000 km with proposed unreplicated PIC scheme Ref.［ 70 ］
Table 6. Comparison of three algorithms for MDL mitigation
View tableTable 6. Comparison of three algorithms for MDL mitigation
Algorithm Complexity Advantage Disadvantage STC Middle High compatibility with other solutions Additional coder and decoder is required IC Low Suboptimal equalizer Bad performance ML High Simple principle High complexity
Tools
Get Citation
Copy Citation Text
Jianyu Long, Bing Zhang, Xiongwei Yang, Jianjun Yu. Survey of Signal Recovery Technique in Few-Mode Fiber Communication System with Strong Mode Coupling[J]. Laser & Optoelectronics Progress, 2023, 60(17): 1700001
Paper Information
Category: Reviews
Received: Oct. 19, 2022
Accepted: Dec. 12, 2022
Published Online: Sep. 1, 2023
The Author Email: Jianjun Yu (jianjun@fudan.edu.cn)
© Copyright 2018-2021 | Chinese Laser Press.
All Rights Reserved 沪ICP备15018463号-20