TY - JOUR

T1 - Data-aided Iterative Algorithms for Linearizing IM/DD Optical Transmission Systems

AU - Hu, Shaohua

AU - Zhang, Jing

AU - Tang, Jianming

AU - Jin, Wei

AU - Giddings, Roger

AU - Qiu, Kun

PY - 2021/5/1

Y1 - 2021/5/1

N2 - —DSP-enhanced intensity-modulation direct-detection(IM/DD) systems can support up to 56 Gb/s over 100 km signaltransmissions at C-band. To achieve higher data rates and longertransmission distances, we propose data-aided iterative algorithm(DIA) and decision-directed DIA (DD-DIA) to digitally mitigatesignal-signal beating interference (SSBI) without requiring anymodifications to physical layer structures. DIA utilizes pilotsymbols with uniformly spaced insertions to relax the modifiedGerchberg-Saxton (G-S) algorithms that suffer from the localoptimum problem. To further improve the symbol error rate(SER) performance and convergence speed, DD-DIA introduces adecision process to generate pseudo-pilots. We numericallycompare DIA with other algorithms and find that DIA canrecover signals subject to large fiber dispersions corresponding towhich conventional IA and Volterra filter (VF) fail, while DD-DIAsignificantly accelerates the convergence speed and improves thereconstruction performance compared with DIA, it can support100-Gb/s PAM4 over 400-km IM/DD transmissions within just 50iterations. Two orders of magnitude reductions in SER isobserved for 100 Gb/s PAM4 signal transmission over 100-kmSSMFs. Compared with conventional IA, the proposed techniqueshave higher convergence speeds, better global optimum featuresand large tolerances to physical model errors. In particular,DD-DIA results in larger optical signal-to-noise ratio (OSNR)/received optical power (ROP) improvement, higher transmissioncapacities and less computational complexity. DD-DIA is apromising algorithm for efficiently reconstructing 2-dimensionaloptical field for conventional IM/DD optical transmission systems.Index Terms—Optical communication, digital signalprocessing, IM/DD system, field reconstruction.

AB - —DSP-enhanced intensity-modulation direct-detection(IM/DD) systems can support up to 56 Gb/s over 100 km signaltransmissions at C-band. To achieve higher data rates and longertransmission distances, we propose data-aided iterative algorithm(DIA) and decision-directed DIA (DD-DIA) to digitally mitigatesignal-signal beating interference (SSBI) without requiring anymodifications to physical layer structures. DIA utilizes pilotsymbols with uniformly spaced insertions to relax the modifiedGerchberg-Saxton (G-S) algorithms that suffer from the localoptimum problem. To further improve the symbol error rate(SER) performance and convergence speed, DD-DIA introduces adecision process to generate pseudo-pilots. We numericallycompare DIA with other algorithms and find that DIA canrecover signals subject to large fiber dispersions corresponding towhich conventional IA and Volterra filter (VF) fail, while DD-DIAsignificantly accelerates the convergence speed and improves thereconstruction performance compared with DIA, it can support100-Gb/s PAM4 over 400-km IM/DD transmissions within just 50iterations. Two orders of magnitude reductions in SER isobserved for 100 Gb/s PAM4 signal transmission over 100-kmSSMFs. Compared with conventional IA, the proposed techniqueshave higher convergence speeds, better global optimum featuresand large tolerances to physical model errors. In particular,DD-DIA results in larger optical signal-to-noise ratio (OSNR)/received optical power (ROP) improvement, higher transmissioncapacities and less computational complexity. DD-DIA is apromising algorithm for efficiently reconstructing 2-dimensionaloptical field for conventional IM/DD optical transmission systems.Index Terms—Optical communication, digital signalprocessing, IM/DD system, field reconstruction.

KW - Adaptive optics

KW - DD system

KW - Digital signal processing

KW - IM

KW - Optical communication

KW - Optical fibers

KW - Optical filters

KW - Optical modulation

KW - Parameter estimation

KW - Physical layer

KW - Signal processing algorithms

KW - field reconstruction

U2 - 10.1109/JLT.2021.3063689

DO - 10.1109/JLT.2021.3063689

M3 - Article

VL - 39

SP - 2864

EP - 2872

JO - Journal of Lightwave Technology

JF - Journal of Lightwave Technology

SN - 0733-8724

IS - 9

ER -