1.
Hu, Shaohua; Wang, Shen; Tang, Jianming; Zhang, Jing; Xu, Zhaopeng; Jin, Wei; Liu, Lulu; Zhou, Jiahao; Yi, Xingwen; Xu, Bo; Qiu, Kun
In: Optics Express, vol. 33, no. 15, pp. 31129–31138, 2025, ISSN: 1094-4087, (Publisher: Optica Publishing Group).
Abstract | Links | BibTeX | Tags: Modulation, Numerical simulation, Optical systems, Signal processing, Single mode fibers, Variable optical attenuators
@article{hu_decoupled_2025,
title = {Decoupled digital filtering-enabled simplification and fast convergence of IM/DD system linearization algorithms for strong band-limited power fading channels},
author = {Shaohua Hu and Shen Wang and Jianming Tang and Jing Zhang and Zhaopeng Xu and Wei Jin and Lulu Liu and Jiahao Zhou and Xingwen Yi and Bo Xu and Kun Qiu},
url = {https://opg.optica.org/oe/abstract.cfm?uri=oe-33-15-31129},
doi = {10.1364/OE.565790},
issn = {1094-4087},
year = {2025},
date = {2025-07-01},
urldate = {2025-10-08},
journal = {Optics Express},
volume = {33},
number = {15},
pages = {31129–31138},
publisher = {Optica Publishing Group},
abstract = {Chromatic dispersion limits practically achievable transmission distances of high data-rate intensity modulation and direct detection (IM/DD) optical transmission systems at C-band. Previously reported IM/DD system linearization algorithms can improve their transmission performances, which are, however, sensitive to the band limitation effect. In this paper, for linearizing IM/DD fiber channels with severe power fading and band-limitation, we propose and evaluate numerically and experimentally a decoupled system linearization scheme called equalization-cascaded multi-constraint iterative algorithm (EC-MCIA) using decoupled, channel partial-aware adaptive digital filters and a multiple constraint iteration algorithm. Compared with the previously reported hybrid MCIA with an embedded filter pair, the EC-MCIA can reduce the complexity and improve the linearization performance. In simulations, we observe two orders of magnitude bit-error-rate (BER) reductions for 100-Gb/s@100-km pulse amplitude modulation (PAM4) transmissions. We also experimentally demonstrate C-band 224 Gbit/s PAM4 transmissions over 25-km standard single mode fibers (SSMF). Experimental results show that the EC-MCIA achieves BERs lower than the 20% forward error correction (FEC) limit and outperforms the hybrid MCIA by nearly an order of magnitude. The required number of taps for the decoupled linear filter is only 15.},
note = {Publisher: Optica Publishing Group},
keywords = {Modulation, Numerical simulation, Optical systems, Signal processing, Single mode fibers, Variable optical attenuators},
pubstate = {published},
tppubtype = {article}
}
Chromatic dispersion limits practically achievable transmission distances of high data-rate intensity modulation and direct detection (IM/DD) optical transmission systems at C-band. Previously reported IM/DD system linearization algorithms can improve their transmission performances, which are, however, sensitive to the band limitation effect. In this paper, for linearizing IM/DD fiber channels with severe power fading and band-limitation, we propose and evaluate numerically and experimentally a decoupled system linearization scheme called equalization-cascaded multi-constraint iterative algorithm (EC-MCIA) using decoupled, channel partial-aware adaptive digital filters and a multiple constraint iteration algorithm. Compared with the previously reported hybrid MCIA with an embedded filter pair, the EC-MCIA can reduce the complexity and improve the linearization performance. In simulations, we observe two orders of magnitude bit-error-rate (BER) reductions for 100-Gb/s@100-km pulse amplitude modulation (PAM4) transmissions. We also experimentally demonstrate C-band 224 Gbit/s PAM4 transmissions over 25-km standard single mode fibers (SSMF). Experimental results show that the EC-MCIA achieves BERs lower than the 20% forward error correction (FEC) limit and outperforms the hybrid MCIA by nearly an order of magnitude. The required number of taps for the decoupled linear filter is only 15.
2.
Hu, Shaohua; Wang, Shen; Tang, Jianming; Zhang, Jing; Xu, Zhaopeng; Jin, Wei; Liu, Lulu; Zhou, Jiahao; Yi, Xingwen; Xu, Bo; Qiu, Kun
In: Optics Express, vol. 33, no. 15, pp. 31129–31138, 2025, ISSN: 1094-4087, (Publisher: Optica Publishing Group).
Abstract | Links | BibTeX | Tags: Modulation, Numerical simulation, Optical systems, Signal processing, Single mode fibers, Variable optical attenuators
@article{hu_decoupled_2025-1,
title = {Decoupled digital filtering-enabled simplification and fast convergence of IM/DD system linearization algorithms for strong band-limited power fading channels},
author = {Shaohua Hu and Shen Wang and Jianming Tang and Jing Zhang and Zhaopeng Xu and Wei Jin and Lulu Liu and Jiahao Zhou and Xingwen Yi and Bo Xu and Kun Qiu},
url = {https://opg.optica.org/oe/abstract.cfm?uri=oe-33-15-31129},
doi = {10.1364/OE.565790},
issn = {1094-4087},
year = {2025},
date = {2025-07-01},
urldate = {2025-10-08},
journal = {Optics Express},
volume = {33},
number = {15},
pages = {31129–31138},
publisher = {Optica Publishing Group},
abstract = {Chromatic dispersion limits practically achievable transmission distances of high data-rate intensity modulation and direct detection (IM/DD) optical transmission systems at C-band. Previously reported IM/DD system linearization algorithms can improve their transmission performances, which are, however, sensitive to the band limitation effect. In this paper, for linearizing IM/DD fiber channels with severe power fading and band-limitation, we propose and evaluate numerically and experimentally a decoupled system linearization scheme called equalization-cascaded multi-constraint iterative algorithm (EC-MCIA) using decoupled, channel partial-aware adaptive digital filters and a multiple constraint iteration algorithm. Compared with the previously reported hybrid MCIA with an embedded filter pair, the EC-MCIA can reduce the complexity and improve the linearization performance. In simulations, we observe two orders of magnitude bit-error-rate (BER) reductions for 100-Gb/s@100-km pulse amplitude modulation (PAM4) transmissions. We also experimentally demonstrate C-band 224 Gbit/s PAM4 transmissions over 25-km standard single mode fibers (SSMF). Experimental results show that the EC-MCIA achieves BERs lower than the 20% forward error correction (FEC) limit and outperforms the hybrid MCIA by nearly an order of magnitude. The required number of taps for the decoupled linear filter is only 15.},
note = {Publisher: Optica Publishing Group},
keywords = {Modulation, Numerical simulation, Optical systems, Signal processing, Single mode fibers, Variable optical attenuators},
pubstate = {published},
tppubtype = {article}
}
Chromatic dispersion limits practically achievable transmission distances of high data-rate intensity modulation and direct detection (IM/DD) optical transmission systems at C-band. Previously reported IM/DD system linearization algorithms can improve their transmission performances, which are, however, sensitive to the band limitation effect. In this paper, for linearizing IM/DD fiber channels with severe power fading and band-limitation, we propose and evaluate numerically and experimentally a decoupled system linearization scheme called equalization-cascaded multi-constraint iterative algorithm (EC-MCIA) using decoupled, channel partial-aware adaptive digital filters and a multiple constraint iteration algorithm. Compared with the previously reported hybrid MCIA with an embedded filter pair, the EC-MCIA can reduce the complexity and improve the linearization performance. In simulations, we observe two orders of magnitude bit-error-rate (BER) reductions for 100-Gb/s@100-km pulse amplitude modulation (PAM4) transmissions. We also experimentally demonstrate C-band 224 Gbit/s PAM4 transmissions over 25-km standard single mode fibers (SSMF). Experimental results show that the EC-MCIA achieves BERs lower than the 20% forward error correction (FEC) limit and outperforms the hybrid MCIA by nearly an order of magnitude. The required number of taps for the decoupled linear filter is only 15.
3.
Vallejo, Luis; Gonem, Omaro Fawzi Abdelhamid; Jin, Wei; Giddings, Roger Philip; Chen, Lin; Huang, Yi; Yi, Xingwen; Faruk, Md Saifuddin; Tang, Jianming
Seamlessly Converged Fiber-Wireless Access Networks With Dynamic Sub-Wavelength Switching and Tunable Photonic mmWave Generation Journal Article
In: Journal of Lightwave Technology, vol. 43, no. 6, pp. 2624–2635, 2025, (Publisher: IEEE).
Abstract | Links | BibTeX | Tags: Frequency division multiplexing, Optical signals, Optical switching devices, Signal processing, Signal transmission, Variable optical attenuators
@article{vallejo_seamlessly_2025,
title = {Seamlessly Converged Fiber-Wireless Access Networks With Dynamic Sub-Wavelength Switching and Tunable Photonic mmWave Generation},
author = {Luis Vallejo and Omaro Fawzi Abdelhamid Gonem and Wei Jin and Roger Philip Giddings and Lin Chen and Yi Huang and Xingwen Yi and Md Saifuddin Faruk and Jianming Tang},
url = {https://opg.optica.org/jlt/abstract.cfm?uri=jlt-43-6-2624},
year = {2025},
date = {2025-03-01},
urldate = {2025-10-08},
journal = {Journal of Lightwave Technology},
volume = {43},
number = {6},
pages = {2624–2635},
publisher = {IEEE},
abstract = {For implementing next-generation radio access networks (NG-RANs) supporting services/applications in the beyond-5G (B5G) era, seamless fiber-wireless network convergence is vital for enabling heterogeneous signals of various characteristics to continuously flow between the optical and electrical domains, i.e., the baseband unit (BBU) and user equipment (UE), without optical-electrical-optical (O-E-O) conversions or digital signal processing (DSP) at any intermediate nodes. To address such challenges, this paper proposes and experimentally demonstrates, for the first time, a cost-effective fiber-wireless converged flexible and dynamic access network based on intensity modulation and direct detection (IM-DD). The demonstrated network utilizes O-E-O conversion-free Soft-reconfigurable optical add/drop multiplexers (Soft-ROADMs) at remote nodes to dynamically establish connections between the BBU and the remote radio heads (RRHs) at the sub-wavelength level. In addition, free-running laser-enabled photonic millimeter-wave (mmWave) signal generation and passive electrical envelope detector-enabled mmWave down-conversion are also used, respectively, at the RRHs and UEs to achieve mmWave frequency tunability and adaptive wireless network coverage. The network performance and optimum network configuration are experimentally explored extensively in a fiber-wireless converged access network with 3 × 1.333 Gbps dynamic BBU-UE connections over a 10 km IM-DD fiber link and a 5 m, 38 GHz mmWave wireless link. The results show that wide mmWave frequency tuning ranges and adaptive mmWave coverages are achievable by just adjusting the RRH-laser frequency and output powers.},
note = {Publisher: IEEE},
keywords = {Frequency division multiplexing, Optical signals, Optical switching devices, Signal processing, Signal transmission, Variable optical attenuators},
pubstate = {published},
tppubtype = {article}
}
For implementing next-generation radio access networks (NG-RANs) supporting services/applications in the beyond-5G (B5G) era, seamless fiber-wireless network convergence is vital for enabling heterogeneous signals of various characteristics to continuously flow between the optical and electrical domains, i.e., the baseband unit (BBU) and user equipment (UE), without optical-electrical-optical (O-E-O) conversions or digital signal processing (DSP) at any intermediate nodes. To address such challenges, this paper proposes and experimentally demonstrates, for the first time, a cost-effective fiber-wireless converged flexible and dynamic access network based on intensity modulation and direct detection (IM-DD). The demonstrated network utilizes O-E-O conversion-free Soft-reconfigurable optical add/drop multiplexers (Soft-ROADMs) at remote nodes to dynamically establish connections between the BBU and the remote radio heads (RRHs) at the sub-wavelength level. In addition, free-running laser-enabled photonic millimeter-wave (mmWave) signal generation and passive electrical envelope detector-enabled mmWave down-conversion are also used, respectively, at the RRHs and UEs to achieve mmWave frequency tunability and adaptive wireless network coverage. The network performance and optimum network configuration are experimentally explored extensively in a fiber-wireless converged access network with 3 × 1.333 Gbps dynamic BBU-UE connections over a 10 km IM-DD fiber link and a 5 m, 38 GHz mmWave wireless link. The results show that wide mmWave frequency tuning ranges and adaptive mmWave coverages are achievable by just adjusting the RRH-laser frequency and output powers.