Optical Power Budget of 25+ Gbps IM/DD PON with Digital Signal Post-Equalization
Applied Sciences 2020
Aleksejs Udalcovs, Toms Salgals, Lu Zhang, Xiaodan Pang, Anders Djupsjöbacka, Sandis Spolītis, Vjačeslavs Bobrovs, Sergei Popov, Oskars Ozolins

While infrastructure providers are expanding their portfolio to offer sustainable solutions for beyond 10 Gbps in the access segment of optical networks, we experimentally compare several modulation format alternatives for future passive optical networks (PONs) aiming to deliver 25+ Gbps net-rates. As promising candidates, we consider the intensity modulation direct detection (IM/DD) schemes such as electrical duobinary (EDB) and 4-level and 8-level pulse amplitude modulations (PAM-4/8). They are more spectrally efficient than the conventional non-return-to-zero on-off-keying (NRZ-OOK) used in current 10G PONs. As we move to higher rates, digital equalization enhances the performance by smoothening the systems imperfection. However, the impact that such equalization has on the optical power budget remains unclear. Therefore, in this article, we fairly compare the optical power budget values of a time division multiplexed PON (TDM-PON) exploiting a linear digital signal equalization at the receiver side. We consider the conventional PON configuration (20 km of single-mode fiber (SMF), 1:N optical power splitting) with IM/DD and net-rates above 25 Gbps. Furthermore, we focus on a downstream transmission imposing the bandwidth limitations of 10G components using a digital filter before the detection. The obtained results show that the use of a digital post-equalization with 43 feed-forward (FF) and 21 feedback (FB) taps can significantly improve the signal quality enabling new alternatives and enhancing the optical power budget.

Atslēgas vārdi
Optical communications, power budget, IMDD, NRZ-OOK, PAM4, PAM8, Equalization, DSP

Udalcovs, A., Salgals, T., Zhang, L., Pang, X., Djupsjöbacka, A., Spolītis, S., Bobrovs, V., Popov, S., Ozolins, O. Optical Power Budget of 25+ Gbps IM/DD PON with Digital Signal Post-Equalization. Applied Sciences, 2020, Vol. 10, No. 17, Article number 6106. ISSN 2076-3417. Pieejams: doi:10.3390/app10176106

Publikācijas valoda
English (en)
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