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Add to EdgeExperimental Comparison of PAM-8 Probabilistic Shaping with Different Gaussian Orders at 200 Gb/s Net Rate in IM/DD System with O-Band TOSA
Jun 14, 2022
For 200Gb/s net rates, cap probabilistic shaped PAM-8 with different Gaussian orders are experimentally compared against uniform PAM-8. In back-to-back and 5km measurements, cap-shaped 85-GBd PAM-8 with Gaussian order of 5 outperforms 71-GBd uniform PAM-8 by up to 2.90dB and 3.80dB in receiver sensitivity, respectively.
Experimental Comparison of Cap and Cup Probabilistically Shaped PAM for O-Band IM/DD Transmission System
May 18, 2022
For 200Gbit/s net rates, uniform PAM-4, 6 and 8 are experimentally compared against probabilistic shaped PAM-8 cap and cup variants. In back-to-back and 20km measurements, cap shaped 80GBd PAM-8 outperforms 72GBd PAM-8 and 83GBd PAM-6 by up to 3.50dB and 0.8dB in receiver sensitivity, respectively
* Originally published in ECOC-2021. We have updated Figure 3. The change also affects the overall outcome. In contrast to the published version, compared to uniform PAM-8 72 GBd, PS-PAM-8 80 GBd performance is updated to 3.50 dB instead of 5.17 dB, while for PAM-6 83 GBd the gain becomes 0.8 dB instead of 2.17 dB. The changes are adapted in all sections except the experimental setup and DSP section
Multi-Rate Nyquist-SCM for C-Band 100Gbit/s Signal over 50km Dispersion-Uncompensated Link
Jul 25, 2021
In this paper, to the best of our knowledge, we propose the first multi-rate Nyquist-subcarriers modulation (SCM) for C-band 100Gbit/s signal transmission over 50km dispersion-uncompensated link. Chromatic dispersion (CD) introduces severe spectral nulls on optical double-sideband signal, which greatly degrades the performance of intensity-modulation and direct-detection systems. In the previous works, high-complexity digital signal processing (DSP) is required to resist the CD-caused spectral nulls. Based on the characteristics of dispersive channel, Nyquist-SCM with multi-rate subcarriers is proposed to keep away from the CD-caused spectral nulls flexibly. Signal on each subcarrier can be individually recovered by a DSP with an acceptable complexity, including the feed-forward equalizer with no more than 31 taps, a two-tap post filter, and maximum likelihood sequence estimation with one memory length. Combining with entropy loading based on probabilistic constellation shaping to maximize the capacity-reach, the C-band 100Gbit/s multi-rate Nyquist-SCM signal over 50km dispersion-uncompensated link can achieve 7% hard-decision forward error correction limit and average normalized generalized mutual information of 0.967. In conclusion, the multi-rate Nyquist-SCM shows great potentials in solving the CD-caused spectral distortions.