IEEE Photonics Journal (Jan 2023)

A Long-Distance Underwater Wireless Optical Link Enabled by a Solar Array With a Baseline Compensator

  • Zhijian Tong,
  • Xingqi Yang,
  • Yunhai Gao,
  • Hao Zhang,
  • Yufan Zhang,
  • Xiyin Wang,
  • Jing Xu

DOI
https://doi.org/10.1109/JPHOT.2023.3264445
Journal volume & issue
Vol. 15, no. 3
pp. 1 – 8

Abstract

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In this paper, a self-designed solar cell-based optical detector is proposed and demonstrated in a long-distance underwater wireless optical communication (UWOC) link. Benefitting from a large detection area, the detector could successfully capture optical signals with a received power density of 5.62 $\bf{\mu W/c}\mathbf{m}^\mathbf{2}$. To resist the baseline drift caused by the low-frequency cut-off of the system, an envelope detector-based baseline compensator is proposed. Comparing with digital solutions, the proposed compensator could be established in analog domain with common electronic components. With the compensator, a frequency domain equalizer (FDE) and a maximum ratio combing (MRC) algorithm, an 18 Mbps non-return-to-zero (NRZ) on-off keying (OOK) modulated link over an 80 m underwater channel is finally achieved. The proposed baseline compensator could compensate the low-frequency components effectively with low cost. Moreover, under a strong ambient light of approximately 1200 lux, the performance of the link shows little degradation. Our work shows a potential solution of long-distance UWOC system with ambient light tolerance, which is compatible with practical environment.

Keywords