Field Demonstration of 600-Mbps Cross-Ice Wireless Optical Communication

In this article, a wireless optical communication system suitable for data transmission across sea ice was proposed and verified in a field experiment for the first time. Monte Carlo (MC) simulation was used to explore the optical properties in the ice channel, obtaining the optical signal pulse response and optical energy spatial distribution under different scattering intensities. Subsequently, in field experiments, prototypes were utilized to achieve optical communication through the ice layer from the bottom to the surface, with the water and ice channels spanning 20 cm and 39 cm, respectively. Three modulation formats, on-off keying (OOK), 4-level pulse amplitude modulation (PAM4), and orthogonal frequency division multiplexing (OFDM), were tested in transmission. OOK and PAM4 achieved communication rates of 310 Mbps and 430 Mbps, respectively, by utilizing three equalizers, including a feed-forward equalizer (FFE), a Volterra equalizer (VE), and a Volterra decision feedback equalizer (VDFE), to eliminate inter-symbol interference (ISI) and nonlinear distortion. In addition, compared with the traditional OFDM, the discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) increased the data rate from 440 Mbps to 460 Mbps. Finally, with the assistance of maximum ratio combining (MRC), OOK, PAM4, and OFDM data rates reached a maximum of 390 Mbps, 540 Mbps, and 600 Mbps, respectively. The proposed system verifies the feasibility of high-speed wireless optical communication across ice layers, supporting high-latitude ocean exploration.