Enabling technologies for high-speed LED based underwater visible light communications

Underwater optical wireless communication (UWOC) is an interesting area need to be explored. In recent years, underwater visible light communication (UVLC) is expected to act as an alternative candidate in next-generation underwater wireless optical communications for the Internet of Underwater Things. The challenge is that the absorption, scattering, diffraction effect and turbulence of water medium, which can bring large attenuation and nonlinearity penalty. Therefore, it needs to apply lots of advanced modulation formats which including orthogonal frequency division multiplexing (OFDM), discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S OFDM) and carrier-less amplitude and phase modulation (CAP) in UVLC system. What's more, advanced digital signal processing algorithm such as pre/post equalization, nonlinear compensation and other algorithms based on artificial intelligence are needed. In this paper, we introduce three advanced modulation formats including DFT-S OFDM, OFDM and CAP employing probabilistic shaping for high-speed LED based underwater visible light communication.