An adaptive MIMO optical multi-color transceiver for underwater communication links

Multiple-Input Multiple-Output (MIMO) optical wireless communication systems have emerged as a promising solution for high-speed data transmission in underwater environments. Underwater MIMO optical systems can overcome these challenges by utilizing multiple Light Emitting Diodes (LEDs) at the transmitter and photodetectors at the receiver, enabling enhanced spatial multiplexing and diversity. The use of MIMO significantly improves the data rate, robustness, and overall efficiency of underwater communication networks. This paper focuses on the design and optimization of a MIMO-based optical wireless underwater communication system, where the transmitter is equipped with several LEDs operating at different wavelengths, and the receiver comprises multiple photodiodes, each paired with wavelength-selective optical filters. Spatial equalization is then applied in the electrical domain to reduce the residual crosstalk. We provide both numerical results and smallscale testing to show the effectiveness of the proposed system.