Underwater LED light MIMO telecentric optical path technology research

The system capacity can be further improved by building Light Emitting Diode (LED) light Multiple-Input Multiple-Output (MIMO) on the basis of hemispherical array structure, but the MIMO capacity is limited by the degree of sub-channel interference. To reduce the sub-channel interference of hemispherical arrays, this paper proposes a method to control the sub-channel interference of LED optical MIMO based on the telecentric optical path, which can achieve the sub-channel isolation of LED optical MIMO in hemispherical array structure by using the restriction effect of the optical diaphragm on stray light and maintain the stable sub-channel isolation in a large communication range. Compared with the conventional Singular Value Decomposition (SVD)/Space-time Block Coding (STBC)/ optical zoom and other electrical and optical domain LED optical MIMO sub-channel interference control methods, the proposed method has better Bit Error Ratio (BER) performance and lower structural complexity, and improves the robustness of sub-channel correlation to communication distance variation.