An O-OFDM-IM system based on the 3-D constellation map

O-OFDM-IM (Optical Orthogonal Frequency Division Multiplexing with Index Modulation, O-OFDM-IM) adopts the traditional constellation diagram, which will lead to the system error performance cannot achieve the best. Therefore, this paper proposes an O-OFDM-IM scheme based on three-dimensional constellation diagram. Its essence is to reduce the constellation sign error detection rate by increasing the minimum Euclidean distance between the constellation symbols. At the same time, the subcarrier optimization algorithm is introduced to reduce the error probability of the index bit. The results show that the system error performance and transmission rate are significantly improved at large SNR compared with conventional O-OFDM-IM.