Turbulence mitigation with MIMO equalization for orbital angular momentum multiplexing communication

Atmospheric turbulence (AT) induced crosstalk can significantly impair performance of free-space optical (FSO) communication link using orbital angular momentum (OAM) multiplexing. OAM-multiplexed communication is equivalent to the Multiple-input Multiple-output(MIMO) system. And MIMO equalization is a good method to mitigate the crosstalk existing in MIMO system. Based on the reason above, we propose a MIMO equalization turbulence mitigation scheme in an OAM-multiplexed FSO communication link. The numerical simulation results show that MIMO equalization mitigation method can mitigate the effects of AT. The Quaternary Phase Shift Keying (QPSK) signal constellation and bit-error ratio(BER) performances are analyzed.