We experimentally demonstrate turbulence effect mitigation in a 100-m round-trip orbital-angular-momentum (OAM)multiplexed free-space optical communication link between a ground transmitter and a ground receiver via a retro-reflecting hovering unmanned aerial vehicle (UAV) using multiple-input–multiple-output (MIMO) equalization. In our demonstration, two OAM beams at 1550 nm are transmitted to the UAV through emulated atmospheric turbulence, each carrying a 20-Gbit/s signal. 2 × 2 MIMO equalization is used to mitigate turbulence-induced crosstalk between the two OAM channels. Bit error rates below the 7% overhead forward error correction limit of 3.8 × 10−3 are achieved for both channels.
|Number of pages||4|
|State||Published - 1 Nov 2019|