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Atmospheric turbulence mitigation in an OAM-based MIMO free-space optical link using spatial diversity combined with
Optics Letters
|June 1, 2016
Summary
This study enhances free-space optical communications using orbital angular momentum (OAM) and multiple-input multiple-output (MIMO) by mitigating atmospheric turbulence. Spatial diversity and MIMO equalization successfully recovered OAM data channels even in strong turbulence.
Area of Science:
- Optical Communications
- Wireless Communication Systems
- Signal Processing
Background:
- Atmospheric turbulence significantly degrades free-space optical (FSO) communication performance.
- Orbital angular momentum (OAM) multiplexing offers increased data capacity in FSO systems.
- Multiple-input multiple-output (MIMO) architectures can improve system robustness.
Purpose of the Study:
- To investigate the mitigation of atmospheric turbulence effects in OAM-based FSO communications employing MIMO.
- To evaluate the effectiveness of spatial diversity combined with MIMO equalization for turbulence distortion.
- To demonstrate the recovery of multiple OAM data channels under varying turbulence conditions.
Main Methods:
- Implementation of a 2x2 FSO link utilizing multiplexed OAM modes (ℓ=+1 and ℓ=+3) at each transmitter aperture.
- Application of spatial diversity techniques, specifically selection diversity.
- Integration of MIMO equalization algorithms to counteract turbulence-induced distortions.
Main Results:
- Successful recovery of at least two OAM data channels was experimentally demonstrated.
- The proposed method effectively mitigated distortions caused by both weak and strong atmospheric turbulence.
- Spatial diversity assisted by MIMO equalization proved crucial for reliable OAM signal reception.
Conclusions:
- Spatial diversity combined with MIMO equalization is a viable strategy for robust OAM-based FSO communication systems.
- The proposed approach enhances the reliability of FSO links operating under atmospheric turbulence.
- This research contributes to the advancement of high-capacity, turbulence-resilient optical wireless communication.
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