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Published on: March 20, 2017
Efficiency of complex modulation methods in coherent free-space optical links.
Aniceto Belmonte1, Joseph M Kahn
1Technical University of Catalonia, Department of Signal Theory and Communications, 08034 Barcelona, Spain. belmonte@tsc.upc.edu
Achieving high-speed coherent laser communication through atmospheric turbulence requires advanced modulation techniques and sensitive receivers. Effective atmospheric compensation, like phase correction, is crucial for mitigating signal fading and ensuring reliable data transmission.
Area of Science:
- Optical Engineering
- Wireless Communication
- Atmospheric Physics
Background:
- Coherent laser communication systems are susceptible to atmospheric turbulence.
- Turbulence causes signal fading and distortion, limiting data rates.
- Various modulation schemes and compensation techniques exist but require performance evaluation.
Purpose of the Study:
- To evaluate the performance of binary and nonbinary modulation methods for atmospheric laser communication.
- To compare spectral and SNR efficiencies of complex modulations.
- To assess the effectiveness of atmospheric compensation techniques.
Main Methods:
- Simulated and experimental analysis of modulation performance under turbulent conditions.
- Comparison of spectral efficiency and SNR efficiency metrics.
- Investigation of phase correction and diversity combining for atmospheric compensation.
Main Results:
- Complex modulations offer potential for higher data rates but require careful implementation.
- Atmospheric compensation techniques significantly improve signal quality and link stability.
- Receiver sensitivity is a critical factor for high-speed communication.
Conclusions:
- High communication rates in turbulent atmospheres necessitate sensitive receivers.
- Effective mitigation of atmospheric fading through compensation is essential.
- The choice of modulation and compensation strategy impacts overall system performance.
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