Adaptive decision threshold algorithm based on a sliding window to reduce BER of free-space optical communication...

Area of Science:

• Optical Engineering
• Wireless Communication
• Signal Processing

Background:

• Free-space optical communication (FSOC) systems are vulnerable to environmental factors like atmospheric turbulence and alignment errors.
• These factors cause signal fluctuations, leading to increased bit error rates (BER) and communication errors.
• Traditional fixed decision threshold (FDT) methods struggle to adapt to these dynamic signal variations.

Purpose of the Study:

• To propose and validate an adaptive decision threshold algorithm based on a sliding window (ADTSW) for FSOC systems.
• To mitigate the impact of signal fluctuations on communication quality.
• To reduce the bit error rate (BER) in FSOC links.

Main Methods:

• Developing an adaptive decision threshold algorithm (ADTSW) that estimates received signal parameters.
• Implementing a sliding window approach to delimit signal amplitude intervals.
• Validating the algorithm's performance through simulations and experimental setups under various conditions.

Main Results:

• The ADTSW algorithm demonstrated a 1-order-of-magnitude reduction in BER compared to the FDT method when signal peak-to-peak values fluctuated.
• Simulations and experiments showed a similar 1-order-of-magnitude BER reduction under weak atmospheric turbulence with varying scintillation.
• The algorithm effectively minimized signal misjudgments, leading to improved communication quality.

Conclusions:

• The proposed ADTSW algorithm is effective in reducing BER for FSOC systems facing signal fluctuations.
• ADTSW offers a significant improvement over FDT methods, enhancing communication reliability.
• This adaptive approach is crucial for robust and high-quality FSOC performance.